QPID-8645: [Broker-J] JUnit 5 tests refactoring for broker-plugins/amqp-0-8-protocol (#183)

diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/QpidExceptionTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/QpidExceptionTest.java
index 07c565f..091c2d3 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/QpidExceptionTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/QpidExceptionTest.java
@@ -30,7 +30,6 @@
 import org.apache.qpid.server.protocol.v0_8.AMQShortString;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-
 /**
  * This test is to ensure that when an AMQException is rethrown that the specified exception is correctly wrapped up.
  * <p>
@@ -40,17 +39,17 @@
  * Re-throwing a Subclass of AMQException that does not have the default AMQException constructor which will force the
  * creation of an AMQException.
  */
-public class QpidExceptionTest extends UnitTestBase
+class QpidExceptionTest extends UnitTestBase
 {
     /**
      * Test that an AMQException will be correctly created and rethrown.
      */
     @Test
-    public void testRethrowGeneric()
+    void rethrowGeneric()
     {
-        QpidException test = new QpidException("refused", new RuntimeException());
+        final QpidException test = new QpidException("refused", new RuntimeException());
 
-        QpidException e = reThrowException(test);
+        final QpidException e = reThrowException(test);
 
         assertEquals(QpidException.class, e.getClass(), "Exception not of correct class");
     }
@@ -59,12 +58,10 @@
      * Test that a subclass of AMQException that has the default constructor will be correctly created and rethrown.
      */
     @Test
-    public void testRethrowAMQESubclass()
+    void rethrowAMQESubclass()
     {
-        AMQFrameDecodingException test = new AMQFrameDecodingException(
-                "Error",
-                                                                       new Exception());
-        QpidException e = reThrowException(test);
+        final AMQFrameDecodingException test = new AMQFrameDecodingException("Error", new Exception());
+        final QpidException e = reThrowException(test);
 
         assertEquals(AMQFrameDecodingException.class, e.getClass(), "Exception not of correct class");
     }
@@ -74,11 +71,11 @@
      * AMQException
      */
     @Test
-    public void testRethrowAMQESubclassNoConstructor()
+    void rethrowAMQESubclassNoConstructor()
     {
-        AMQExceptionSubclass test = new AMQExceptionSubclass("Invalid Argument Exception");
+        final AMQExceptionSubclass test = new AMQExceptionSubclass("Invalid Argument Exception");
 
-        QpidException e = reThrowException(test);
+        final QpidException e = reThrowException(test);
 
         assertEquals(QpidException.class, e.getClass(), "Exception not of correct class");
     }
@@ -86,16 +83,14 @@
     /**
      * Private method to rethrown and validate the basic values of the rethrown
      * @param test Exception to rethrow
-     * @throws QpidException the rethrown exception
      */
-    private QpidException reThrowException(QpidException test)
+    private QpidException reThrowException(final QpidException test)
     {
-        QpidException amqe = test.cloneForCurrentThread();
-        if(test instanceof AMQException)
+        final QpidException amqe = test.cloneForCurrentThread();
+        if (test instanceof AMQException)
         {
             assertEquals(((AMQException) test).getErrorCode(), (long) ((AMQException) amqe).getErrorCode(),
                     "Error code does not match.");
-
         }
         assertTrue(amqe.getMessage().startsWith(test.getMessage()), "Exception message does not start as expected.");
         assertEquals(test, amqe.getCause(), "Test Exception is not set as the cause");
@@ -105,15 +100,15 @@
     }
 
     @Test
-    public void testGetMessageAsString()
+    void getMessageAsString()
     {
-        StringBuilder sb = new StringBuilder();
+        final StringBuilder sb = new StringBuilder();
         for (int i = 0; i < 25; i++)
         {
-            sb.append("message [" + i + "]");
+            sb.append("message [").append(i).append("]");
         }
-        AMQException e = new AMQException(ErrorCodes.INTERNAL_ERROR, sb.toString(), null);
-        AMQShortString message = AMQShortString.validValueOf(e.getMessage());
+        final AMQException e = new AMQException(ErrorCodes.INTERNAL_ERROR, sb.toString(), null);
+        final AMQShortString message = AMQShortString.validValueOf(e.getMessage());
         assertEquals(sb.substring(0, AMQShortString.MAX_LENGTH - 3) + "...", message.toString());
     }
 
@@ -122,8 +117,7 @@
      */
     private static class AMQExceptionSubclass extends QpidException
     {
-
-        public AMQExceptionSubclass(String msg)
+        public AMQExceptionSubclass(final String msg)
         {
             super(msg, null);
         }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQChannelTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQChannelTest.java
index e7d656a..2501a98 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQChannelTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQChannelTest.java
@@ -34,7 +34,6 @@
 
 import java.security.AccessControlException;
 import java.security.Principal;
-import java.util.Collections;
 import java.util.Set;
 
 import javax.security.auth.Subject;
@@ -69,7 +68,8 @@
 import org.apache.qpid.server.virtualhost.QueueManagingVirtualHost;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQChannelTest extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class AMQChannelTest extends UnitTestBase
 {
     public static final AMQShortString ROUTING_KEY = AMQShortString.valueOf("routingKey");
 
@@ -79,12 +79,11 @@
     private MessageDestination _messageDestination;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
+        final TaskExecutor taskExecutor = mock(TaskExecutor.class);
 
-        TaskExecutor taskExecutor = mock(TaskExecutor.class);
-
-        Broker<?> broker = mock(Broker.class);
+        final Broker<?> broker = mock(Broker.class);
         when(broker.getEventLogger()).thenReturn(mock(EventLogger.class));
         when(broker.getContextValue(Long.class, Broker.CHANNEL_FLOW_CONTROL_ENFORCEMENT_TIMEOUT)).thenReturn(1L);
 
@@ -97,16 +96,16 @@
         when(_virtualHost.getPrincipal()).thenReturn(mock(Principal.class));
         when(_virtualHost.getEventLogger()).thenReturn(mock(EventLogger.class));
 
-        AmqpPort<?> port = mock(AmqpPort.class);
+        final AmqpPort<?> port = mock(AmqpPort.class);
         when(port.getChildExecutor()).thenReturn(taskExecutor);
         when(port.getModel()).thenReturn(BrokerModel.getInstance());
         when(port.getContextValue(Integer.class, Connection.MAX_MESSAGE_SIZE)).thenReturn(1);
 
-        AuthenticatedPrincipal authenticatedPrincipal = new AuthenticatedPrincipal(new UsernamePrincipal("user", null));
-        Set<Principal> authenticatedUser = Collections.singleton(authenticatedPrincipal);
-        Subject authenticatedSubject = new Subject(true, authenticatedUser, Collections.<Principal>emptySet(), Collections.<Principal>emptySet());
+        final AuthenticatedPrincipal authenticatedPrincipal = new AuthenticatedPrincipal(new UsernamePrincipal("user", null));
+        final Set<Principal> authenticatedUser = Set.of(authenticatedPrincipal);
+        final Subject authenticatedSubject = new Subject(true, authenticatedUser, Set.of(), Set.of());
 
-        ProtocolOutputConverter protocolOutputConverter = mock(ProtocolOutputConverter.class);
+        final ProtocolOutputConverter protocolOutputConverter = mock(ProtocolOutputConverter.class);
 
         _amqConnection = mock(AMQPConnection_0_8.class);
         when(_amqConnection.getSubject()).thenReturn(authenticatedSubject);
@@ -132,75 +131,72 @@
     }
 
     @Test
-    public void testReceiveExchangeDeleteWhenIfUsedIsSetAndExchangeHasBindings()
+    void receiveExchangeDeleteWhenIfUsedIsSetAndExchangeHasBindings()
     {
-        String testExchangeName = getTestName();
-        Exchange<?> exchange = mock(Exchange.class);
+        final String testExchangeName = getTestName();
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.hasBindings()).thenReturn(true);
         doReturn(exchange).when(_virtualHost).getAttainedMessageDestination(eq(testExchangeName), anyBoolean());
 
-        AMQChannel channel = new AMQChannel(_amqConnection, 1, _messageStore);
+        final AMQChannel channel = new AMQChannel(_amqConnection, 1, _messageStore);
 
         channel.receiveExchangeDelete(AMQShortString.valueOf(testExchangeName), true, false);
 
-        verify(_amqConnection).closeChannelAndWriteFrame(eq(channel),
-                                                         eq(ErrorCodes.IN_USE),
-                                                         eq("Exchange has bindings"));
+        verify(_amqConnection).closeChannelAndWriteFrame(channel, ErrorCodes.IN_USE, "Exchange has bindings");
     }
 
     @Test
-    public void testReceiveExchangeDeleteWhenIfUsedIsSetAndExchangeHasNoBinding()
+    void receiveExchangeDeleteWhenIfUsedIsSetAndExchangeHasNoBinding()
     {
-        Exchange<?> exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.hasBindings()).thenReturn(false);
         doReturn(exchange).when(_virtualHost).getAttainedMessageDestination(eq(getTestName()), anyBoolean());
 
-        AMQChannel channel = new AMQChannel(_amqConnection, 1, _messageStore);
+        final AMQChannel channel = new AMQChannel(_amqConnection, 1, _messageStore);
         channel.receiveExchangeDelete(AMQShortString.valueOf(getTestName()), true, false);
 
         verify(exchange).delete();
     }
 
     @Test
-    public void testOversizedMessageClosesChannel()
+    void oversizedMessageClosesChannel()
     {
         when(_virtualHost.getDefaultDestination()).thenReturn(mock(MessageDestination.class));
 
-        long maximumMessageSize = 1024L;
+        final long maximumMessageSize = 1024L;
         when(_amqConnection.getMaxMessageSize()).thenReturn(maximumMessageSize);
-        AMQChannel channel = new AMQChannel(_amqConnection, 1, _virtualHost.getMessageStore());
+        final AMQChannel channel = new AMQChannel(_amqConnection, 1, _virtualHost.getMessageStore());
 
-        BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
         channel.receiveBasicPublish(AMQShortString.EMPTY_STRING, AMQShortString.EMPTY_STRING, false, false);
         channel.receiveMessageHeader(properties, maximumMessageSize + 1);
 
-        verify(_amqConnection).closeChannelAndWriteFrame(eq(channel),
-                                                         eq(ErrorCodes.MESSAGE_TOO_LARGE),
-                                                         eq("Message size of 1025 greater than allowed maximum of 1024"));
+        verify(_amqConnection).closeChannelAndWriteFrame(channel,
+                                                         ErrorCodes.MESSAGE_TOO_LARGE,
+                                                         "Message size of 1025 greater than allowed maximum of 1024");
 
     }
 
     @Test
-    public void testPublishContentHeaderWhenMessageAuthorizationFails()
+    void publishContentHeaderWhenMessageAuthorizationFails()
     {
         final String impostorId = "impostor";
-        doThrow(new AccessControlException("fail")).when(_amqConnection).checkAuthorizedMessagePrincipal(eq(impostorId));
+        doThrow(new AccessControlException("fail")).when(_amqConnection).checkAuthorizedMessagePrincipal(impostorId);
         when(_virtualHost.getDefaultDestination()).thenReturn(mock(MessageDestination.class));
         when(_virtualHost.getMessageStore()).thenReturn(new NullMessageStore()
         {
             @Override
             public <T extends StorableMessageMetaData> MessageHandle<T> addMessage(final T metaData)
             {
-                MessageHandle messageHandle = new StoredMemoryMessage(1, metaData);
-                return messageHandle;
+                return (MessageHandle) new StoredMemoryMessage(1, metaData);
             }
         });
 
 
-        int channelId = 1;
-        AMQChannel channel = new AMQChannel(_amqConnection, channelId, _virtualHost.getMessageStore());
+        final int channelId = 1;
+        final AMQChannel channel = new AMQChannel(_amqConnection, channelId, _virtualHost.getMessageStore());
 
-        BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
         properties.setUserId(impostorId);
         channel.receiveBasicPublish(AMQShortString.EMPTY_STRING, AMQShortString.EMPTY_STRING, false, false);
         channel.receiveMessageHeader(properties, 0);
@@ -210,7 +206,7 @@
     }
 
     @Test
-    public void testPublishContentHeaderWhenMessageAuthorizationSucceeds()
+    void publishContentHeaderWhenMessageAuthorizationSucceeds()
     {
         when(_virtualHost.getDefaultDestination()).thenReturn(_messageDestination);
         when(_virtualHost.getMessageStore()).thenReturn(new NullMessageStore()
@@ -218,25 +214,22 @@
             @Override
             public <T extends StorableMessageMetaData> MessageHandle<T> addMessage(final T metaData)
             {
-                MessageHandle messageHandle = new StoredMemoryMessage(1, metaData);
-                return messageHandle;
+                return (MessageHandle) new StoredMemoryMessage(1, metaData);
             }
         });
         final ArgumentCaptor<ServerMessage> messageCaptor = ArgumentCaptor.forClass(ServerMessage.class);
         doAnswer(invocation ->
         {
-            ServerMessage message = messageCaptor.getValue();
+            final ServerMessage message = messageCaptor.getValue();
             return new RoutingResult(message);
         }).when(_messageDestination).route(messageCaptor.capture(), eq(ROUTING_KEY.toString()), any(InstanceProperties.class));
-        AMQChannel channel = new AMQChannel(_amqConnection, 1, _virtualHost.getMessageStore());
+        final AMQChannel channel = new AMQChannel(_amqConnection, 1, _virtualHost.getMessageStore());
 
-        BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties properties = new BasicContentHeaderProperties();
         properties.setUserId(_amqConnection.getAuthorizedPrincipal().getName());
         channel.receiveBasicPublish(AMQShortString.EMPTY_STRING, ROUTING_KEY, false, false);
         channel.receiveMessageHeader(properties, 0);
 
-        verify(_messageDestination).route((ServerMessage) any(),
-                                         eq(ROUTING_KEY.toString()),
-                                         any(InstanceProperties.class));
+        verify(_messageDestination).route((ServerMessage) any(), eq(ROUTING_KEY.toString()), any(InstanceProperties.class));
     }
 }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQDecoderTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQDecoderTest.java
index 8f7daf3..c3648b8 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQDecoderTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQDecoderTest.java
@@ -25,12 +25,11 @@
 import static org.junit.jupiter.api.Assertions.fail;
 
 import java.nio.ByteBuffer;
+import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Random;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -49,38 +48,36 @@
 import org.apache.qpid.server.transport.ByteBufferSender;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQDecoderTest extends UnitTestBase
+class AMQDecoderTest extends UnitTestBase
 {
     private static final ByteBuffer EMPTY_BYTE_BUFFER = ByteBuffer.allocate(0);
     private ClientDecoder _decoder;
     private FrameCreatingMethodProcessor _methodProcessor;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _methodProcessor = new FrameCreatingMethodProcessor(ProtocolVersion.v0_91);
         _decoder = new ClientDecoder(_methodProcessor);
     }
 
-
     private ByteBuffer getHeartbeatBodyBuffer()
     {
-        TestSender sender = new TestSender();
+        final TestSender sender = new TestSender();
         HeartbeatBody.FRAME.writePayload(sender);
         return combine(sender.getSentBuffers());
     }
 
     @Test
-    public void testSingleFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void singleFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
-        ByteBuffer msg = getHeartbeatBodyBuffer();
+        final ByteBuffer msg = getHeartbeatBodyBuffer();
         _decoder.decodeBuffer(msg);
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
         if (frames.get(0) instanceof AMQFrame)
         {
             assertEquals(HeartbeatBody.FRAME.getBodyFrame().getFrameType(),
                     (long) ((AMQFrame) frames.get(0)).getBodyFrame().getFrameType());
-
         }
         else
         {
@@ -88,29 +85,27 @@
         }
     }
 
-
     @Test
-    public void testContentHeaderPropertiesFrame() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void contentHeaderPropertiesFrame() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
         final BasicContentHeaderProperties props = new BasicContentHeaderProperties();
-        Map<String, Object> headersMap = new LinkedHashMap<>();
-        headersMap.put("hello","world");
-        headersMap.put("1+1=",2);
+        final Map<String, Object> headersMap = Map.of("hello", "world",
+                "1+1=", 2);
         final FieldTable table = FieldTableFactory.createFieldTable(headersMap);
         props.setHeaders(table);
         final AMQBody body = new ContentHeaderBody(props);
-        AMQFrame frame = new AMQFrame(1, body);
-        TestSender sender = new TestSender();
+        final AMQFrame frame = new AMQFrame(1, body);
+        final TestSender sender = new TestSender();
         frame.writePayload(sender);
-        ByteBuffer msg = combine(sender.getSentBuffers());
+        final ByteBuffer msg = combine(sender.getSentBuffers());
 
         _decoder.decodeBuffer(msg);
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
-        AMQDataBlock firstFrame = frames.get(0);
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final AMQDataBlock firstFrame = frames.get(0);
         if (firstFrame instanceof AMQFrame)
         {
             assertEquals(ContentHeaderBody.TYPE, (long) ((AMQFrame) firstFrame).getBodyFrame().getFrameType());
-            BasicContentHeaderProperties decodedProps = ((ContentHeaderBody)((AMQFrame)firstFrame).getBodyFrame()).getProperties();
+            final BasicContentHeaderProperties decodedProps = ((ContentHeaderBody)((AMQFrame)firstFrame).getBodyFrame()).getProperties();
             final Map<String, Object> headers = decodedProps.getHeadersAsMap();
             assertEquals("world", headers.get("hello"));
         }
@@ -122,32 +117,31 @@
 
