diff --git a/fit/src/main/java/org/apache/olingo/fit/Services.java b/fit/src/main/java/org/apache/olingo/fit/Services.java
index 698938e..1911bf1 100644
--- a/fit/src/main/java/org/apache/olingo/fit/Services.java
+++ b/fit/src/main/java/org/apache/olingo/fit/Services.java
@@ -783,9 +783,6 @@
         } else {
           jsonSerializer.write(writer, container);
         }
-        writer.flush();
-        writer.close();
-
         return xml.createResponse(
             location,
             new ByteArrayInputStream(content.toByteArray()),
diff --git a/fit/src/main/java/org/apache/olingo/fit/utils/FSManager.java b/fit/src/main/java/org/apache/olingo/fit/utils/FSManager.java
index 8202619..d79ebf0 100644
--- a/fit/src/main/java/org/apache/olingo/fit/utils/FSManager.java
+++ b/fit/src/main/java/org/apache/olingo/fit/utils/FSManager.java
@@ -122,8 +122,7 @@
     content.reset();
 
     new JsonSerializer(true, ContentType.JSON_FULL_METADATA).write(writer, container);
-    writer.flush();
-
+    
     putInMemory(new ByteArrayInputStream(content.toByteArray()), getAbsolutePath(relativePath, Accept.JSON_FULLMETA));
   }
 
diff --git a/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientLink.java b/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientLink.java
index 35f89fb..c3cd43c 100644
--- a/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientLink.java
+++ b/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientLink.java
@@ -107,7 +107,7 @@
    */
   private String mediaETag;
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
 
   /**
    * Constructor.
diff --git a/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientServiceDocument.java b/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientServiceDocument.java
index d78b7bf..65e311d 100644
--- a/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientServiceDocument.java
+++ b/lib/client-api/src/main/java/org/apache/olingo/client/api/domain/ClientServiceDocument.java
@@ -25,13 +25,13 @@
 
 public class ClientServiceDocument {
 
-  private final Map<String, URI> entitySets = new HashMap<String, URI>();
+  private final Map<String, URI> entitySets = new HashMap<>();
 
-  private final Map<String, URI> functionImports = new HashMap<String, URI>();
+  private final Map<String, URI> functionImports = new HashMap<>();
 
-  private final Map<String, URI> singletons = new HashMap<String, URI>();
+  private final Map<String, URI> singletons = new HashMap<>();
 
-  private final Map<String, URI> relatedServiceDocuments = new HashMap<String, URI>();
+  private final Map<String, URI> relatedServiceDocuments = new HashMap<>();
 
   public Map<String, URI> getEntitySets() {
     return entitySets;
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/ConfigurationImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/ConfigurationImpl.java
index 2a49935..86c435d 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/ConfigurationImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/ConfigurationImpl.java
@@ -62,7 +62,7 @@
 
   public static final int DEFAULT_BUFFER_SIZE = 4 * 1024 * 1024;  // 4MB
 
-  private final Map<String, Object> CONF = new HashMap<String, Object>();
+  private final Map<String, Object> CONF = new HashMap<>();
 
   private transient ExecutorService executor = createExecutor(10);
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataErrorResponseChecker.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataErrorResponseChecker.java
index 7d2a38b..1f8413b 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataErrorResponseChecker.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataErrorResponseChecker.java
@@ -72,12 +72,7 @@
               }
             }
           }
-        } catch (final RuntimeException e) {
-          LOG.warn("Error deserializing error response", e);
-          error = getGenericError(
-              statusLine.getStatusCode(),
-              statusLine.getReasonPhrase());
-        } catch (final ODataDeserializerException e) {
+        } catch (final RuntimeException | ODataDeserializerException e) {
           LOG.warn("Error deserializing error response", e);
           error = getGenericError(
               statusLine.getStatusCode(),
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataHeadersImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataHeadersImpl.java
index 9f79fbb..4341585 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataHeadersImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/header/ODataHeadersImpl.java
@@ -29,7 +29,7 @@
   /**
    * OData request/response header key/value pairs.
    */
-  private final Map<String, String> headers = new TreeMap<String, String>(String.CASE_INSENSITIVE_ORDER);
+  private final Map<String, String> headers = new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
   @Override
   public ODataHeaders setHeader(final String name, final String value) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestFactoryImpl.java
index 14e1e2a..1a3021a 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestFactoryImpl.java
@@ -36,7 +36,7 @@
 
   @Override
   public <R extends ODataResponse> AsyncRequestWrapper<R> getAsyncRequestWrapper(final ODataRequest odataRequest) {
-    return new AsyncRequestWrapperImpl<R>(client, odataRequest);
+    return new AsyncRequestWrapperImpl<>(client, odataRequest);
   }
 
   @Override
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestWrapperImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestWrapperImpl.java
index 736d2c7..b691c52 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestWrapperImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/AsyncRequestWrapperImpl.java
@@ -95,12 +95,10 @@
 
     this.request = odataClient.getConfiguration().getHttpUriRequestFactory().create(method, this.uri);
 