 
     @Test
-    public void testDecodeWithManyBuffers() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void decodeWithManyBuffers() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
-        Random random = new Random();
+        final SecureRandom random = new SecureRandom();
         final byte[] payload = new byte[2048];
         random.nextBytes(payload);
         final AMQBody body = new ContentBody(ByteBuffer.wrap(payload));
-        AMQFrame frame = new AMQFrame(1, body);
-        TestSender sender = new TestSender();
+        final AMQFrame frame = new AMQFrame(1, body);
+        final TestSender sender = new TestSender();
         frame.writePayload(sender);
-        ByteBuffer allData = combine(sender.getSentBuffers());
+        final ByteBuffer allData = combine(sender.getSentBuffers());
 
-
-        for(int i = 0 ; i < allData.remaining(); i++)
+        for (int i = 0 ; i < allData.remaining(); i++)
         {
-            byte[] minibuf = new byte[1];
+            final byte[] minibuf = new byte[1];
             minibuf[0] = allData.get(i);
             _decoder.decodeBuffer(ByteBuffer.wrap(minibuf));
         }
 
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
         if (frames.get(0) instanceof AMQFrame)
         {
             assertEquals(ContentBody.TYPE, (long) ((AMQFrame) frames.get(0)).getBodyFrame().getFrameType());
-            ContentBody decodedBody = (ContentBody) ((AMQFrame) frames.get(0)).getBodyFrame();
+            final ContentBody decodedBody = (ContentBody) ((AMQFrame) frames.get(0)).getBodyFrame();
             byte[] bodyBytes;
-            try (QpidByteBuffer payloadBuffer = decodedBody.getPayload())
+            try (final QpidByteBuffer payloadBuffer = decodedBody.getPayload())
             {
                 bodyBytes = new byte[payloadBuffer.remaining()];
                 payloadBuffer.get(bodyBytes);
@@ -161,18 +155,18 @@
     }
 
     @Test
-    public void testPartialFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void partialFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
-        ByteBuffer msg = getHeartbeatBodyBuffer();
-        ByteBuffer msgA = msg.slice();
-        int msgbPos = msg.remaining() / 2;
-        int msgaLimit = msg.remaining() - msgbPos;
+        final  ByteBuffer msg = getHeartbeatBodyBuffer();
+        final ByteBuffer msgA = msg.slice();
+        final int msgbPos = msg.remaining() / 2;
+        final int msgaLimit = msg.remaining() - msgbPos;
         msgA.limit(msgaLimit);
         msg.position(msgbPos);
-        ByteBuffer msgB = msg.slice();
+        final ByteBuffer msgB = msg.slice();
 
         _decoder.decodeBuffer(msgA);
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
         assertEquals(0, (long) frames.size());
 
         _decoder.decodeBuffer(msgB);
@@ -189,18 +183,18 @@
     }
 
     @Test
-    public void testMultipleFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void multipleFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
-        ByteBuffer msgA = getHeartbeatBodyBuffer();
-        ByteBuffer msgB = getHeartbeatBodyBuffer();
-        ByteBuffer msg = ByteBuffer.allocate(msgA.remaining() + msgB.remaining());
+        final ByteBuffer msgA = getHeartbeatBodyBuffer();
+        final ByteBuffer msgB = getHeartbeatBodyBuffer();
+        final ByteBuffer msg = ByteBuffer.allocate(msgA.remaining() + msgB.remaining());
         msg.put(msgA);
         msg.put(msgB);
         msg.flip();
         _decoder.decodeBuffer(msg);
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
         assertEquals(2, (long) frames.size());
-        for (AMQDataBlock frame : frames)
+        for (final AMQDataBlock frame : frames)
         {
             if (frame instanceof AMQFrame)
             {
@@ -215,23 +209,23 @@
     }
 
     @Test
-    public void testMultiplePartialFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
+    void multiplePartialFrameDecode() throws AMQProtocolVersionException, AMQFrameDecodingException
     {
-        ByteBuffer msgA = getHeartbeatBodyBuffer();
-        ByteBuffer msgB = getHeartbeatBodyBuffer();
-        ByteBuffer msgC = getHeartbeatBodyBuffer();
+        final ByteBuffer msgA = getHeartbeatBodyBuffer();
+        final ByteBuffer msgB = getHeartbeatBodyBuffer();
+        final ByteBuffer msgC = getHeartbeatBodyBuffer();
 
-        ByteBuffer sliceA = ByteBuffer.allocate(msgA.remaining() + msgB.remaining() / 2);
+        final ByteBuffer sliceA = ByteBuffer.allocate(msgA.remaining() + msgB.remaining() / 2);
         sliceA.put(msgA);
-        int limit = msgB.limit();
-        int pos = msgB.remaining() / 2;
+        final int limit = msgB.limit();
+        final int pos = msgB.remaining() / 2;
         msgB.limit(pos);
         sliceA.put(msgB);
         sliceA.flip();
         msgB.limit(limit);
         msgB.position(pos);
 
-        ByteBuffer sliceB = ByteBuffer.allocate(msgB.remaining() + pos);
+        final ByteBuffer sliceB = ByteBuffer.allocate(msgB.remaining() + pos);
         sliceB.put(msgB);
         msgC.limit(pos);
         sliceB.put(msgC);
@@ -239,7 +233,7 @@
         msgC.limit(limit);
 
         _decoder.decodeBuffer(sliceA);
-        List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
+        final List<AMQDataBlock> frames = _methodProcessor.getProcessedMethods();
         assertEquals(1, (long) frames.size());
         frames.clear();
         _decoder.decodeBuffer(sliceB);
@@ -247,7 +241,7 @@
         frames.clear();
         _decoder.decodeBuffer(msgC);
         assertEquals(1, (long) frames.size());
-        for (AMQDataBlock frame : frames)
+        for (final AMQDataBlock frame : frames)
         {
             if (frame instanceof AMQFrame)
             {
@@ -263,8 +257,8 @@
 
     private static class TestSender implements ByteBufferSender
     {
-
         private final Collection<QpidByteBuffer> _sentBuffers = new ArrayList<>();
+
         @Override
         public boolean isDirectBufferPreferred()
         {
@@ -297,9 +291,9 @@
 
     }
 
-    private static ByteBuffer combine(Collection<QpidByteBuffer> bufs)
+    private static ByteBuffer combine(final Collection<QpidByteBuffer> bufs)
     {
-        if(bufs == null || bufs.isEmpty())
+        if (bufs == null || bufs.isEmpty())
         {
             return EMPTY_BYTE_BUFFER;
         }
@@ -307,14 +301,14 @@
         {
             int size = 0;
             boolean isDirect = false;
-            for(QpidByteBuffer buf : bufs)
+            for (final QpidByteBuffer buf : bufs)
             {
                 size += buf.remaining();
                 isDirect = isDirect || buf.isDirect();
             }
-            ByteBuffer combined = isDirect ? ByteBuffer.allocateDirect(size) : ByteBuffer.allocate(size);
+            final ByteBuffer combined = isDirect ? ByteBuffer.allocateDirect(size) : ByteBuffer.allocate(size);
 
-            for(QpidByteBuffer buf : bufs)
+            for (final QpidByteBuffer buf : bufs)
             {
                 buf.copyTo(combined);
             }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQMessageMutatorTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQMessageMutatorTest.java
index 1145594..e6f7cba 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQMessageMutatorTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQMessageMutatorTest.java
@@ -25,7 +25,7 @@
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
 
-import java.util.Collections;
+import java.util.Map;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -40,56 +40,56 @@
 import org.apache.qpid.server.store.TestMemoryMessageStore;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQMessageMutatorTest extends UnitTestBase
+class AMQMessageMutatorTest extends UnitTestBase
 {
     private static final byte TEST_PRIORITY = (byte) 1;
     private static final String TEST_HEADER_NAME = "foo";
     private static final String TEST_HEADER_VALUE = "bar";
     private static final String TEST_CONTENT_TYPE = "text/plain";
     private static final String TEST_CONTENT = "testContent";
+
     private MessageStore _messageStore;
     private AMQMessageMutator _messageMutator;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _messageStore = new TestMemoryMessageStore();
         final AMQMessage message = createTestMessage();
         _messageMutator = new AMQMessageMutator(message, _messageStore);
     }
 
-
     @AfterEach
-    public void tearDown()
+    void tearDown()
     {
         _messageStore.closeMessageStore();
     }
 
     @Test
-    public void setPriority()
+    void setPriority()
     {
         _messageMutator.setPriority((byte) (TEST_PRIORITY + 1));
         assertThat(_messageMutator.getPriority(), is(equalTo((byte) (TEST_PRIORITY + 1))));
     }
 
     @Test
-    public void getPriority()
+    void getPriority()
     {
         assertThat((int) _messageMutator.getPriority(), is(equalTo((int) TEST_PRIORITY)));
     }
 
     @Test
-    public void create()
+    void create()
     {
         _messageMutator.setPriority((byte) (TEST_PRIORITY + 1));
 
-        AMQMessage newMessage = _messageMutator.create();
+        final AMQMessage newMessage = _messageMutator.create();
 
         assertThat(newMessage.getMessageHeader().getPriority(), is(equalTo((byte) (TEST_PRIORITY + 1))));
         assertThat(newMessage.getMessageHeader().getMimeType(), is(equalTo(TEST_CONTENT_TYPE)));
         assertThat(newMessage.getMessageHeader().getHeader(TEST_HEADER_NAME), is(equalTo(TEST_HEADER_VALUE)));
 
-        QpidByteBuffer content = newMessage.getContent();
+        final QpidByteBuffer content = newMessage.getContent();
 
         final byte[] bytes = new byte[content.remaining()];
         content.copyTo(bytes);
@@ -100,18 +100,17 @@
     {
         final BasicContentHeaderProperties basicContentHeaderProperties = new BasicContentHeaderProperties();
         basicContentHeaderProperties.setPriority(TEST_PRIORITY);
-        basicContentHeaderProperties.setHeaders(FieldTableFactory.createFieldTable(Collections.singletonMap(
-                TEST_HEADER_NAME,
-                TEST_HEADER_VALUE)));
+        basicContentHeaderProperties
+                .setHeaders(FieldTableFactory.createFieldTable(Map.of(TEST_HEADER_NAME, TEST_HEADER_VALUE)));
         basicContentHeaderProperties.setContentType(TEST_CONTENT_TYPE);
 
-        QpidByteBuffer content = QpidByteBuffer.wrap(TEST_CONTENT.getBytes(UTF_8));
+        final QpidByteBuffer content = QpidByteBuffer.wrap(TEST_CONTENT.getBytes(UTF_8));
 
         final ContentHeaderBody contentHeader = new ContentHeaderBody(basicContentHeaderProperties, content.remaining());
         final MessagePublishInfo publishInfo = new MessagePublishInfo(AMQShortString.valueOf("testExchange"),
-                                                                      true,
-                                                                      true,
-                                                                      AMQShortString.valueOf("testRoutingKey"));
+                true,
+                true,
+                AMQShortString.valueOf("testRoutingKey"));
         final MessageMetaData messageMetaData =
                 new MessageMetaData(publishInfo, contentHeader, System.currentTimeMillis());
         final MessageHandle<MessageMetaData> handle = _messageStore.addMessage(messageMetaData);
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQPConnection_0_8Test.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQPConnection_0_8Test.java
index 8833699..a7912a3 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQPConnection_0_8Test.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQPConnection_0_8Test.java
@@ -31,7 +31,7 @@
 import static org.mockito.Mockito.when;
 
 import java.net.InetSocketAddress;
-import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 
 import javax.security.auth.Subject;
@@ -73,7 +73,8 @@
 import org.apache.qpid.server.virtualhost.VirtualHostPrincipal;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQPConnection_0_8Test extends UnitTestBase
+@SuppressWarnings({"rawtypes"})
+class AMQPConnection_0_8Test extends UnitTestBase
 {
     private static final String VIRTUAL_HOST_NAME = "vhost";
     private static final byte[] SASL_RESPONSE = "response".getBytes();
@@ -82,7 +83,6 @@
 
     private TaskExecutorImpl _taskExecutor;
     private Broker _broker;
-    private VirtualHostNode _virtualHostNode;
     private QueueManagingVirtualHost _virtualHost;
     private AmqpPort _port;
     private ServerNetworkConnection _network;
@@ -91,18 +91,17 @@
     private AggregateTicker _ticker;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
+        final EventLogger value = new EventLogger();
 
-        EventLogger value = new EventLogger();
-
-        SystemConfig systemConfig = mock(SystemConfig.class);
+        final SystemConfig systemConfig = mock(SystemConfig.class);
         when(systemConfig.getEventLogger()).thenReturn(mock(EventLogger.class));
 
         _taskExecutor = new TaskExecutorImpl();
         _taskExecutor.start();
 
-        Model model = BrokerModel.getInstance();
+        final Model model = BrokerModel.getInstance();
 
         _broker = mock(Broker.class);
         when(_broker.getParent()).thenReturn(systemConfig);
@@ -111,18 +110,18 @@
         when(_broker.getTaskExecutor()).thenReturn(_taskExecutor);
         when(_broker.getChildExecutor()).thenReturn(_taskExecutor);
         when(_broker.getEventLogger()).thenReturn(value);
-        when(_broker.getContextValue(eq(Long.class), eq(Broker.CHANNEL_FLOW_CONTROL_ENFORCEMENT_TIMEOUT))).thenReturn(0L);
+        when(_broker.getContextValue(Long.class, Broker.CHANNEL_FLOW_CONTROL_ENFORCEMENT_TIMEOUT)).thenReturn(0L);
 
-        _virtualHostNode = mock(VirtualHostNode.class);
-        when(_virtualHostNode.getParent()).thenReturn(_broker);
-        when(_virtualHostNode.getModel()).thenReturn(model);
-        when(_virtualHostNode.getCategoryClass()).thenReturn(VirtualHostNode.class);
-        when(_virtualHostNode.getTaskExecutor()).thenReturn(_taskExecutor);
-        when(_virtualHostNode.getChildExecutor()).thenReturn(_taskExecutor);
+        final VirtualHostNode virtualHostNode = mock(VirtualHostNode.class);
+        when(virtualHostNode.getParent()).thenReturn(_broker);
+        when(virtualHostNode.getModel()).thenReturn(model);
+        when(virtualHostNode.getCategoryClass()).thenReturn(VirtualHostNode.class);
+        when(virtualHostNode.getTaskExecutor()).thenReturn(_taskExecutor);
+        when(virtualHostNode.getChildExecutor()).thenReturn(_taskExecutor);
 
         _virtualHost = mock(QueueManagingVirtualHost.class);
-        VirtualHostPrincipal virtualHostPrincipal = new VirtualHostPrincipal(_virtualHost);
-        when(_virtualHost.getParent()).thenReturn(_virtualHostNode);
+        final VirtualHostPrincipal virtualHostPrincipal = new VirtualHostPrincipal(_virtualHost);
+        when(_virtualHost.getParent()).thenReturn(virtualHostNode);
         when(_virtualHost.getModel()).thenReturn(model);
         when(_virtualHost.getCategoryClass()).thenReturn(VirtualHost.class);
         when(_virtualHost.getState()).thenReturn(State.ACTIVE);
@@ -136,16 +135,15 @@
         when(_virtualHost.authoriseCreateConnection(any(AMQPConnection.class))).thenReturn(true);
         when(_virtualHost.getEventLogger()).thenReturn(value);
 
-        SubjectCreator subjectCreator = mock(SubjectCreator.class);
+        final SubjectCreator subjectCreator = mock(SubjectCreator.class);
 
-
-        SaslNegotiator saslNegotiator = mock(SaslNegotiator.class);
+        final SaslNegotiator saslNegotiator = mock(SaslNegotiator.class);
         when(subjectCreator.createSaslNegotiator(eq(SASL_MECH.toString()), any(SaslSettings.class))).thenReturn(saslNegotiator);
         when(subjectCreator.authenticate(saslNegotiator, SASL_RESPONSE)).thenReturn(new SubjectAuthenticationResult(
                 new AuthenticationResult(new AuthenticatedPrincipal(new UsernamePrincipal("username", null))), new Subject()));
 
-        AuthenticationProvider authenticationProvider = mock(AuthenticationProvider.class);
-        when(authenticationProvider.getAvailableMechanisms(anyBoolean())).thenReturn(Collections.singletonList(SASL_MECH.toString()));
+        final AuthenticationProvider authenticationProvider = mock(AuthenticationProvider.class);
+        when(authenticationProvider.getAvailableMechanisms(anyBoolean())).thenReturn(List.of(SASL_MECH.toString()));
 
         _port = mock(AmqpPort.class);
         when(_port.getParent()).thenReturn(_broker);
@@ -158,7 +156,7 @@
         when(_port.getContextValue(Integer.class, Connection.MAX_MESSAGE_SIZE)).thenReturn(Connection.DEFAULT_MAX_MESSAGE_SIZE);
         when(_port.getSubjectCreator(eq(false), anyString())).thenReturn(subjectCreator);
 
-        ByteBufferSender sender = mock(ByteBufferSender.class);
+        final ByteBufferSender sender = mock(ByteBufferSender.class);
 
         _network = mock(ServerNetworkConnection.class);
         when(_network.getSender()).thenReturn(sender);
@@ -171,57 +169,55 @@
     }
 
     @AfterEach
-    public void tearDown() throws Exception
+    void tearDown()
     {
         _taskExecutor.stopImmediately();
     }
 
     @Test
-    public void testCloseOnNoRoute()
+    void closeOnNoRoute()
     {
         {
-            AMQPConnection_0_8Impl
+            final AMQPConnection_0_8Impl
                     conn = new AMQPConnection_0_8Impl(_broker, _network, _port, _transport, _protocol, 0, _ticker);
             conn.create();
             conn.receiveProtocolHeader(new ProtocolInitiation(ProtocolVersion.v0_8));
 
-            FieldTable startFieldTable = FieldTable.convertToFieldTable(Collections.singletonMap(
-                    ConnectionStartProperties.QPID_CLOSE_WHEN_NO_ROUTE,
-                    Boolean.TRUE));
+            final FieldTable startFieldTable = FieldTable
+                    .convertToFieldTable(Map.of(ConnectionStartProperties.QPID_CLOSE_WHEN_NO_ROUTE, Boolean.TRUE));
             conn.receiveConnectionStartOk(startFieldTable, SASL_MECH, SASL_RESPONSE, LOCALE);
 
             assertTrue(conn.isCloseWhenNoRoute(), "Unexpected closeWhenNoRoute value");
         }
 
         {
-            AMQPConnection_0_8Impl
+            final AMQPConnection_0_8Impl
                     conn = new AMQPConnection_0_8Impl(_broker, _network, _port, _transport, _protocol, 0, _ticker);
             conn.create();
             conn.receiveProtocolHeader(new ProtocolInitiation(ProtocolVersion.v0_8));
 
-            FieldTable startFieldTable = FieldTable.convertToFieldTable(Collections.singletonMap(
-                    ConnectionStartProperties.QPID_CLOSE_WHEN_NO_ROUTE,
-                    Boolean.FALSE));
+            final FieldTable startFieldTable = FieldTable
+                    .convertToFieldTable(Map.of(ConnectionStartProperties.QPID_CLOSE_WHEN_NO_ROUTE, Boolean.FALSE));
             conn.receiveConnectionStartOk(startFieldTable, SASL_MECH, SASL_RESPONSE, LOCALE);
             assertFalse(conn.isCloseWhenNoRoute(), "Unexpected closeWhenNoRoute value");
         }
     }
 
     @Test
-    public void testConnectionEnforcesMaxSessions()
+    void connectionEnforcesMaxSessions()
     {
-        AMQPConnection_0_8Impl
+        final AMQPConnection_0_8Impl
                 conn = new AMQPConnection_0_8Impl(_broker, _network, _port, _transport, _protocol, 0, _ticker);
         conn.create();
 
         conn.receiveProtocolHeader(new ProtocolInitiation(ProtocolVersion.v0_8));
-        conn.receiveConnectionStartOk(FieldTableFactory.createFieldTable(Collections.emptyMap()), SASL_MECH, SASL_RESPONSE, LOCALE);
-        int maxChannels = 10;
+        conn.receiveConnectionStartOk(FieldTableFactory.createFieldTable(Map.of()), SASL_MECH, SASL_RESPONSE, LOCALE);
+        final int maxChannels = 10;
         conn.receiveConnectionTuneOk(maxChannels, 65535, 0);
         conn.receiveConnectionOpen(AMQShortString.createAMQShortString(VIRTUAL_HOST_NAME), AMQShortString.EMPTY_STRING, false);
 
         // check the channel count is correct
-        int channelCount = conn.getSessionModels().size();
+        final int channelCount = conn.getSessionModels().size();
         assertEquals(0, (long) channelCount, "Initial channel count wrong");
 
         assertEquals(maxChannels, (long) conn.getSessionCountLimit(), "Number of channels not correctly set.");
@@ -240,7 +236,7 @@
     }
 
     @Test
-    public void resetStatistics()
+    void resetStatistics()
     {
         final AMQPConnection_0_8Impl connection =
                 new AMQPConnection_0_8Impl(_broker, _network, _port, _transport, _protocol, 0, _ticker);
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQShortStringTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQShortStringTest.java
index 1238877..a6db0d5 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQShortStringTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQShortStringTest.java
@@ -22,8 +22,9 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertSame;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
@@ -36,12 +37,12 @@
 import org.apache.qpid.server.bytebuffer.QpidByteBuffer;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQShortStringTest extends UnitTestBase
+class AMQShortStringTest extends UnitTestBase
 {
     private static final AMQShortString GOODBYE = AMQShortString.createAMQShortString("Goodbye");
 
     @Test
-    public void testEquals()
+    void testEquals()
     {
         assertEquals(GOODBYE, AMQShortString.createAMQShortString("Goodbye"));
         assertEquals(AMQShortString.createAMQShortString("A"), AMQShortString.createAMQShortString("A"));
@@ -53,12 +54,11 @@
      * {@link AMQShortString#AMQShortString(byte[])}.
      */
     @Test
-    public void testCreateAMQShortStringByteArray()
+    void createAMQShortStringByteArray()
     {
-        byte[] bytes = "test".getBytes(StandardCharsets.UTF_8);
-        AMQShortString string = AMQShortString.createAMQShortString(bytes);
+        final byte[] bytes = "test".getBytes(StandardCharsets.UTF_8);
+        final AMQShortString string = AMQShortString.createAMQShortString(bytes);
         assertEquals(4, (long) string.length(), "constructed amq short string length differs from expected");
-
         assertEquals("test", string.toString(), "constructed amq short string differs from expected");
     }
 
@@ -66,11 +66,10 @@
      * Tests short string construction from string with length less than 255.
      */
     @Test
-    public void testCreateAMQShortStringString()
+    void createAMQShortStringString()
     {
-        AMQShortString string = AMQShortString.createAMQShortString("test");
+        final AMQShortString string = AMQShortString.createAMQShortString("test");
         assertEquals(4, (long) string.length(), "constructed amq short string length differs from expected");
-
         assertEquals("test", string.toString(), "constructed amq short string differs from expected");
     }
 
@@ -81,90 +80,79 @@
      * Tests an attempt to create an AMQP short string from byte array with length over 255.
      */
     @Test
-    public void testCreateAMQShortStringByteArrayOver255()
+    void createAMQShortStringByteArrayOver255()
     {
-        String test = buildString('a', 256);
-        byte[] bytes = test.getBytes(StandardCharsets.UTF_8);
-        try
-        {
-            AMQShortString.createAMQShortString(bytes);
-            fail("It should not be possible to create AMQShortString with length over 255");
-        }
-        catch (IllegalArgumentException e)
-        {
-            assertEquals("Cannot create AMQShortString with number of octets over 255!", e.getMessage(),
-                    "Exception message differs from expected");
-
-        }
+        final String test = buildString(256);
+        final byte[] bytes = test.getBytes(StandardCharsets.UTF_8);
+        final IllegalArgumentException thrown = assertThrows(IllegalArgumentException.class,
+                () -> AMQShortString.createAMQShortString(bytes),
+                "It should not be possible to create AMQShortString with length over 255");
+        assertEquals("Cannot create AMQShortString with number of octets over 255!", thrown.getMessage(),
+                "Exception message differs from expected");
     }
 
     /**
      * Tests an attempt to create an AMQP short string from string with length over 255
      */
     @Test
-    public void testCreateAMQShortStringStringOver255()
+    void createAMQShortStringStringOver255()
     {
-        String test = buildString('a', 256);
-        try
-        {
-            AMQShortString.createAMQShortString(test);
-            fail("It should not be possible to create AMQShortString with length over 255");
-        }
-        catch (IllegalArgumentException e)
-        {
-            assertEquals("Cannot create AMQShortString with number of octets over 255!", e.getMessage(),
-                    "Exception message differs from expected");
-        }
+        final String test = buildString(256);
+        final IllegalArgumentException thrown = assertThrows(IllegalArgumentException.class,
+                () -> AMQShortString.createAMQShortString(test),
+                "It should not be possible to create AMQShortString with length over 255");
+        assertEquals("Cannot create AMQShortString with number of octets over 255!", thrown.getMessage(),
+                "Exception message differs from expected");
     }
 
     @Test
-    public void testValueOf()
+    void valueOf()
     {
-        String string = buildString('a', 255);
-        AMQShortString shortString = AMQShortString.valueOf(string, true, true);
+        final String string = buildString(255);
+        final AMQShortString shortString = AMQShortString.valueOf(string, true, true);
         assertEquals(string, shortString.toString(), "Unexpected string from valueOf");
     }
 
     @Test
-    public void testValueOfTruncated()
+    void valueOfTruncated()
     {
-        String string = buildString('a', 256);
-        AMQShortString shortString = AMQShortString.valueOf(string, true, true);
+        final String string = buildString(256);
+        final AMQShortString shortString = AMQShortString.valueOf(string, true, true);
         assertEquals(string.substring(0, AMQShortString.MAX_LENGTH - 3) + "...", shortString.toString(),
                 "Unexpected truncated string from valueOf");
     }
 
     @Test
-    public void testValueOfNulAsEmptyString()
+    void valueOfNulAsEmptyString()
     {
-        AMQShortString shortString = AMQShortString.valueOf(null, true, true);
+        final AMQShortString shortString = AMQShortString.valueOf(null, true, true);
         assertEquals(AMQShortString.EMPTY_STRING, shortString, "Unexpected empty string from valueOf");
     }
 
     @Test
-    public void testValueOfNullAsNull()
+    void valueOfNullAsNull()
     {
-        AMQShortString shortString = AMQShortString.valueOf(null, true, false);
-        assertEquals(null, shortString, "Unexpected null string from valueOf");
+        final AMQShortString shortString = AMQShortString.valueOf(null, true, false);
+        assertNull(shortString, "Unexpected null string from valueOf");
     }
 
     @Test
-    public void testCaching()
+    void caching()
     {
-        Cache<ByteBuffer, AMQShortString> original = AMQShortString.getShortStringCache();
-        Cache<ByteBuffer, AMQShortString> cache = CacheBuilder.newBuilder().maximumSize(1).build();
+        final Cache<ByteBuffer, AMQShortString> original = AMQShortString.getShortStringCache();
+        final Cache<ByteBuffer, AMQShortString> cache = CacheBuilder.newBuilder().maximumSize(1).build();
         AMQShortString.setShortStringCache(cache);
         try
         {
-            AMQShortString string = AMQShortString.createAMQShortString("hello");
-            QpidByteBuffer qpidByteBuffer = QpidByteBuffer.allocate(2 * (string.length() + 1));
+            final AMQShortString string = AMQShortString.createAMQShortString("hello");
+            final QpidByteBuffer qpidByteBuffer = QpidByteBuffer.allocate(2 * (string.length() + 1));
             string.writeToBuffer(qpidByteBuffer);
             string.writeToBuffer(qpidByteBuffer);
 
             qpidByteBuffer.flip();
 
-            AMQShortString str1 = AMQShortString.readAMQShortString(qpidByteBuffer);
-            AMQShortString str2 = AMQShortString.readAMQShortString(qpidByteBuffer);
+            final AMQShortString str1 = AMQShortString.readAMQShortString(qpidByteBuffer);
+            final AMQShortString str2 = AMQShortString.readAMQShortString(qpidByteBuffer);
 
             assertEquals(str1, str2);
             assertSame(str1, str2);
@@ -180,20 +168,11 @@
      * A helper method to generate a string with given length containing given
      * character
      *
-     * @param ch
-     *            char to build string with
-     * @param length
-     *            target string length
+     * @param length target string length
      * @return string
      */
-    private String buildString(char ch, int length)
+    private String buildString(int length)
     {
-        StringBuilder sb = new StringBuilder();
-        for (int i = 0; i < length; i++)
-        {
-            sb.append(ch);
-        }
-        return sb.toString();
+        return String.valueOf('a').repeat(Math.max(0, length));
     }
-
 }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQTypeTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQTypeTest.java
index 79e294f..6b01d64 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQTypeTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/AMQTypeTest.java
@@ -27,19 +27,20 @@
 import org.apache.qpid.server.bytebuffer.QpidByteBuffer;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class AMQTypeTest extends UnitTestBase
+@SuppressWarnings("unchecked")
+class AMQTypeTest extends UnitTestBase
 {
     private static final int SIZE = 1024;
 
     @Test
-    public void testUnsignedShort()
+    void unsignedShort()
     {
         doTest(AMQType.UNSIGNED_SHORT, 0);
         doTest(AMQType.UNSIGNED_SHORT, 65535);
     }
 
     @Test
-    public void testUnsignedByte()
+    void unsignedByte()
     {
         doTest(AMQType.UNSIGNED_BYTE, (short)0);
         doTest(AMQType.UNSIGNED_BYTE, (short)255);
@@ -51,7 +52,7 @@
         AMQTypedValue.createAMQTypedValue(type, value).writeToBuffer(buf);
         buf.flip();
 
-        T read = (T) AMQTypedValue.readFromBuffer(buf).getValue();
+        final T read = (T) AMQTypedValue.readFromBuffer(buf).getValue();
         assertEquals(value, read, "Unexpected round trip value");
         buf.dispose();
     }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ClientDecoder.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ClientDecoder.java
index 8e02bbb..e08d9d7 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ClientDecoder.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ClientDecoder.java
@@ -33,18 +33,18 @@
     /**
      * Creates a new AMQP decoder.
      *
-     * @param methodProcessor          method processor
+     * @param methodProcessor method processor
      */
     public ClientDecoder(final ClientMethodProcessor<? extends ClientChannelMethodProcessor> methodProcessor)
     {
         super(false, methodProcessor);
     }
 
-    public void decodeBuffer(ByteBuffer incomingBuffer) throws AMQFrameDecodingException, AMQProtocolVersionException
+    public void decodeBuffer(final ByteBuffer incomingBuffer) throws AMQFrameDecodingException, AMQProtocolVersionException
     {
         if (_incompleteBuffer == null)
         {
-            QpidByteBuffer qpidByteBuffer = QpidByteBuffer.wrap(incomingBuffer);
+            final QpidByteBuffer qpidByteBuffer = QpidByteBuffer.wrap(incomingBuffer);
             final int required = decode(qpidByteBuffer);
             if (required != 0)
             {
@@ -86,15 +86,13 @@
     }
 
     @Override
-    protected void processMethod(int channelId,
-                       QpidByteBuffer in)
-            throws AMQFrameDecodingException
+    protected void processMethod(final int channelId, final QpidByteBuffer in) throws AMQFrameDecodingException
     {
-        ClientMethodProcessor<? extends ClientChannelMethodProcessor> methodProcessor = getMethodProcessor();
-        ClientChannelMethodProcessor channelMethodProcessor = methodProcessor.getChannelMethodProcessor(channelId);
+        final ClientMethodProcessor<? extends ClientChannelMethodProcessor> methodProcessor = getMethodProcessor();
+        final ClientChannelMethodProcessor channelMethodProcessor = methodProcessor.getChannelMethodProcessor(channelId);
         final int classAndMethod = in.getInt();
-        int classId = classAndMethod >> 16;
-        int methodId = classAndMethod & 0xFFFF;
+        final int classId = classAndMethod >> 16;
+        final int methodId = classAndMethod & 0xFFFF;
         methodProcessor.setCurrentMethod(classId, methodId);
         try
         {
@@ -129,8 +127,7 @@
                 case 0x000a0033:
                     if (methodProcessor.getProtocolVersion().equals(ProtocolVersion.v0_8))
                     {
-                        throw newUnknownMethodException(classId, methodId,
-                                                        methodProcessor.getProtocolVersion());
+                        throw newUnknownMethodException(classId, methodId, methodProcessor.getProtocolVersion());
                     }
                     else
                     {
@@ -144,8 +141,7 @@
                     }
                     else
                     {
-                        throw newUnknownMethodException(classId, methodId,
-                                                        methodProcessor.getProtocolVersion());
+                        throw newUnknownMethodException(classId, methodId, methodProcessor.getProtocolVersion());
                     }
                     break;
                 case 0x000a003d:
@@ -155,8 +151,7 @@
                     }
                     else
                     {
-                        throw newUnknownMethodException(classId, methodId,
-                                                        methodProcessor.getProtocolVersion());
+                        throw newUnknownMethodException(classId, methodId, methodProcessor.getProtocolVersion());
                     }
                     break;
 
@@ -205,7 +200,6 @@
                     ExchangeBoundOkBody.process(in, channelMethodProcessor);
                     break;
 
-
                 // QUEUE_CLASS:
 
                 case 0x0032000b:
@@ -230,7 +224,6 @@
                     }
                     break;
 
-
                 // BASIC_CLASS:
 
                 case 0x003c000b:
@@ -307,8 +300,7 @@
                     break;
 
                 default:
-                    throw newUnknownMethodException(classId, methodId,
-                                                    methodProcessor.getProtocolVersion());
+                    throw newUnknownMethodException(classId, methodId, methodProcessor.getProtocolVersion());
 
             }
         }
@@ -317,5 +309,4 @@
             methodProcessor.setCurrentMethod(0, 0);
         }
     }
-
 }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/EncodingUtilsTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/EncodingUtilsTest.java
index e2d2e78..8fd305f 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/EncodingUtilsTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/EncodingUtilsTest.java
@@ -21,7 +21,7 @@
 package org.apache.qpid.server.protocol.v0_8;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.fail;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -30,7 +30,7 @@
 import org.apache.qpid.server.bytebuffer.QpidByteBuffer;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class EncodingUtilsTest extends UnitTestBase
+class EncodingUtilsTest extends UnitTestBase
 {
     private static final int BUFFER_SIZE = 10;
     private static final int POOL_SIZE = 20;
@@ -39,7 +39,7 @@
     private QpidByteBuffer _buffer;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         QpidByteBuffer.deinitialisePool();
         QpidByteBuffer.initialisePool(BUFFER_SIZE, POOL_SIZE, SPARSITY_FRACTION);
@@ -47,14 +47,14 @@
     }
 
     @AfterEach
-    public void tearDown() throws Exception
+    void tearDown()
     {
         _buffer.dispose();
         QpidByteBuffer.deinitialisePool();
     }
 
     @Test
-    public void testReadLongAsShortStringWhenDigitsAreSpecified() throws Exception
+    void readLongAsShortStringWhenDigitsAreSpecified() throws Exception
     {
         _buffer.putUnsignedByte((short)3);
         _buffer.put((byte)'9');
@@ -65,20 +65,14 @@
     }
 
     @Test
-    public void testReadLongAsShortStringWhenNonDigitCharacterIsSpecified()
+    void readLongAsShortStringWhenNonDigitCharacterIsSpecified()
     {
         _buffer.putUnsignedByte((short)2);
         _buffer.put((byte)'1');
         _buffer.put((byte)'a');
         _buffer.flip();
-        try
-        {
-            EncodingUtils.readLongAsShortString(_buffer);
-            fail("Exception is expected");
-        }
-        catch(AMQFrameDecodingException e)
-        {
-            // pass
-        }
+        assertThrows(AMQFrameDecodingException.class,
+                () -> EncodingUtils.readLongAsShortString(_buffer),
+                "Exception is expected");
     }
 }
\ No newline at end of file
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/FieldTableTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/FieldTableTest.java
index 4255fa3..6298fca 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/FieldTableTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/FieldTableTest.java
@@ -20,17 +20,18 @@
  */
 package org.apache.qpid.server.protocol.v0_8;
 
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
 
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.junit.jupiter.api.Test;
@@ -38,139 +39,137 @@
 import org.apache.qpid.server.bytebuffer.QpidByteBuffer;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class FieldTableTest extends UnitTestBase
+class FieldTableTest extends UnitTestBase
 {
-
     /**
      * Set a boolean and check that we can only get it back as a boolean and a string
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testBoolean()
+    void testBoolean()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", true));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", true));
         assertTrue(table1.containsKey("value"));
         assertEquals(true, table1.get("value"));
     }
 
     /**
      * Set a byte and check that we can only get it back as a byte and a string
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testByte()
+    void testByte()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Byte.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Byte.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Byte.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set a short and check that we can only get it back as a short and a string
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testShort()
+    void testShort()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Short.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Short.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Short.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set a char and check that we can only get it back as a char
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testChar()
+    void testChar()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", 'c'));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", 'c'));
         assertTrue(table1.containsKey("value"));
         assertEquals('c', table1.get("value"));
     }
 
     /**
      * Set a double and check that we can only get it back as a double
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testDouble()
+    void testDouble()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Double.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Double.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Double.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set a float and check that we can only get it back as a float
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testFloat()
+    void testFloat()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Float.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Float.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Float.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set an int and check that we can only get it back as an int
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testInt()
+    void testInt()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Integer.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Integer.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Integer.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set a long and check that we can only get it back as a long
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testLong()
+    void testLong()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", Long.MAX_VALUE));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", Long.MAX_VALUE));
         assertTrue(table1.containsKey("value"));
         assertEquals(Long.MAX_VALUE, table1.get("value"));
     }
 
     /**
      * Set a double and check that we can only get it back as a double
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testBytes()
+    void bytes()
     {
-        byte[] bytes = { 99, 98, 97, 96, 95 };
+        final byte[] bytes = { 99, 98, 97, 96, 95 };
 
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", bytes));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", bytes));
         assertTrue(table1.containsKey("value"));
         assertBytesEqual(bytes, (byte[])table1.get("value"));
     }
 
     /**
      * Set a String and check that we can only get it back as a String
-     * Check that attempting to lookup a non existent value returns null
+     * Check that attempting to look up a non-existent value returns null
      */
     @Test
-    public void testString()
+    void string()
     {
-        FieldTable table1 = FieldTableFactory.createFieldTable(Collections.singletonMap("value", "Hello"));
+        final FieldTable table1 = FieldTableFactory.createFieldTable(Map.of("value", "Hello"));
         assertTrue(table1.containsKey("value"));
-
         assertEquals("Hello", table1.get("value"));
     }
 
     /** Check that a nested field table parameter correctly encodes and decodes to a byte buffer. */
     @Test
-    public void testNestedFieldTable()
+    void nestedFieldTable()
     {
-        byte[] testBytes = new byte[] { 0, 1, 2, 3, 4, 5 };
+        final byte[] testBytes = new byte[] { 0, 1, 2, 3, 4, 5 };
 
-        Map<String, Object> innerTable = new LinkedHashMap<>();
+        final Map<String, Object> innerTable = new LinkedHashMap<>();
 
         // Put some stuff in the inner table.
         innerTable.put("bool", true);
@@ -184,24 +183,24 @@
         innerTable.put("short", Short.MAX_VALUE);
         innerTable.put("string", "hello");
         innerTable.put("null-string", null);
-        innerTable.put("field-array",Arrays.asList("hello", 42, Collections.emptyList()));
+        innerTable.put("field-array", List.of("hello", 42, List.of()));
 
         // Put the inner table in the outer one.
-        FieldTable outerTable = FieldTableFactory.createFieldTable(Collections.singletonMap("innerTable",
-                                                                                         FieldTableFactory.createFieldTable(innerTable)));
+        final FieldTable outerTable = FieldTableFactory
+                .createFieldTable(Map.of("innerTable", FieldTableFactory.createFieldTable(innerTable)));
 
         // Write the outer table into the buffer.
-        QpidByteBuffer buf = QpidByteBuffer.allocate(EncodingUtils.encodedFieldTableLength(outerTable));
+        final QpidByteBuffer buf = QpidByteBuffer.allocate(EncodingUtils.encodedFieldTableLength(outerTable));
 
         outerTable.writeToBuffer(buf);
 
         buf.flip();
 
         // Extract the table back from the buffer again.
-        FieldTable extractedOuterTable = EncodingUtils.readFieldTable(buf);
+        final FieldTable extractedOuterTable = EncodingUtils.readFieldTable(buf);
         assertNotNull(extractedOuterTable, "Unexpected outer table");
 
-        FieldTable extractedTable = (FieldTable)extractedOuterTable.get("innerTable");
+        final FieldTable extractedTable = (FieldTable)extractedOuterTable.get("innerTable");
 
         assertEquals(Boolean.TRUE, extractedTable.get("bool"));
         assertEquals(Byte.MAX_VALUE, extractedTable.get("byte"));
@@ -214,35 +213,32 @@
         assertEquals(Short.MAX_VALUE, extractedTable.get("short"));
         assertEquals("hello", extractedTable.get("string"));
         assertNull(extractedTable.get("null-string"));
-        Collection fieldArray = (Collection) extractedTable.get("field-array");
+        Collection<?> fieldArray = (Collection<?>) extractedTable.get("field-array");
         assertEquals(3, fieldArray.size());
-        Iterator iter = fieldArray.iterator();
+        Iterator<?> iter = fieldArray.iterator();
         assertEquals("hello", iter.next());
         assertEquals(42, iter.next());
-        assertTrue(((Collection)iter.next()).isEmpty());
-    }
-
-    public void testUnsupportedObject()
-    {
-        try
-        {
-            FieldTableFactory.createFieldTable(Collections.singletonMap("value", new Exception()));
-            fail("Non primitive values are not allowed");
-        }
-        catch (AMQPInvalidClassException aice)
-        {
-            assertEquals(AMQPInvalidClassException.INVALID_OBJECT_MSG + Exception.class, aice.getMessage(),
-                    "Non primitive values are not allowed to be set");
-        }
+        assertTrue(((Collection<?>)iter.next()).isEmpty());
     }
 
     @Test
-    public void testValues()
+    void unsupportedObject()
     {
-        Map<String, Object> map = new LinkedHashMap<>();
+        final Map<String, Object> map = Map.of("value", new Exception());
+        final AMQPInvalidClassException thrown = assertThrows(AMQPInvalidClassException.class,
+                () -> FieldTableFactory.createFieldTable(map),
+                "Non primitive values are not allowed");
+        assertEquals(AMQPInvalidClassException.INVALID_OBJECT_MSG + Exception.class, thrown.getMessage(),
+                "Non primitive values are not allowed to be set");
+    }
+
+    @Test
+    void values()
+    {
+        final Map<String, Object> map = new LinkedHashMap<>();
         map.put("bool", true);
         map.put("byte", Byte.MAX_VALUE);
-        byte[] bytes = { 99, 98, 97, 96, 95 };
+        final byte[] bytes = { 99, 98, 97, 96, 95 };
         map.put("bytes", bytes);
         map.put("char", 'c');
         map.put("double", Double.MAX_VALUE);
@@ -263,12 +259,12 @@
         map.put("object-short", Short.MAX_VALUE);
         map.put("object-string", "Hello");
 
-        FieldTable mapTable = FieldTableFactory.createFieldTable(map);
-        QpidByteBuffer buf = QpidByteBuffer.allocate(EncodingUtils.encodedFieldTableLength(mapTable));
+        final FieldTable mapTable = FieldTableFactory.createFieldTable(map);
+        final QpidByteBuffer buf = QpidByteBuffer.allocate(EncodingUtils.encodedFieldTableLength(mapTable));
         mapTable.writeToBuffer(buf);
         buf.flip();
 
-        FieldTable table = EncodingUtils.readFieldTable(buf);
+        final FieldTable table = EncodingUtils.readFieldTable(buf);
         assertNotNull(table);
 
         assertEquals(Boolean.TRUE, table.get("bool"));
@@ -295,11 +291,11 @@
     }
 
     @Test
-    public void testWriteBuffer()
+    void writeBuffer()
     {
-        byte[] bytes = { 99, 98, 97, 96, 95 };
+        final byte[] bytes = { 99, 98, 97, 96, 95 };
 
-        Map<String, Object> map = new LinkedHashMap<>();
+        final Map<String, Object> map = new LinkedHashMap<>();
         map.put("bool", true);
         map.put("byte", Byte.MAX_VALUE);
         map.put("bytes", bytes);
@@ -312,19 +308,18 @@
         map.put("string", "hello");
         map.put("null-string", null);
 
-        FieldTable table = FieldTableFactory.createFieldTable(map);
+        final FieldTable table = FieldTableFactory.createFieldTable(map);
 
-        QpidByteBuffer buf = QpidByteBuffer.allocate((int) table.getEncodedSize() + 4);
+        final QpidByteBuffer buf = QpidByteBuffer.allocate((int) table.getEncodedSize() + 4);
         table.writeToBuffer(buf);
 
         buf.flip();
 
-        long length = buf.getInt() & 0xFFFFFFFFL;
-        QpidByteBuffer bufSlice = buf.slice();
+        final long length = buf.getInt() & 0xFFFFFFFFL;
+        final QpidByteBuffer bufSlice = buf.slice();
         bufSlice.limit((int)length);
 
-
-        FieldTable table2 = FieldTableFactory.createFieldTable(buf);
+        final FieldTable table2 = FieldTableFactory.createFieldTable(buf);
         assertNotNull(table2);
 
         assertEquals(true, table2.get("bool"));
@@ -345,9 +340,9 @@
     }
 
     @Test
-    public void testEncodingSize()
+    void encodingSize()
     {
-        Map<String, Object> result = new LinkedHashMap<>();
+        final Map<String, Object> result = new LinkedHashMap<>();
         int size = 0;
 
         result.put("boolean", true);
@@ -416,136 +411,84 @@
      * Additional test checkPropertyName doesn't accept Null
      */
     @Test
-    public void testCheckPropertyNameIsNull()
+    void checkPropertyNameIsNull()
     {
-        try
-        {
-            FieldTableFactory.createFieldTable(Collections.singletonMap(null, "String"));
-            fail("Null property name is not allowed");
-        }
-        catch (IllegalArgumentException iae)
-        {
-            // normal path
-        }
+        final Map<String, Object> map = Collections.singletonMap(null, "String");
+        assertThrows(IllegalArgumentException.class,
+                () -> FieldTableFactory.createFieldTable(map),
+                "Null property name is not allowed");
     }
 
     /**
      * Additional test checkPropertyName doesn't accept an empty String
      */
     @Test
-    public void testCheckPropertyNameIsEmptyString()
+    void checkPropertyNameIsEmptyString()
     {
-        try
-        {
-            FieldTableFactory.createFieldTable(Collections.singletonMap("", "String"));
-            fail("empty property name is not allowed");
-        }
-        catch (IllegalArgumentException iae)
-        {
-            // normal path
-        }
+        final Map<String, Object> map =Map.of("", "String");
+        assertThrows(IllegalArgumentException.class,
+                () -> FieldTableFactory.createFieldTable(map),
+                "Empty property name is not allowed");
+
     }
 
     /**
      * Additional test checkPropertyName doesn't accept an empty String
      */
     @Test
-    public void testCheckPropertyNameHasMaxLength()
+    void checkPropertyNameHasMaxLength()
     {
-        StringBuilder longPropertyName = new StringBuilder(129);
-
-        for (int i = 0; i < 129; i++)
-        {
-            longPropertyName.append("x");
-        }
-
-        boolean strictAMQP = FieldTable._strictAMQP;
-        try
-        {
-            FieldTable._strictAMQP = true;
-            new FieldTable(Collections.singletonMap(longPropertyName.toString(), "String"));
-            fail("property name must be < 128 characters");
-        }
-        catch (IllegalArgumentException iae)
-        {
-            // normal path
-        }
-        finally
-        {
-            FieldTable._strictAMQP = strictAMQP;
-        }
+        final boolean strictAMQP = FieldTable._strictAMQP;
+        final Map<String, Object> map = Map.of("x".repeat(129), "String");
+        FieldTable._strictAMQP = true;
+        assertThrows(IllegalArgumentException.class,
+                     () -> new FieldTable(map),
+                     "property name must be < 128 characters");
+        FieldTable._strictAMQP = strictAMQP;
     }
 
     /**
      * Additional test checkPropertyName starts with a letter
      */
     @Test
-    public void testCheckPropertyNameStartCharacterIsLetter()
+    void checkPropertyNameStartCharacterIsLetter()
     {
-        boolean strictAMQP = FieldTable._strictAMQP;
+        final boolean strictAMQP = FieldTable._strictAMQP;
 
         // Try a name that starts with a number
-        try
-        {
-            FieldTable._strictAMQP = true;
-            new FieldTable(Collections.singletonMap("1", "String"));
-            fail("property name must start with a letter");
-        }
-        catch (IllegalArgumentException iae)
-        {
-            // normal path
-        }
-        finally
-        {
-            FieldTable._strictAMQP = strictAMQP;
-        }
+        FieldTable._strictAMQP = true;
+        final Map<String, Object> map = Map.of("1", "String");
+        assertThrows(IllegalArgumentException.class,
+                     () -> new FieldTable(map),
+                     "property name must start with a letter");
+        FieldTable._strictAMQP = strictAMQP;
     }
 
     /**
      * Additional test checkPropertyName starts with a hash or a dollar
      */
     @Test
-    public void testCheckPropertyNameStartCharacterIsHashOrDollar()
+    void checkPropertyNameStartCharacterIsHashOrDollar()
     {
-        try
-        {
-            FieldTableFactory.createFieldTable(Collections.singletonMap("#", "String"));
-        }
-        catch (IllegalArgumentException iae)
-        {
-            fail("property name are allowed to start with # and $s");
-        }
-
-        try
-        {
-            FieldTableFactory.createFieldTable(Collections.singletonMap("$", "String"));
-        }
-        catch (IllegalArgumentException iae)
-        {
-            fail("property name are allowed to start with # and $s");
-        }
+        assertDoesNotThrow(() -> FieldTableFactory.createFieldTable(Map.of("#", "String")),
+                "Property names are allowed to start with # and $s");
+        
+        assertDoesNotThrow(() -> FieldTableFactory.createFieldTable(Map.of("$", "String")),
+                "Property names are allowed to start with # and $s");
     }
 
     @Test
-    public void testValidateMalformedFieldTable()
+    void validateMalformedFieldTable()
     {
         final FieldTable fieldTable = buildMalformedFieldTable();
 
-        try
-        {
-            fieldTable.validate();
-            fail("Exception is expected");
-        }
-        catch (RuntimeException e)
-        {
-            // pass
-        }
+        assertThrows(RuntimeException.class, fieldTable::validate, "Exception is expected");
     }
 
     @Test
-    public void testValidateCorrectFieldTable()
+    void validateCorrectFieldTable()
     {
-        final FieldTable ft = new FieldTable(Collections.singletonMap("testKey", "testValue"));
+        final FieldTable ft = new FieldTable(Map.of("testKey", "testValue"));
         final int encodedSize = (int)ft.getEncodedSize() + Integer.BYTES;
         final QpidByteBuffer buf = QpidByteBuffer.allocate(encodedSize);
         ft.writeToBuffer(buf);
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_0_8_to_InternalTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_0_8_to_InternalTest.java
index 1601c68..6777f8b 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_0_8_to_InternalTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_0_8_to_InternalTest.java
@@ -31,7 +31,6 @@
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -56,19 +55,18 @@
 import org.apache.qpid.server.typedmessage.TypedBytesContentWriter;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessageConverter_0_8_to_InternalTest extends UnitTestBase
+@SuppressWarnings({"rawtypes", "uchecked"})
+class MessageConverter_0_8_to_InternalTest extends UnitTestBase
 {
     private final MessageConverter_v0_8_to_Internal _converter = new MessageConverter_v0_8_to_Internal();
-
     private final StoredMessage<MessageMetaData> _handle = mock(StoredMessage.class);
-
     private final MessageMetaData _metaData = mock(MessageMetaData.class);
     private final AMQMessageHeader _header = mock(AMQMessageHeader.class);
     private final ContentHeaderBody _contentHeaderBody = mock(ContentHeaderBody.class);
     private final BasicContentHeaderProperties _basicContentHeaderProperties = mock(BasicContentHeaderProperties.class);
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         when(_handle.getMetaData()).thenReturn(_metaData);
         when(_metaData.getMessageHeader()).thenReturn(_header);
@@ -78,123 +76,121 @@
     }
 
     @Test
-    public void testConvertStringMessageBody()
+    void convertStringMessageBody()
     {
         doTestTextMessage("helloworld", "text/plain");
     }
 
     @Test
-    public void testConvertEmptyStringMessageBody()
+    void convertEmptyStringMessageBody()
     {
         doTestTextMessage(null, "text/plain");
     }
 
     @Test
-    public void testConvertStringXmlMessageBody()
+    void convertStringXmlMessageBody()
     {
         doTestTextMessage("<helloworld></helloworld>", "text/xml");
     }
 
     @Test
-    public void testConvertEmptyStringXmlMessageBody()
+    void convertEmptyStringXmlMessageBody()
     {
         doTestTextMessage(null, "text/xml");
     }
 
     @Test
-    public void testConvertEmptyStringApplicationXmlMessageBody()
+    void convertEmptyStringApplicationXmlMessageBody()
     {
         doTestTextMessage(null, "application/xml");
     }
 
     @Test
-    public void testConvertStringWithContentTypeText()
+    void convertStringWithContentTypeText()
     {
         doTestTextMessage("foo","text/foobar");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationXml()
+    void convertStringWithContentTypeApplicationXml()
     {
         doTestTextMessage("<helloworld></helloworld>","application/xml");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationXmlDtd()
+    void convertStringWithContentTypeApplicationXmlDtd()
     {
         doTestTextMessage("<!DOCTYPE name []>","application/xml-dtd");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationFooXml()
+    void convertStringWithContentTypeApplicationFooXml()
     {
         doTestTextMessage("<helloworld></helloworld>","application/foo+xml");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationJson()
+    void convertStringWithContentTypeApplicationJson()
     {
         doTestTextMessage("[]","application/json");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationFooJson()
+    void convertStringWithContentTypeApplicationFooJson()
     {
         doTestTextMessage("[]","application/foo+json");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationJavascript()
+    void convertStringWithContentTypeApplicationJavascript()
     {
         doTestTextMessage("var foo","application/javascript");
     }
 
     @Test
-    public void testConvertStringWithContentTypeApplicationEcmascript()
+    void convertStringWithContentTypeApplicationEcmascript()
     {
         doTestTextMessage("var foo","application/ecmascript");
     }
 
     @Test
-    public void testConvertBytesMessageBody() throws Exception
+    void convertBytesMessageBody()
     {
         doTestBytesMessage("helloworld".getBytes());
     }
 
     @Test
-    public void testConvertBytesMessageBodyNoContentType()
+    void convertBytesMessageBodyNoContentType()
     {
         final byte[] messageContent = "helloworld".getBytes();
         doTest(messageContent, null, messageContent, null);
     }
 
     @Test
-    public void testConvertMessageBodyUnknownContentType()
+    void convertMessageBodyUnknownContentType()
     {
         final byte[] messageContent = "helloworld".getBytes();
         final String mimeType = "my/bytes";
         doTest(messageContent, mimeType, messageContent, mimeType);
     }
 
-
     @Test
-    public void testConvertEmptyBytesMessageBody() throws Exception
+    void convertEmptyBytesMessageBody()
     {
         doTestBytesMessage(new byte[0]);
     }
 
     @Test
-    public void testConvertJmsStreamMessageBody() throws Exception
+    void convertJmsStreamMessageBody() throws Exception
     {
         final List<Object> expected = Lists.newArrayList("apple", 43, 31.42D);
         final byte[] messageBytes = getJmsStreamMessageBytes(expected);
-
         final String mimeType = "jms/stream-message";
         doTestStreamMessage(messageBytes, mimeType, expected);
     }
 
     @Test
-    public void testConvertEmptyJmsStreamMessageBody()
+    void convertEmptyJmsStreamMessageBody()
     {
         final List<Object> expected = Lists.newArrayList();
         final String mimeType = "jms/stream-message";
@@ -202,7 +198,7 @@
     }
 
     @Test
-    public void testConvertAmqpListMessageBody()
+    void convertAmqpListMessageBody()
     {
         final List<Object> expected = Lists.newArrayList("apple", 43, 31.42D);
         final byte[] messageBytes = new ListToAmqpListConverter().toMimeContent(expected);
@@ -211,107 +207,106 @@
     }
 
     @Test
-    public void testConvertEmptyAmqpListMessageBody()
+    void convertEmptyAmqpListMessageBody()
     {
         final List<Object> expected = Lists.newArrayList();
         doTestStreamMessage(null, "amqp/list", expected);
     }
 
     @Test
-    public void testConvertJmsMapMessageBody() throws Exception
+    void convertJmsMapMessageBody() throws Exception
     {
-        final Map<String, Object> expected = Collections.singletonMap("key", "value");
+        final Map<String, Object> expected = Map.of("key", "value");
         final byte[] messageBytes = getJmsMapMessageBytes(expected);
 
         doTestMapMessage(messageBytes, "jms/map-message", expected);
     }
 
     @Test
-    public void testConvertEmptyJmsMapMessageBody()
+    void convertEmptyJmsMapMessageBody()
     {
-        doTestMapMessage(null, "jms/map-message", Collections.emptyMap());
+        doTestMapMessage(null, "jms/map-message", Map.of());
     }
 
     @Test
-    public void testConvertAmqpMapMessageBody()
+    void convertAmqpMapMessageBody()
     {
-        final Map<String, Object> expected = Collections.singletonMap("key", "value");
+        final Map<String, Object> expected = Map.of("key", "value");
         final byte[] messageBytes = new MapToAmqpMapConverter().toMimeContent(expected);
 
         doTestMapMessage(messageBytes, "amqp/map", expected);
     }
 
     @Test
-    public void testConvertEmptyAmqpMapMessageBody()
+    void convertEmptyAmqpMapMessageBody()
     {
-        doTestMapMessage(null, "amqp/map", Collections.emptyMap());
+        doTestMapMessage(null, "amqp/map", Map.of());
     }
 
     @Test
-    public void testConvertObjectStreamMessageBody() throws Exception
+    void convertObjectStreamMessageBody() throws Exception
     {
         final byte[] messageBytes = getObjectStreamMessageBytes(UUID.randomUUID());
         doTestObjectMessage(messageBytes, "application/java-object-stream", messageBytes);
     }
 
     @Test
-    public void testConvertObjectStream2MessageBody() throws Exception
+    void convertObjectStream2MessageBody() throws Exception
     {
         final byte[] messageBytes = getObjectStreamMessageBytes(UUID.randomUUID());
         doTestObjectMessage(messageBytes, "application/x-java-serialized-object", messageBytes);
     }
 
     @Test
-    public void testConvertEmptyObjectStreamMessageBody()
+    void convertEmptyObjectStreamMessageBody()
     {
         doTestObjectMessage(null, "application/java-object-stream", new byte[0]);
     }
 
     @Test
-    public void testConvertEmptyMessageWithoutContentType()
+    void convertEmptyMessageWithoutContentType()
     {
         doTest(null, null, null, null);
     }
 
     @Test
-    public void testConvertEmptyMessageWithUnknownContentType()
+    void convertEmptyMessageWithUnknownContentType()
     {
         doTest(null, "foo/bar", new byte[0], "foo/bar");
     }
 
     @Test
-    public void testConvertMessageWithoutContentType()
+    void convertMessageWithoutContentType()
     {
         final byte[] expectedContent = "someContent".getBytes(UTF_8);
         doTest(expectedContent, null, expectedContent, null);
     }
 
-
     private byte[] getObjectStreamMessageBytes(final Serializable o) throws Exception
     {
-        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
-             ObjectOutputStream oos = new ObjectOutputStream(bos))
+        try (final ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             final ObjectOutputStream oos = new ObjectOutputStream(bos))
         {
             oos.writeObject(o);
             return bos.toByteArray();
         }
     }
 
-    private byte[] getJmsStreamMessageBytes(List<Object> objects) throws Exception
+    private byte[] getJmsStreamMessageBytes(final List<Object> objects) throws Exception
     {
-        TypedBytesContentWriter writer = new TypedBytesContentWriter();
-        for (Object o : objects)
+        final TypedBytesContentWriter writer = new TypedBytesContentWriter();
+        for (final Object o : objects)
         {
             writer.writeObject(o);
         }
         return getBytes(writer);
     }
 
-    private byte[] getJmsMapMessageBytes(Map<String, Object> map) throws Exception
+    private byte[] getJmsMapMessageBytes(final Map<String, Object> map) throws Exception
     {
-        TypedBytesContentWriter writer = new TypedBytesContentWriter();
+        final TypedBytesContentWriter writer = new TypedBytesContentWriter();
         writer.writeIntImpl(map.size());
-        for (Map.Entry<String, Object> entry : map.entrySet())
+        for (final Map.Entry<String, Object> entry : map.entrySet())
         {
             writer.writeNullTerminatedStringImpl(entry.getKey());
             writer.writeObject(entry.getValue());
@@ -321,7 +316,7 @@
 
     private byte[] getBytes(final TypedBytesContentWriter writer)
     {
-        ByteBuffer buf = writer.getData();
+        final ByteBuffer buf = writer.getData();
         final byte[] expected = new byte[buf.remaining()];
         buf.get(expected);
         return expected;
@@ -348,18 +343,17 @@
             section = new byte[0];
         }
         final QpidByteBuffer combined = QpidByteBuffer.wrap(section);
+
         when(_handle.getContentSize()).thenReturn(section.length);
         final ArgumentCaptor<Integer> offsetCaptor = ArgumentCaptor.forClass(Integer.class);
         final ArgumentCaptor<Integer> sizeCaptor = ArgumentCaptor.forClass(Integer.class);
 
-        when(_handle.getContent(offsetCaptor.capture(),
-                                sizeCaptor.capture())).then(invocation -> combined.view(offsetCaptor.getValue(),
-                                                                                        sizeCaptor.getValue()));
+        when(_handle.getContent(offsetCaptor.capture(), sizeCaptor.capture())).then(invocation ->
+                combined.view(offsetCaptor.getValue(), sizeCaptor.getValue()));
     }
 
     private void doTestTextMessage(final String originalContent, final String mimeType)
     {
-
         final byte[] contentBytes;
         final String expectedContent;
         if (originalContent == null)
@@ -375,7 +369,6 @@
         doTest(contentBytes, mimeType, expectedContent, mimeType);
     }
 
-
     private void doTestMapMessage(final byte[] messageBytes,
                                   final String mimeType,
                                   final Map<String, Object> expected)
@@ -383,7 +376,7 @@
         doTest(messageBytes, mimeType, expected, null);
     }
 
-    private void doTestBytesMessage(final byte[] messageContent) throws Exception
+    private void doTestBytesMessage(final byte[] messageContent)
     {
         doTest(messageContent,"application/octet-stream", messageContent, "application/octet-stream");
     }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_Internal_to_0_8Test.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_Internal_to_0_8Test.java
index 2918b5a..2c832c6 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_Internal_to_0_8Test.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageConverter_Internal_to_0_8Test.java
@@ -30,8 +30,8 @@
 import java.io.ObjectOutputStream;
 import java.io.Serializable;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
+import java.util.Map;
 
 import com.google.common.collect.Lists;
 import com.google.common.io.ByteStreams;
@@ -54,97 +54,97 @@
 import org.apache.qpid.server.typedmessage.mimecontentconverter.MapToJmsMapMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessageConverter_Internal_to_0_8Test extends UnitTestBase
+class MessageConverter_Internal_to_0_8Test extends UnitTestBase
 {
     private final MessageConverter_Internal_to_v0_8 _converter = new MessageConverter_Internal_to_v0_8();
     private final StoredMessage<InternalMessageMetaData> _handle = mock(StoredMessage.class);
     private final AMQMessageHeader _amqpHeader = mock(AMQMessageHeader.class);
 
     @Test
-    public void testStringMessage() throws Exception
+    void stringMessage() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         final String mimeType = "text/plain";
         doTest(content, mimeType, content.getBytes(UTF_8), mimeType);
     }
 
     @Test
-    public void testStringMessageWithUnknownMimeType() throws Exception
+    void stringMessageWithUnknownMimeType() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         final String mimeType = "foo/bar";
         doTest(content, mimeType, content.getBytes(UTF_8), "text/plain");
     }
 
     @Test
-    public void testStringMessageWithoutMimeType() throws Exception
+    void stringMessageWithoutMimeType() throws Exception
     {
-        String content = "testContent";
+        final String content = "testContent";
         doTest(content, null, content.getBytes(UTF_8), "text/plain");
     }
 
     @Test
-    public void testListMessageWithMimeType() throws Exception
+    void listMessageWithMimeType() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
         final ListToJmsStreamMessage listToJmsStreamMessage = new ListToJmsStreamMessage();
         final byte[] expectedContent = listToJmsStreamMessage.toMimeContent(content);
         doTest(content, "foo/bar", expectedContent, listToJmsStreamMessage.getMimeType());
     }
 
     @Test
-    public void testListMessageWithoutMimeType() throws Exception
+    void listMessageWithoutMimeType() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42);
         final ListToJmsStreamMessage listToJmsStreamMessage = new ListToJmsStreamMessage();
         final byte[] expectedContent = listToJmsStreamMessage.toMimeContent(content);
         doTest(content, null, expectedContent, listToJmsStreamMessage.getMimeType());
     }
 
     @Test
-    public void testListMessageWithoutMimeTypeWithNonJmsContent() throws Exception
+    void listMessageWithoutMimeTypeWithNonJmsContent() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42, Lists.newArrayList());
+        final ArrayList<?> content = Lists.newArrayList("testItem", 37.5, 42, Lists.newArrayList());
         final ListToAmqpListConverter listToAmqpListConverter = new ListToAmqpListConverter();
         final byte[] expectedContent = listToAmqpListConverter.toMimeContent(content);
         doTest(content, null, expectedContent, listToAmqpListConverter.getMimeType());
     }
 
     @Test
-    public void testListMessageWithoutMimeTypeWithNonConvertibleItem() throws Exception
+    void listMessageWithoutMimeTypeWithNonConvertibleItem() throws Exception
     {
-        ArrayList<?> content = Lists.newArrayList(new MySerializable());
+        final ArrayList<?> content = Lists.newArrayList(new MySerializable());
         final InternalMessage sourceMessage = getAmqMessage(content, null);
         doTest(content, null, getObjectStreamMessageBytes(content), "application/java-object-stream");
     }
 
     @Test
-    public void testByteArrayMessageWithoutMimeType() throws Exception
+    void byteArrayMessageWithoutMimeType() throws Exception
     {
-        byte[] content = "testContent".getBytes(UTF_8);
+        final byte[] content = "testContent".getBytes(UTF_8);
         doTest(content, null, content, "application/octet-stream");
     }
 
     @Test
-    public void testByteArrayMessageWithMimeType() throws Exception
+    void byteArrayMessageWithMimeType() throws Exception
     {
-        byte[] content = "testContent".getBytes(UTF_8);
+        final byte[] content = "testContent".getBytes(UTF_8);
         final String mimeType = "foo/bar";
         doTest(content, mimeType, content, mimeType);
     }
 
     @Test
-    public void testEmptyByteArrayMessageWithMimeType() throws Exception
+    void emptyByteArrayMessageWithMimeType() throws Exception
     {
-        byte[] content = new byte[0];
+        final byte[] content = new byte[0];
         final String mimeType = "foo/bar";
         doTest(content, mimeType, content, mimeType);
     }
 
     @Test
-    public void testMapMessageWithMimeType() throws Exception
+    void mapMessageWithMimeType() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
+        final HashMap<Object, Object> content = new HashMap<>();
         content.put("key1", 37);
         content.put("key2", "foo");
         final String mimeType = "foo/bar";
@@ -154,9 +154,9 @@
     }
 
     @Test
-    public void testMapMessageWithoutMimeType() throws Exception
+    void mapMessageWithoutMimeType() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
+        final HashMap<Object, Object> content = new HashMap<>();
         content.put("key1", 37);
         content.put("key2", "foo");
         final MapToJmsMapMessage mapToJmsMapMessage = new MapToJmsMapMessage();
@@ -165,10 +165,10 @@
     }
 
     @Test
-    public void testMapMessageWithMimeTypeWithNonJmsContent() throws Exception
+    void mapMessageWithMimeTypeWithNonJmsContent() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
-        content.put("key", Collections.singletonMap("foo", "bar"));
+        final HashMap<Object, Object> content = new HashMap<>();
+        content.put("key", Map.of("foo", "bar"));
         final String mimeType = "foo/bar";
         final MapToAmqpMapConverter mapToAmqpMapConverter = new MapToAmqpMapConverter();
         final byte[] expectedContent = mapToAmqpMapConverter.toMimeContent(content);
@@ -176,47 +176,45 @@
     }
 
     @Test
-    public void testMapMessageWithoutMimeTypeWithNonConvertibleEntry() throws Exception
+    void mapMessageWithoutMimeTypeWithNonConvertibleEntry() throws Exception
     {
-        HashMap<Object, Object> content = new HashMap<>();
+        final HashMap<Object, Object> content = new HashMap<>();
         content.put(37, new MySerializable());
 
         doTest(content, null, getObjectStreamMessageBytes(content), "application/java-object-stream");
     }
 
     @Test
-    public void testSerializableMessageWithMimeType() throws Exception
+    void serializableMessageWithMimeType() throws Exception
     {
-        Serializable content = new MySerializable();
+        final Serializable content = new MySerializable();
         final String mimeType = "foo/bar";
         doTest(content, mimeType, getObjectStreamMessageBytes(content), "application/java-object-stream");
     }
 
     @Test
-    public void testSerializableMessageWithoutMimeType() throws Exception
+    void serializableMessageWithoutMimeType() throws Exception
     {
-        Serializable content = new MySerializable();
+        final Serializable content = new MySerializable();
         doTest(content, null, getObjectStreamMessageBytes(content), "application/java-object-stream");
     }
 
     @Test
-    public void testNullMessageWithoutMimeType() throws Exception
+    void nullMessageWithoutMimeType() throws Exception
     {
         doTest(null, null, null, null);
     }
 
-
     private byte[] getObjectStreamMessageBytes(final Serializable o) throws Exception
     {
-        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
-             ObjectOutputStream oos = new ObjectOutputStream(bos))
+        try (final ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             final ObjectOutputStream oos = new ObjectOutputStream(bos))
         {
             oos.writeObject(o);
             return bos.toByteArray();
         }
     }
 
-
     protected InternalMessage getAmqMessage(final Serializable content, final String mimeType) throws Exception
     {
         final byte[] serializedContent = getObjectStreamMessageBytes(content);
@@ -248,9 +246,8 @@
         final ArgumentCaptor<Integer> offsetCaptor = ArgumentCaptor.forClass(Integer.class);
         final ArgumentCaptor<Integer> sizeCaptor = ArgumentCaptor.forClass(Integer.class);
 
-        when(_handle.getContent(offsetCaptor.capture(),
-                                sizeCaptor.capture())).then(invocation -> combined.view(offsetCaptor.getValue(),
-                                                                                        sizeCaptor.getValue()));
+        when(_handle.getContent(offsetCaptor.capture(), sizeCaptor.capture())).then(invocation ->
+                combined.view(offsetCaptor.getValue(), sizeCaptor.getValue()));
     }
 
     private void doTest(final Serializable messageBytes,
@@ -268,8 +265,8 @@
 
     private byte[] getBytes(final QpidByteBuffer content) throws Exception
     {
-        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
-             InputStream contentInputStream = content.asInputStream())
+        try (final ByteArrayOutputStream bos = new ByteArrayOutputStream();
+             final InputStream contentInputStream = content.asInputStream())
         {
             ByteStreams.copy(contentInputStream, bos);
             content.dispose();
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageMetaDataFactoryTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageMetaDataFactoryTest.java
index 665d650..543be7b 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageMetaDataFactoryTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/MessageMetaDataFactoryTest.java
@@ -32,22 +32,24 @@
 import org.apache.qpid.server.protocol.v0_8.transport.MessagePublishInfo;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessageMetaDataFactoryTest extends UnitTestBase
+class MessageMetaDataFactoryTest extends UnitTestBase
 {
     private static final String CONTENT_TYPE = "content/type";
+
     private final long _arrivalTime = System.currentTimeMillis();
     private final AMQShortString _routingKey = AMQShortString.valueOf("routingkey");
     private final AMQShortString _exchange = AMQShortString.valueOf("exch");
+
     private MessageMetaData _mmd;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _mmd = createTestMessageMetaData();
     }
 
     @AfterEach
-    public void tearDown() throws Exception
+    void tearDown()
     {
         if (_mmd != null)
         {
@@ -56,14 +58,14 @@
     }
 
     @Test
-    public void testUnmarshalFromSingleBuffer()
+    void unmarshalFromSingleBuffer()
     {
-        try(QpidByteBuffer qpidByteBuffer = QpidByteBuffer.allocateDirect(_mmd.getStorableSize()))
+        try (final QpidByteBuffer qpidByteBuffer = QpidByteBuffer.allocateDirect(_mmd.getStorableSize()))
         {
             _mmd.writeToBuffer(qpidByteBuffer);
             qpidByteBuffer.flip();
 
-            MessageMetaData recreated = MessageMetaData.FACTORY.createMetaData(qpidByteBuffer);
+            final MessageMetaData recreated = MessageMetaData.FACTORY.createMetaData(qpidByteBuffer);
 
             assertEquals(_arrivalTime, recreated.getArrivalTime(), "Unexpected arrival time");
             assertEquals(_routingKey, recreated.getMessagePublishInfo().getRoutingKey(), "Unexpected routing key");
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManagerTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManagerTest.java
index bad539b..949d6fc 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManagerTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/Pre0_10CreditManagerTest.java
@@ -21,26 +21,17 @@
 
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.Mockito.mock;
 
-import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import org.apache.qpid.server.transport.ProtocolEngine;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class Pre0_10CreditManagerTest extends UnitTestBase
+class Pre0_10CreditManagerTest extends UnitTestBase
 {
     private Pre0_10CreditManager _creditManager;
 
-    @BeforeEach
-    public void setUp() throws Exception
-    {
-        ProtocolEngine protocolEngine = mock(ProtocolEngine.class);
-    }
-
     @Test
-    public void testBasicMessageCredit()
+    void basicMessageCredit()
     {
         _creditManager = new Pre0_10CreditManager(0, 0, 100L, 10L);
         _creditManager.setCreditLimits(0, 2);
@@ -56,7 +47,7 @@
     }
 
     @Test
-    public void testBytesLimitDoesNotPreventLargeMessage()
+    void bytesLimitDoesNotPreventLargeMessage()
     {
         _creditManager = new Pre0_10CreditManager(0, 0, 100L, 10L);
         _creditManager.setCreditLimits(10, 0);
@@ -67,7 +58,7 @@
     }
 
     @Test
-    public void testUseCreditWithNegativeMessageCredit()
+    void useCreditWithNegativeMessageCredit()
     {
         _creditManager = new Pre0_10CreditManager(0, 0, 100L, 10L);
         _creditManager.setCreditLimits(0, 3);
@@ -86,7 +77,7 @@
     }
 
     @Test
-    public void testUseCreditWithNegativeBytesCredit()
+    void useCreditWithNegativeBytesCredit()
     {
         _creditManager = new Pre0_10CreditManager(0, 0, 100L, 10L);
         _creditManager.setCreditLimits(3, 0);
@@ -105,7 +96,7 @@
     }
 
     @Test
-    public void testCreditAccountingWhileMessageLimitNotSet()
+    void creditAccountingWhileMessageLimitNotSet()
     {
         _creditManager = new Pre0_10CreditManager(0, 0, 100L, 10L);
         assertTrue(_creditManager.useCreditForMessage(37), "Creditmanager should be able to useCredit");
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_Internal_to_v0_8Test.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_Internal_to_v0_8Test.java
index 453d82f..7ec2c6c 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_Internal_to_v0_8Test.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_Internal_to_v0_8Test.java
@@ -24,8 +24,8 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
 import static org.mockito.AdditionalAnswers.returnsFirstArg;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
@@ -36,7 +36,6 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -58,13 +57,13 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class PropertyConverter_Internal_to_v0_8Test extends UnitTestBase
+class PropertyConverter_Internal_to_v0_8Test extends UnitTestBase
 {
     private MessageConverter_Internal_to_v0_8 _messageConverter;
     private NamedAddressSpace _addressSpace;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _messageConverter = new MessageConverter_Internal_to_v0_8();
         _addressSpace = mock(NamedAddressSpace.class);
@@ -72,12 +71,12 @@
     }
 
     @Test
-    public void testDurableTrueConversion()
+    void durableTrueConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
-        InternalMessage originalMessage = createTestMessage(header, null, true);
+        final InternalMessage originalMessage = createTestMessage(header, null, true);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(BasicContentHeaderProperties.PERSISTENT,
                 (long) convertedMessage.getContentHeaderBody().getProperties().getDeliveryMode(),
@@ -89,12 +88,12 @@
     }
 
     @Test
-    public void testDurableFalseConversion()
+    void durableFalseConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
-        InternalMessage originalMessage = createTestMessage(header, null, false);
+        final InternalMessage originalMessage = createTestMessage(header, null, false);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(BasicContentHeaderProperties.NON_PERSISTENT,
                 (long) convertedMessage.getContentHeaderBody().getProperties().getDeliveryMode(),
@@ -105,43 +104,43 @@
     }
 
     @Test
-    public void testPriorityConversion()
+    void priorityConversion()
     {
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
-        byte priority = (byte) 7;
+        final byte priority = (byte) 7;
         when(header.getPriority()).thenReturn(priority);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(priority, (long) convertedMessage.getContentHeaderBody().getProperties().getPriority(),
                 "Unexpected priority");
     }
 
     @Test
-    public void testExpirationConversion()
+    void expirationConversion()
     {
-        long ttl = 10000;
-        long expiryTime = System.currentTimeMillis() + ttl;
+        final long ttl = 10000;
+        final long expiryTime = System.currentTimeMillis() + ttl;
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getExpiration()).thenReturn(expiryTime);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(expiryTime, convertedMessage.getContentHeaderBody().getProperties().getExpiration(),
                 "Unexpected expiration time");
     }
 
     @Test
-    public void testContentEncodingConversion()
+    void contentEncodingConversion()
     {
-        String contentEncoding = "my-test-encoding";
+        final String contentEncoding = "my-test-encoding";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getEncoding()).thenReturn(contentEncoding);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(contentEncoding, convertedMessage.getContentHeaderBody().getProperties().getEncodingAsString(),
                 "Unexpected content encoding");
@@ -149,170 +148,150 @@
     }
 
     @Test
-    public void testLongContentEncodingConversion()
+    void longContentEncodingConversion()
     {
-        String contentEncoding = generateLongString();
+        final String contentEncoding = generateLongString();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getEncoding()).thenReturn(contentEncoding);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        try
-        {
-            _messageConverter.convert(originalMessage, _addressSpace);
-            fail("Expected exception is not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(originalMessage, _addressSpace),
+                "Expected exception is not thrown");
     }
 
     @Test
-    public void testMessageIdConversion()
+    void messageIdConversion()
     {
         final String messageId = "testMessageId";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getMessageId()).thenReturn(messageId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(messageId, convertedMessage.getContentHeaderBody().getProperties().getMessageIdAsString(),
                 "Unexpected messageId");
     }
 
     @Test
-    public void testMessageIdConversionWhenLengthExceeds255()
+    void messageIdConversionWhenLengthExceeds255()
     {
         final String messageId = generateLongString();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getMessageId()).thenReturn(messageId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertNull(convertedMessage.getContentHeaderBody().getProperties().getMessageId(), "Unexpected messageId");
-
     }
 
     @Test
-    public void testCorrelationIdConversionWhenLengthExceeds255()
+    void correlationIdConversionWhenLengthExceeds255()
     {
         final String correlationId = generateLongString();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getCorrelationId()).thenReturn(correlationId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        try
-        {
-            _messageConverter.convert(originalMessage, _addressSpace);
-            fail("Expected exception is not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(originalMessage, _addressSpace),
+                "Expected exception is not thrown");
     }
 
     @Test
-    public void testUserIdConversion()
+    void userIdConversion()
     {
         final String userId = "testUserId";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getUserId()).thenReturn(userId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(userId, convertedMessage.getContentHeaderBody().getProperties().getUserIdAsString(),
                 "Unexpected userId");
     }
 
     @Test
-    public void testUserIdConversionWhenLengthExceeds255()
+    void userIdConversionWhenLengthExceeds255()
     {
         final String userId = generateLongString();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getUserId()).thenReturn(userId);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertNull(convertedMessage.getContentHeaderBody().getProperties().getUserId(), "Unexpected userId");
     }
 
     @Test
-    public void testTimestampConversion()
+    void timestampConversion()
     {
         final long timestamp = System.currentTimeMillis();
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getTimestamp()).thenReturn(timestamp);
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(timestamp, convertedMessage.getContentHeaderBody().getProperties().getTimestamp(),
                 "Unexpected timestamp");
     }
 
     @Test
-    public void testHeadersConversion()
+    void headersConversion()
     {
-        final Map<String, Object> properties = new HashMap<>();
-        properties.put("testProperty1", "testProperty1Value");
-        properties.put("intProperty", 1);
+        final Map<String, Object> properties = Map.of("testProperty1", "testProperty1Value",
+                "intProperty", 1);
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getHeaderNames()).thenReturn(properties.keySet());
         doAnswer(invocation ->
-                 {
-                     final String originalArgument = (String) (invocation.getArguments())[0];
-                     return properties.get(originalArgument);
-                 }).when(header).getHeader(any(String.class));
-        InternalMessage originalMessage = createTestMessage(header);
+        {
+            final String originalArgument = (String) (invocation.getArguments())[0];
+            return properties.get(originalArgument);
+        }).when(header).getHeader(any(String.class));
+        final InternalMessage originalMessage = createTestMessage(header);
 
         final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
-        Map<String, Object> convertedHeaders = convertedMessage.getContentHeaderBody().getProperties().getHeadersAsMap();
+        final Map<String, Object> convertedHeaders = convertedMessage.getContentHeaderBody().getProperties().getHeadersAsMap();
         assertEquals(properties, new HashMap<>(convertedHeaders), "Unexpected application properties");
     }
 
     @Test
-    public void testHeadersConversionWhenKeyLengthExceeds255()
+    void headersConversionWhenKeyLengthExceeds255()
     {
-        final Map<String, Object> properties = Collections.singletonMap(generateLongString(), "test");
+        final Map<String, Object> properties = Map.of(generateLongString(), "test");
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getHeaderNames()).thenReturn(properties.keySet());
         doAnswer(invocation ->
-                 {
-                     final String originalArgument = (String) (invocation.getArguments())[0];
-                     return properties.get(originalArgument);
-                 }).when(header).getHeader(any(String.class));
-        InternalMessage originalMessage = createTestMessage(header);
+        {
+            final String originalArgument = (String) (invocation.getArguments())[0];
+            return properties.get(originalArgument);
+        }).when(header).getHeader(any(String.class));
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        try
-        {
-            _messageConverter.convert(originalMessage, _addressSpace);
-            fail("Expected exception not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(originalMessage, _addressSpace),
+                "Expected exception not thrown");
     }
 
     @Test
-    public void testReplyToConversionWhenQueueIsSpecified()
+    void replyToConversionWhenQueueIsSpecified()
     {
         final String replyTo = "testQueue";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getReplyTo()).thenReturn(replyTo);
-        Queue queue = mock(Queue.class);
+        final Queue<?> queue = mock(Queue.class);
         when(queue.getName()).thenReturn(replyTo);
         doReturn(queue).when(_addressSpace).getAttainedMessageDestination(eq(replyTo), anyBoolean());
 
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals("direct:////" + replyTo,
                 convertedMessage.getContentHeaderBody().getProperties().getReplyToAsString(),
@@ -320,20 +299,20 @@
     }
 
     @Test
-    public void testReplyToConversionWhenExchangeIsSpecified()
+    void replyToConversionWhenExchangeIsSpecified()
     {
         final String replyTo = "testExchange";
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getReplyTo()).thenReturn(replyTo);
-        Exchange exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.getName()).thenReturn(replyTo);
         when(exchange.getType()).thenReturn(ExchangeDefaults.FANOUT_EXCHANGE_CLASS);
 
         doReturn(exchange).when(_addressSpace).getAttainedMessageDestination(eq(replyTo), anyBoolean());
 
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals("fanout://" + replyTo + "//",
                 convertedMessage.getContentHeaderBody().getProperties().getReplyToAsString(),
@@ -341,22 +320,22 @@
     }
 
     @Test
-    public void testReplyToConversionWhenExchangeAndRoutingKeyAreSpecified()
+    void replyToConversionWhenExchangeAndRoutingKeyAreSpecified()
     {
         final String exchangeName = "testExchange";
         final String routingKey = "testKey";
         final String replyTo = String.format("%s/%s", exchangeName, routingKey);
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getReplyTo()).thenReturn(replyTo);
-        Exchange exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.getName()).thenReturn(exchangeName);
         when(exchange.getType()).thenReturn(ExchangeDefaults.TOPIC_EXCHANGE_CLASS);
 
         doReturn(exchange).when(_addressSpace).getAttainedMessageDestination(eq(exchangeName), anyBoolean());
 
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals("topic://" + exchangeName + "//?routingkey='" + routingKey + "'",
                 convertedMessage.getContentHeaderBody().getProperties().getReplyToAsString(),
@@ -364,7 +343,7 @@
     }
 
     @Test
-    public void testReplyToConversionWhenNonExistingExchangeAndRoutingKeyAreSpecified()
+    void replyToConversionWhenNonExistingExchangeAndRoutingKeyAreSpecified()
     {
         final String exchangeName = "testExchange";
         final String routingKey = "testKey";
@@ -372,9 +351,9 @@
         final AMQMessageHeader header = mock(AMQMessageHeader.class);
         when(header.getReplyTo()).thenReturn(replyTo);
 
-        InternalMessage originalMessage = createTestMessage(header);
+        final InternalMessage originalMessage = createTestMessage(header);
 
-        AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final AMQMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals("direct:////?routingkey='" + replyTo + "'",
                 convertedMessage.getContentHeaderBody().getProperties().getReplyToAsString(),
@@ -382,16 +361,16 @@
     }
 
     @Test
-    public void testToConversionWhenExchangeAndRoutingKeyIsSpecified()
+    void toConversionWhenExchangeAndRoutingKeyIsSpecified()
     {
         final String testExchange = "testExchange";
         final String testRoutingKey = "testRoutingKey";
 
-        String to = testExchange + "/" + testRoutingKey;
+        final String to = testExchange + "/" + testRoutingKey;
 
-        InternalMessage message = createTestMessage(to);
+        final InternalMessage message = createTestMessage(to);
 
-        Exchange<?> exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.getName()).thenReturn(testExchange);
         doReturn(exchange).when(_addressSpace).getAttainedMessageDestination(eq(testExchange), anyBoolean());
 
@@ -405,12 +384,12 @@
     }
 
     @Test
-    public void testToConversionWhenExchangeIsSpecified()
+    void toConversionWhenExchangeIsSpecified()
     {
         final String testExchange = "testExchange";
-        InternalMessage message = createTestMessage(testExchange);
+        final InternalMessage message = createTestMessage(testExchange);
 
-        final Exchange exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.getName()).thenReturn(testExchange);
         doReturn(exchange).when(_addressSpace).getAttainedMessageDestination(eq(testExchange), anyBoolean());
 
@@ -423,16 +402,16 @@
     }
 
     @Test
-    public void testConversionWhenToIsUnsetButInitialRoutingKeyIsSet()
+    void conversionWhenToIsUnsetButInitialRoutingKeyIsSet()
     {
         final String testExchange = "testExchange";
         final String testRoutingKey = "testRoutingKey";
 
-        InternalMessage message = createTestMessage("");
+        final InternalMessage message = createTestMessage("");
         final String testInitialRoutingAddress = testExchange + "/" + testRoutingKey;
         message.setInitialRoutingAddress(testInitialRoutingAddress);
 
-        final Exchange exchange = mock(Exchange.class);
+        final Exchange<?> exchange = mock(Exchange.class);
         when(exchange.getName()).thenReturn(testExchange);
         doReturn(exchange).when(_addressSpace).getAttainedMessageDestination(eq(testExchange), anyBoolean());
 
@@ -445,12 +424,12 @@
     }
 
     @Test
-    public void testToConversionWhenQueueIsSpecified()
+    void toConversionWhenQueueIsSpecified()
     {
         final String testQueue = "testQueue";
-        InternalMessage message = createTestMessage(testQueue);
+        final InternalMessage message = createTestMessage(testQueue);
 
-        final Queue queue = mock(Queue.class);
+        final Queue<?> queue = mock(Queue.class);
         when(queue.getName()).thenReturn(testQueue);
         doReturn(queue).when(_addressSpace).getAttainedMessageDestination(eq(testQueue), anyBoolean());
 
@@ -463,15 +442,15 @@
     }
 
     @Test
-    public void testToConversionWhenGlobalAddressIsUnknown()
+    void toConversionWhenGlobalAddressIsUnknown()
     {
         final String globalPrefix = "/testPrefix";
         final String queueName = "testQueue";
         final String globalAddress = globalPrefix + "/" + queueName;
 
-        InternalMessage message = createTestMessage(globalAddress);
+        final InternalMessage message = createTestMessage(globalAddress);
 
-        Queue<?> queue = mock(Queue.class);
+        final Queue<?> queue = mock(Queue.class);
         when(queue.getName()).thenReturn(queueName);
         doReturn(queue).when(_addressSpace).getAttainedMessageDestination(eq(queueName), anyBoolean());
 
@@ -484,15 +463,15 @@
     }
 
     @Test
-    public void testToConversionWhenGlobalAddressIsKnown()
+    void toConversionWhenGlobalAddressIsKnown()
     {
         final String globalPrefix = "/testPrefix";
         final String queueName = "testQueue";
         final String globalAddress = globalPrefix + "/" + queueName;
 
-        InternalMessage message = createTestMessage(globalAddress);
+        final InternalMessage message = createTestMessage(globalAddress);
 
-        Queue<?> queue = mock(Queue.class);
+        final Queue<?> queue = mock(Queue.class);
         when(queue.getName()).thenReturn(queueName);
         doReturn(queue).when(_addressSpace).getAttainedMessageDestination(eq(queueName), anyBoolean());
         when(_addressSpace.getLocalAddress(globalAddress)).thenReturn(queueName);
@@ -506,53 +485,41 @@
     }
 
     @Test
-    public void testToConversionWhenExchangeLengthExceeds255()
+    void toConversionWhenExchangeLengthExceeds255()
     {
         final String testExchange = generateLongString();
         final String testRoutingKey = "testRoutingKey";
 
-        String to = testExchange + "/" + testRoutingKey;
+        final String to = testExchange + "/" + testRoutingKey;
 
-        InternalMessage message = createTestMessage(to);
+        final InternalMessage message = createTestMessage(to);
 
-        try
-        {
-            _messageConverter.convert(message, _addressSpace);
-            fail("Exception is not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(message, _addressSpace),
+                "Exception is not thrown");
     }
 
     @Test
-    public void testToConversionWhenRoutingKeyLengthExceeds255()
+    void toConversionWhenRoutingKeyLengthExceeds255()
     {
         final String testExchange = "testExchange";
         final String testRoutingKey = generateLongString();
 
-        String to = testExchange + "/" + testRoutingKey;
+        final String to = testExchange + "/" + testRoutingKey;
 
-        InternalMessage message = createTestMessage(to);
+        final InternalMessage message = createTestMessage(to);
 
-        try
-        {
-            _messageConverter.convert(message, _addressSpace);
-            fail("Exception is not thrown");
-        }
-        catch (MessageConversionException e)
-        {
-            // pass
-        }
+        assertThrows(MessageConversionException.class,
+                () -> _messageConverter.convert(message, _addressSpace),
+                "Exception is not thrown");
     }
 
     @Test
-    public void testToConversionWhenDestinationIsSpecifiedButDoesNotExists()
+    void toConversionWhenDestinationIsSpecifiedButDoesNotExists()
     {
         final String testDestination = "testDestination";
 
-        InternalMessage message = createTestMessage(testDestination);
+        final InternalMessage message = createTestMessage(testDestination);
 
         final AMQMessage convertedMessage = _messageConverter.convert(message, _addressSpace);
 
@@ -568,7 +535,7 @@
     }
 
     private InternalMessage createTestMessage(final AMQMessageHeader header,
-                                              byte[] content,
+                                              final byte[] content,
                                               final boolean persistent)
     {
         final InternalMessageHeader internalMessageHeader = new InternalMessageHeader(header);
@@ -591,7 +558,7 @@
         return storedMessage;
     }
 
-    private InternalMessage createTestMessage(String to)
+    private InternalMessage createTestMessage(final String to)
     {
         final InternalMessageHeader internalMessageHeader = new InternalMessageHeader(mock(AMQMessageHeader.class));
         final StoredMessage<InternalMessageMetaData> handle =
@@ -606,12 +573,6 @@
 
     private String generateLongString(int stringLength)
     {
-        StringBuilder buffer = new StringBuilder();
-        for (int i = 0; i < stringLength; i++)
-        {
-            buffer.append('x');
-        }
-
-        return buffer.toString();
+        return "x".repeat(Math.max(0, stringLength));
     }
 }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_v0_8_to_InternalTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_v0_8_to_InternalTest.java
index ed7cd18..b30d738 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_v0_8_to_InternalTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/PropertyConverter_v0_8_to_InternalTest.java
@@ -42,26 +42,26 @@
 import org.apache.qpid.server.store.StoredMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class PropertyConverter_v0_8_to_InternalTest extends UnitTestBase
+class PropertyConverter_v0_8_to_InternalTest extends UnitTestBase
 {
     private MessageConverter_v0_8_to_Internal _messageConverter;
     private NamedAddressSpace _addressSpace;
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _messageConverter = new MessageConverter_v0_8_to_Internal();
         _addressSpace = mock(NamedAddressSpace.class);
     }
 
     @Test
-    public void testDeliveryModePersistentConversion()
+    void deliveryModePersistentConversion()
     {
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setDeliveryMode(BasicContentHeaderProperties.PERSISTENT);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertTrue(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertTrue(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -69,13 +69,13 @@
     }
 
     @Test
-    public void testDeliveryModeNonPersistentConversion()
+    void deliveryModeNonPersistentConversion()
     {
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setDeliveryMode(BasicContentHeaderProperties.NON_PERSISTENT);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertFalse(convertedMessage.isPersistent(), "Unexpected persistence of message");
         assertFalse(convertedMessage.getStoredMessage().getMetaData().isPersistent(),
@@ -83,165 +83,163 @@
     }
 
     @Test
-    public void testPriorityConversion()
+    void priorityConversion()
     {
-        byte priority = (byte) 7;
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final byte priority = (byte) 7;
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setPriority(priority);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(priority, (long) convertedMessage.getMessageHeader().getPriority(), "Unexpected priority");
-
     }
 
     @Test
-    public void testExpirationConversion()
+    void expirationConversion()
     {
-        long ttl = 10000;
-        long arrivalTime = System.currentTimeMillis();
-        long expiryTime = arrivalTime + ttl;
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final long ttl = 10000;
+        final long arrivalTime = System.currentTimeMillis();
+        final long expiryTime = arrivalTime + ttl;
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setExpiration(expiryTime);
         final AMQMessage originalMessage = createTestMessage(header, arrivalTime);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(expiryTime, convertedMessage.getMessageHeader().getExpiration(), "Unexpected expiration");
     }
 
     @Test
-    public void testContentEncodingConversion()
+    void contentEncodingConversion()
     {
-        String contentEncoding = "my-test-encoding";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final String contentEncoding = "my-test-encoding";
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setEncoding(contentEncoding);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(contentEncoding, convertedMessage.getMessageHeader().getEncoding(), "Unexpected content encoding");
 
     }
 
     @Test
-    public void testMessageIdConversion()
+    void messageIdConversion()
     {
         final String messageId = "testMessageId";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setMessageId(messageId);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(messageId, convertedMessage.getMessageHeader().getMessageId(), "Unexpected messageId");
     }
 
     @Test
-    public void testCorrelationIdStringConversion()
+    void correlationIdStringConversion()
     {
         final String correlationId = "testMessageCorrelationId";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setCorrelationId(correlationId);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(correlationId, convertedMessage.getMessageHeader().getCorrelationId(), "Unexpected correlationId");
     }
 
     @Test
-    public void testUserIdConversion()
+    void userIdConversion()
     {
         final String userId = "testUserId";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setUserId(userId);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(userId, convertedMessage.getMessageHeader().getUserId(), "Unexpected userId");
     }
 
     @Test
-    public void testReplyToConversionForDirectExchangeAndRoutingKey()
+    void replyToConversionForDirectExchangeAndRoutingKey()
     {
-        String exchangeName = "amq.direct";
-        String routingKey = "testRoutingKey";
+        final String exchangeName = "amq.direct";
+        final String routingKey = "testRoutingKey";
         final String replyTo = String.format("%s://%s//?routingkey='%s'", "direct", exchangeName, routingKey);
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setReplyTo(replyTo);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(exchangeName + "/" + routingKey, convertedMessage.getMessageHeader().getReplyTo(),
                 "Unexpected replyTo");
     }
 
     @Test
-    public void testReplyToConversionForFanoutExchange()
+    void replyToConversionForFanoutExchange()
     {
-        String exchangeName = "amq.fanout";
+        final String exchangeName = "amq.fanout";
         final String replyTo = String.format("%s://%s//", "fanout", exchangeName);
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setReplyTo(replyTo);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(exchangeName, convertedMessage.getMessageHeader().getReplyTo(), "Unexpected replyTo");
     }
 
     @Test
-    public void testReplyToConversionForDefaultDestination()
+    void replyToConversionForDefaultDestination()
     {
-        String exchangeName = "";
-        String routingKey = "testRoutingKey";
+        final String exchangeName = "";
+        final String routingKey = "testRoutingKey";
         final String replyTo = String.format("%s://%s//?routingkey='%s'", "direct", exchangeName, routingKey);
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setReplyTo(replyTo);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(routingKey, convertedMessage.getMessageHeader().getReplyTo(), "Unexpected replyTo");
     }
 
     @Test
-    public void testReplyToNonBurl()
+    void replyToNonBurl()
     {
         final String replyTo = "test/routing";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setReplyTo(replyTo);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(replyTo, convertedMessage.getMessageHeader().getReplyTo(), "Unexpected replyTo");
     }
 
     @Test
-    public void testTimestampConversion()
+    void timestampConversion()
     {
         final long creationTime = System.currentTimeMillis();
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setTimestamp(creationTime);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(creationTime, convertedMessage.getMessageHeader().getTimestamp(), "Unexpected timestamp");
     }
 
     @Test
-    public void testHeadersConversion()
+    void headersConversion()
     {
-        Map<String, Object> properties = new HashMap<>();
-        properties.put("testProperty1", "testProperty1Value");
-        properties.put("intProperty", 1);
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final Map<String, Object> properties = Map.of("testProperty1", "testProperty1Value",
+                "intProperty", 1);
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setHeaders(FieldTable.convertToFieldTable(properties));
         final AMQMessage originalMessage = createTestMessage(header);
 
@@ -252,46 +250,46 @@
     }
 
     @Test
-    public void testContentTypeConversion()
+    void contentTypeConversion()
     {
         final String contentType = "text/json";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setContentType(contentType);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(contentType, convertedMessage.getMessageHeader().getMimeType(), "Unexpected content type");
     }
 
     @Test
-    public void testTypeConversion()
+    void typeConversion()
     {
         final String type = "JMSType";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setType(type);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(type, convertedMessage.getMessageHeader().getType(), "Unexpected type");
     }
 
     @Test
-    public void testApplicationIdConversion()
+    void applicationIdConversion()
     {
         final String applicationId = "appId";
-        BasicContentHeaderProperties header = new BasicContentHeaderProperties();
+        final BasicContentHeaderProperties header = new BasicContentHeaderProperties();
         header.setAppId(applicationId);
         final AMQMessage originalMessage = createTestMessage(header);
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(applicationId, convertedMessage.getMessageHeader().getAppId(), "Unexpected applicationId");
     }
 
     @Test
-    public void testBasicPublishConversion()
+    void basicPublishConversion()
     {
         final String exchangeName = "amq.direct";
         final String testRoutingKey = "test-routing-key";
@@ -300,7 +298,7 @@
         originalMessage.getMessagePublishInfo().setRoutingKey(AMQShortString.valueOf(testRoutingKey));
         originalMessage.getMessagePublishInfo().setExchange(AMQShortString.valueOf(exchangeName));
 
-        InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
+        final InternalMessage convertedMessage = _messageConverter.convert(originalMessage, _addressSpace);
 
         assertEquals(exchangeName, convertedMessage.getTo(), "Unexpected to");
 
@@ -313,13 +311,14 @@
     }
 
     private AMQMessage createTestMessage(final BasicContentHeaderProperties basicContentHeaderProperties,
-                                         long arrivalTime)
+                                         final long arrivalTime)
     {
         return createTestMessage(basicContentHeaderProperties, null, arrivalTime);
     }
 
     private AMQMessage createTestMessage(final BasicContentHeaderProperties basicContentHeaderProperties,
-                                         final byte[] content, final long arrivalTime)
+                                         final byte[] content,
+                                         final long arrivalTime)
     {
         final ContentHeaderBody contentHeaderBody = mock(ContentHeaderBody.class);
         when(contentHeaderBody.getProperties()).thenReturn(basicContentHeaderProperties);
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ReferenceCountingTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ReferenceCountingTest.java
index f87d0f3..f45920a 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ReferenceCountingTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/ReferenceCountingTest.java
@@ -44,13 +44,13 @@
 /**
  * Tests that reference counting works correctly with AMQMessage and the message store
  */
-public class ReferenceCountingTest extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class ReferenceCountingTest extends UnitTestBase
 {
     private TestMemoryMessageStore _store;
 
-
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp() throws Exception
     {
         _store = new TestMemoryMessageStore();
     }
@@ -59,21 +59,21 @@
      * Check that when the reference count is decremented the message removes itself from the store
      */
     @Test
-    public void testMessageGetsRemoved()
+    void messageGetsRemoved()
     {
-        ContentHeaderBody chb = createPersistentContentHeader();
+        final ContentHeaderBody chb = createPersistentContentHeader();
 
-        MessagePublishInfo info = new MessagePublishInfo(null, false, false, null);
+        final MessagePublishInfo info = new MessagePublishInfo(null, false, false, null);
 
         final MessageMetaData mmd = new MessageMetaData(info, chb);
 
-        StoredMessage storedMessage = _store.addMessage(mmd).allContentAdded();
-        Transaction txn = _store.newTransaction();
+        final StoredMessage storedMessage = _store.addMessage(mmd).allContentAdded();
+        final Transaction txn = _store.newTransaction();
         txn.enqueueMessage(createTransactionLogResource("dummyQ"), createEnqueueableMessage(storedMessage));
         txn.commitTran();
-        AMQMessage message = new AMQMessage(storedMessage);
+        final AMQMessage message = new AMQMessage(storedMessage);
 
-        MessageReference ref = message.newReference();
+        final MessageReference ref = message.newReference();
 
         assertEquals(1, (long) getStoreMessageCount());
 
@@ -84,40 +84,37 @@
 
     private int getStoreMessageCount()
     {
-        MessageCounter counter = new MessageCounter();
+        final MessageCounter counter = new MessageCounter();
         _store.newMessageStoreReader().visitMessages(counter);
         return counter.getCount();
     }
 
     private ContentHeaderBody createPersistentContentHeader()
     {
-        BasicContentHeaderProperties bchp = new BasicContentHeaderProperties();
-        bchp.setDeliveryMode((byte)2);
-        ContentHeaderBody chb = new ContentHeaderBody(bchp);
-        return chb;
+        final BasicContentHeaderProperties bchp = new BasicContentHeaderProperties();
+        bchp.setDeliveryMode((byte) 2);
+        return new ContentHeaderBody(bchp);
     }
 
     @Test
-    public void testMessageRemains()
+    void testMessageRemains()
     {
-
-        MessagePublishInfo info = new MessagePublishInfo(null, false, false, null);
+        final MessagePublishInfo info = new MessagePublishInfo(null, false, false, null);
 
         final ContentHeaderBody chb = createPersistentContentHeader();
 
         final MessageMetaData mmd = new MessageMetaData(info, chb);
 
-        StoredMessage storedMessage = _store.addMessage(mmd).allContentAdded();
-        Transaction txn = _store.newTransaction();
+        final StoredMessage storedMessage = _store.addMessage(mmd).allContentAdded();
+        final Transaction txn = _store.newTransaction();
         txn.enqueueMessage(createTransactionLogResource("dummyQ"), createEnqueueableMessage(storedMessage));
         txn.commitTran();
-        AMQMessage message = new AMQMessage(storedMessage);
+        final AMQMessage message = new AMQMessage(storedMessage);
 
-
-        MessageReference ref = message.newReference();
+        final MessageReference ref = message.newReference();
 
         assertEquals(1, (long) getStoreMessageCount());
-        MessageReference ref2 = message.newReference();
+        final MessageReference ref2 = message.newReference();
         ref.release();
         assertEquals(1, (long) getStoreMessageCount());
     }
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/UnacknowledgedMessageMapTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/UnacknowledgedMessageMapTest.java
index fbe5f05..e7ab8cd 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/UnacknowledgedMessageMapTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/UnacknowledgedMessageMapTest.java
@@ -26,9 +26,8 @@
 import static org.mockito.Mockito.when;
 
 import java.util.Collection;
-
-import com.google.common.base.Function;
-import com.google.common.collect.Collections2;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 
 import org.junit.jupiter.api.Test;
 
@@ -37,24 +36,26 @@
 import org.apache.qpid.server.message.ServerMessage;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class UnacknowledgedMessageMapTest extends UnitTestBase
+@SuppressWarnings({"rawtypes", "unchecked"})
+class UnacknowledgedMessageMapTest extends UnitTestBase
 {
     public static final Function<MessageConsumerAssociation, MessageInstance>
-            MESSAGE_INSTANCE_FUNCTION = input -> input.getMessageInstance();
+            MESSAGE_INSTANCE_FUNCTION = MessageConsumerAssociation::getMessageInstance;
     private final MessageInstanceConsumer _consumer = mock(MessageInstanceConsumer.class);
 
     @Test
-    public void testDeletedMessagesCantBeAcknowledged()
+    void deletedMessagesCantBeAcknowledged()
     {
         UnacknowledgedMessageMap map = new UnacknowledgedMessageMapImpl(100, mock(CreditRestorer.class));
         final int expectedSize = 5;
         MessageInstance[] msgs = populateMap(map,expectedSize);
         assertEquals(expectedSize, (long) map.size());
         Collection<MessageConsumerAssociation> acknowledged = map.acknowledge(100, true);
-        Collection<MessageInstance> acknowledgedMessages = Collections2.transform(acknowledged, MESSAGE_INSTANCE_FUNCTION);
+        Collection<MessageInstance> acknowledgedMessages = acknowledged.stream().map(MESSAGE_INSTANCE_FUNCTION)
+                .collect(Collectors.toList());
         assertEquals(expectedSize, (long) acknowledged.size());
         assertEquals(0, (long) map.size());
-        for(int i = 0; i < expectedSize; i++)
+        for (int i = 0; i < expectedSize; i++)
         {
             assertTrue(acknowledgedMessages.contains(msgs[i]), "Message " + i + " is missing");
         }
@@ -68,32 +69,33 @@
         assertEquals(expectedSize, (long) map.size());
 
         acknowledged = map.acknowledge(100, true);
-        acknowledgedMessages = Collections2.transform(acknowledged, MESSAGE_INSTANCE_FUNCTION);
+        acknowledgedMessages = acknowledged.stream().map(MESSAGE_INSTANCE_FUNCTION)
+                .collect(Collectors.toList());
         assertEquals(expectedSize - 2, (long) acknowledged.size());
         assertEquals(0, (long) map.size());
-        for(int i = 0; i < expectedSize; i++)
+        for (int i = 0; i < expectedSize; i++)
         {
             assertEquals(i != 2 && i != 4, acknowledgedMessages.contains(msgs[i]));
         }
     }
 
-    public MessageInstance[] populateMap(final UnacknowledgedMessageMap map, int size)
+    MessageInstance[] populateMap(final UnacknowledgedMessageMap map, final int size)
     {
-        MessageInstance[] msgs = new MessageInstance[size];
-        for(int i = 0; i < size; i++)
+        final MessageInstance[] msgs = new MessageInstance[size];
+        for (int i = 0; i < size; i++)
         {
-            msgs[i] = createMessageInstance(i);
-            map.add((long)i, msgs[i], _consumer, true);
+            msgs[i] = createMessageInstance();
+            map.add(i, msgs[i], _consumer, true);
         }
         return msgs;
     }
 
-    private MessageInstance createMessageInstance(final int id)
+    private MessageInstance createMessageInstance()
     {
-        MessageInstance instance = mock(MessageInstance.class);
+        final MessageInstance instance = mock(MessageInstance.class);
         when(instance.makeAcquisitionUnstealable(_consumer)).thenReturn(Boolean.TRUE);
         when(instance.getAcquiringConsumer()).thenReturn(_consumer);
-        ServerMessage message = mock(ServerMessage.class);
+        final ServerMessage<?> message = mock(ServerMessage.class);
         when(message.getSize()).thenReturn(0L);
         when(instance.getMessage()).thenReturn(message);
         return instance;
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/BasicContentHeaderPropertiesTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/BasicContentHeaderPropertiesTest.java
index bc8dd38..47d0a59 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/BasicContentHeaderPropertiesTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/BasicContentHeaderPropertiesTest.java
@@ -23,7 +23,6 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import java.util.LinkedHashMap;
 import java.util.Map;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -35,8 +34,12 @@
 import org.apache.qpid.server.protocol.v0_8.FieldTableFactory;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class BasicContentHeaderPropertiesTest extends UnitTestBase
+class BasicContentHeaderPropertiesTest extends UnitTestBase
 {
+    private static final int BUFFER_SIZE = 1024 * 10;
+    private static final int POOL_SIZE = 20;
+    private static final double SPARSITY_FRACTION = 0.5;
+
     private final String _testString = "This is a test string";
     private BasicContentHeaderProperties _testProperties;
     private FieldTable _testTable;
@@ -50,11 +53,10 @@
     }
 
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp()
     {
-        Map<String, Object> headers = new LinkedHashMap<>();
-        headers.put("TestString", _testString);
-        headers.put("Testint", Integer.MAX_VALUE);
+        final Map<String, Object> headers = Map.of("TestString", _testString,
+                "Testint", Integer.MAX_VALUE);
         _testTable = FieldTableFactory.createFieldTable(headers);
 
         _testProperties = new BasicContentHeaderProperties();
@@ -62,7 +64,7 @@
     }
 
     @Test
-    public void testGetPropertyListSize()
+    void getPropertyListSize()
     {
         //needs a better test but at least we're exercising the code !
          // FT length is encoded in an int
@@ -76,84 +78,83 @@
         // 1 is for the Encoding Letter. here an 'S'
         expectedSize += 1 + EncodingUtils.encodedLongStringLength(_testString);
 
-
-        int size = _testProperties.getPropertyListSize();
+        final int size = _testProperties.getPropertyListSize();
 
         assertEquals(expectedSize, (long) size);
     }
 
     @Test
-    public void testGetSetPropertyFlags()
+    void getSetPropertyFlags()
     {
         _testProperties.setPropertyFlags(99);
         assertEquals(99, (long) _testProperties.getPropertyFlags());
     }
 
     @Test
-    public void testPopulatePropertiesFromBuffer() throws Exception
+    void populatePropertiesFromBuffer() throws Exception
     {
-        QpidByteBuffer buf = QpidByteBuffer.wrap(new byte[300]);
+        final QpidByteBuffer buf = QpidByteBuffer.wrap(new byte[300]);
         _testProperties.dispose();
         _testProperties = new BasicContentHeaderProperties(buf, 99, 99);
     }
 
     @Test
-    public void testSetGetContentType()
+    void setGetContentType()
     {
-        String contentType = "contentType";
+        final String contentType = "contentType";
         _testProperties.setContentType(contentType);
         assertEquals(contentType, _testProperties.getContentTypeAsString());
     }
 
     @Test
-    public void testSetGetEncoding()
+    void setGetEncoding()
     {
-        String encoding = "encoding";
+        final String encoding = "encoding";
         _testProperties.setEncoding(encoding);
         assertEquals(encoding, _testProperties.getEncodingAsString());
     }
 
     @Test
-    public void testSetGetHeaders()
+    void setGetHeaders()
     {
         _testProperties.setHeaders(_testTable);
         assertEquals(FieldTable.convertToMap(_testTable), _testProperties.getHeadersAsMap());
     }
 
     @Test
-    public void testSetGetDeliveryMode()
+    void setGetDeliveryMode()
     {
-        byte deliveryMode = 1;
+        final byte deliveryMode = 1;
         _testProperties.setDeliveryMode(deliveryMode);
         assertEquals(deliveryMode, (long) _testProperties.getDeliveryMode());
     }
 
     @Test
-    public void testSetGetPriority()
+    void setGetPriority()
     {
-        byte priority = 1;
+        final byte priority = 1;
         _testProperties.setPriority(priority);
         assertEquals(priority, (long) _testProperties.getPriority());
     }
 
     @Test
-    public void testSetGetCorrelationId()
+    void setGetCorrelationId()
     {
-        String correlationId = "correlationId";
+        final String correlationId = "correlationId";
         _testProperties.setCorrelationId(correlationId);
         assertEquals(correlationId, _testProperties.getCorrelationIdAsString());
     }
 
     @Test
-    public void testSetGetReplyTo()
+    void setGetReplyTo()
     {
-        String replyTo = "replyTo";
+        final String replyTo = "replyTo";
         _testProperties.setReplyTo(replyTo);
         assertEquals(replyTo, _testProperties.getReplyToAsString());
     }
 
     @Test
-    public void testSetGetExpiration()
+    void setGetExpiration()
     {
         long expiration = 999999999;
         _testProperties.setExpiration(expiration);
@@ -164,65 +165,61 @@
     }
 
     @Test
-    public void testSetGetMessageId()
+    void setGetMessageId()
     {
-        String messageId = "messageId";
+        final String messageId = "messageId";
         _testProperties.setMessageId(messageId);
         assertEquals(messageId, _testProperties.getMessageIdAsString());
     }
 
     @Test
-    public void testSetGetTimestamp()
+    void setGetTimestamp()
     {
-        long timestamp = System.currentTimeMillis();
+        final long timestamp = System.currentTimeMillis();
         _testProperties.setTimestamp(timestamp);
         assertEquals(timestamp, _testProperties.getTimestamp());
     }
 
     @Test
-    public void testSetGetType()
+    void setGetType()
     {
-        String type = "type";
+        final String type = "type";
         _testProperties.setType(type);
         assertEquals(type, _testProperties.getTypeAsString());
     }
 
     @Test
-    public void testSetGetUserId()
+    void setGetUserId()
     {
-        String userId = "userId";
+        final String userId = "userId";
         _testProperties.setUserId(userId);
         assertEquals(userId, _testProperties.getUserIdAsString());
     }
 
     @Test
-    public void testSetGetAppId()
+    void setGetAppId()
     {
-        String appId = "appId";
+        final String appId = "appId";
         _testProperties.setAppId(appId);
         assertEquals(appId, _testProperties.getAppIdAsString());
     }
 
     @Test
-    public void testSetGetClusterId()
+    void setGetClusterId()
     {
-        String clusterId = "clusterId";
+        final String clusterId = "clusterId";
         _testProperties.setClusterId(clusterId);
         assertEquals(clusterId, _testProperties.getClusterIdAsString());
     }
 
-    private static final int BUFFER_SIZE = 1024 * 10;
-    private static final int POOL_SIZE = 20;
-    private static final double SPARSITY_FRACTION = 0.5;
-
     @Test
-    public void testReallocate() throws Exception
+    void reallocate() throws Exception
     {
         try
         {
             QpidByteBuffer.deinitialisePool();
             QpidByteBuffer.initialisePool(BUFFER_SIZE, POOL_SIZE, SPARSITY_FRACTION);
-            try (QpidByteBuffer buffer = QpidByteBuffer.allocateDirect(BUFFER_SIZE))
+            try (final QpidByteBuffer buffer = QpidByteBuffer.allocateDirect(BUFFER_SIZE))
             {
                 // set some test fields
                 _testProperties.setContentType("text/plain");
@@ -235,12 +232,12 @@
                 final int pos = BUFFER_SIZE - propertyListSize * 2;
                 buffer.position(pos);
 
-                try (QpidByteBuffer propertiesBuffer = buffer.view(0, propertyListSize))
+                try (final QpidByteBuffer propertiesBuffer = buffer.view(0, propertyListSize))
                 {
                     _testProperties.writePropertyListPayload(propertiesBuffer);
                     propertiesBuffer.flip();
 
-                    BasicContentHeaderProperties testProperties = new BasicContentHeaderProperties(propertiesBuffer, flags, propertyListSize);
+                    final BasicContentHeaderProperties testProperties = new BasicContentHeaderProperties(propertiesBuffer, flags, propertyListSize);
                     final Map<String, Object> headersBeforeReallocation = testProperties.getHeadersAsMap();
                     assertEquals(headers, headersBeforeReallocation, "Unexpected headers");
 
diff --git a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/MessagePublishInfoImplTest.java b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/MessagePublishInfoImplTest.java
index c85ec90..5d7f571 100644
--- a/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/MessagePublishInfoImplTest.java
+++ b/broker-plugins/amqp-0-8-protocol/src/test/java/org/apache/qpid/server/protocol/v0_8/transport/MessagePublishInfoImplTest.java
@@ -30,24 +30,25 @@
 import org.apache.qpid.server.protocol.v0_8.AMQShortString;
 import org.apache.qpid.test.utils.UnitTestBase;
 
-public class MessagePublishInfoImplTest extends UnitTestBase
+class MessagePublishInfoImplTest extends UnitTestBase
 {
-    private MessagePublishInfo _mpi;
     private final AMQShortString _exchange = AMQShortString.createAMQShortString("exchange");
     private final AMQShortString _routingKey = AMQShortString.createAMQShortString("routingKey");
 
+    private MessagePublishInfo _mpi;
+
     @BeforeEach
-    public void setUp() throws Exception
+    void setUp()
     {
         _mpi = new MessagePublishInfo(_exchange, true, true, _routingKey);
     }
 
     /** Test that we can update the exchange value. */
     @Test
-    public void testExchange()
+    void exchange()
     {
         assertEquals(_exchange, _mpi.getExchange());
-        AMQShortString newExchange = AMQShortString.createAMQShortString("newExchange");
+        final AMQShortString newExchange = AMQShortString.createAMQShortString("newExchange");
         //Check we can update the exchange
         _mpi.setExchange(newExchange);
         assertEquals(newExchange, _mpi.getExchange());
@@ -59,12 +60,12 @@
      * Check that the immedate value is set correctly and defaulted correctly
      */
     @Test
-    public void testIsImmediate()
+    void isImmediate()
     {
         //Check that the set value is correct
         assertTrue(_mpi.isImmediate(), "Set value for immediate not as expected");
 
-        MessagePublishInfo mpi = new MessagePublishInfo();
+        final MessagePublishInfo mpi = new MessagePublishInfo();
 
         assertFalse(mpi.isImmediate(), "Default value for immediate should be false");
 
@@ -77,11 +78,11 @@
      * Check that the mandatory value is set correctly and defaulted correctly
      */
     @Test
-    public void testIsMandatory()
+    void isMandatory()
     {
         assertTrue(_mpi.isMandatory(), "Set value for mandatory not as expected");
 
-        MessagePublishInfo mpi = new MessagePublishInfo();
+        final MessagePublishInfo mpi = new MessagePublishInfo();
 
         assertFalse(mpi.isMandatory(), "Default value for mandatory should be false");
 
@@ -94,10 +95,10 @@
      * Check that the routingKey value is perserved
      */
     @Test
-    public void testRoutingKey()
+    void routingKey()
     {
         assertEquals(_routingKey, _mpi.getRoutingKey());
-        AMQShortString newRoutingKey = AMQShortString.createAMQShortString("newRoutingKey");
+        final AMQShortString newRoutingKey = AMQShortString.createAMQShortString("newRoutingKey");
 
         //Check we can update the routingKey
         _mpi.setRoutingKey(newRoutingKey);