-    if (request instanceof HttpEntityEnclosingRequestBase) {
-      if (odataRequest instanceof AbstractODataBasicRequest) {
-        AbstractODataBasicRequest<?> br = (AbstractODataBasicRequest<?>) odataRequest;
-        HttpEntityEnclosingRequestBase httpRequest = ((HttpEntityEnclosingRequestBase) request);
-        httpRequest.setEntity(new InputStreamEntity(br.getPayload(), -1));
-      }
+    if (request instanceof HttpEntityEnclosingRequestBase && odataRequest instanceof AbstractODataBasicRequest) {
+      AbstractODataBasicRequest<?> br = (AbstractODataBasicRequest<?>) odataRequest;
+      HttpEntityEnclosingRequestBase httpRequest = ((HttpEntityEnclosingRequestBase) request);
+      httpRequest.setEntity(new InputStreamEntity(br.getPayload(), -1));
     }
   }
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchRequest.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchRequest.java
index 8655ccc..122440f 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchRequest.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchRequest.java
@@ -48,7 +48,7 @@
   /**
    * Expected batch response items.
    */
-  protected final List<ODataBatchResponseItem> expectedResItems = new ArrayList<ODataBatchResponseItem>();
+  protected final List<ODataBatchResponseItem> expectedResItems = new ArrayList<>();
 
   /**
    * Constructor.
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchResponseItem.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchResponseItem.java
index 0f82d42..5b5eeed 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchResponseItem.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/AbstractODataBatchResponseItem.java
@@ -41,7 +41,7 @@
   /**
    * Expected OData responses for the current batch response item.
    */
-  protected final Map<String, ODataResponse> responses = new HashMap<String, ODataResponse>();
+  protected final Map<String, ODataResponse> responses = new HashMap<>();
 
   /**
    * Expected OData responses iterator.
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/ODataBatchUtilities.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/ODataBatchUtilities.java
index ad36781..313378f 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/ODataBatchUtilities.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/batch/ODataBatchUtilities.java
@@ -166,7 +166,7 @@
    */
   public static Map<String, Collection<String>> readHeaders(final ODataBatchLineIterator iterator) {
     final Map<String, Collection<String>> target =
-            new TreeMap<String, Collection<String>>(String.CASE_INSENSITIVE_ORDER);
+            new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
     readHeaders(iterator, target);
     return target;
@@ -214,7 +214,7 @@
       if (targetMap.containsKey(key)) {
         value = targetMap.get(key);
       } else {
-        value = new HashSet<String>();
+        value = new HashSet<>();
         targetMap.put(key, value);
       }
       value.add(headerLine.substring(sep + 1, headerLine.length()).trim());
@@ -262,7 +262,7 @@
       final Matcher matcher = RESPONSE_PATTERN.matcher(line.trim());
 
       if (matcher.matches()) {
-        return new AbstractMap.SimpleEntry<Integer, String>(Integer.valueOf(matcher.group(1)), matcher.group(2));
+        return new AbstractMap.SimpleEntry<>(Integer.valueOf(matcher.group(1)), matcher.group(2));
       }
     }
 
@@ -280,7 +280,7 @@
           final ODataBatchLineIterator iterator, final String boundary) {
 
     final Map<String, Collection<String>> headers =
-            new TreeMap<String, Collection<String>>(String.CASE_INSENSITIVE_ORDER);
+            new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
     final String line = ODataBatchUtilities.readBatchPart(new ODataBatchController(iterator, boundary), true);
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/cud/CUDRequestFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/cud/CUDRequestFactoryImpl.java
index 5be3f41..57dd04e 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/cud/CUDRequestFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/cud/CUDRequestFactoryImpl.java
@@ -56,7 +56,7 @@
   public <E extends ClientEntity> ODataEntityCreateRequest<E> getEntityCreateRequest(
       final URI targetURI, final E entity) {
 
-    return new ODataEntityCreateRequestImpl<E>(client, targetURI, entity);
+    return new ODataEntityCreateRequestImpl<>(client, targetURI, entity);
   }
 
   @Override
@@ -66,10 +66,10 @@
     final ODataEntityUpdateRequest<E> req;
 
     if (client.getConfiguration().isUseXHTTPMethod()) {
-      req = new ODataEntityUpdateRequestImpl<E>(client, HttpMethod.POST, targetURI, changes);
+      req = new ODataEntityUpdateRequestImpl<>(client, HttpMethod.POST, targetURI, changes);
       req.setXHTTPMethod(type.getMethod().name());
     } else {
-      req = new ODataEntityUpdateRequestImpl<E>(client, type.getMethod(), targetURI, changes);
+      req = new ODataEntityUpdateRequestImpl<>(client, type.getMethod(), targetURI, changes);
     }
 
     return req;
@@ -86,10 +86,10 @@
     final ODataEntityUpdateRequest<E> req;
 
     if (client.getConfiguration().isUseXHTTPMethod()) {
-      req = new ODataEntityUpdateRequestImpl<E>(client, HttpMethod.POST, entity.getEditLink(), entity);
+      req = new ODataEntityUpdateRequestImpl<>(client, HttpMethod.POST, entity.getEditLink(), entity);
       req.setXHTTPMethod(type.getMethod().name());
     } else {
-      req = new ODataEntityUpdateRequestImpl<E>(client, type.getMethod(), entity.getEditLink(), entity);
+      req = new ODataEntityUpdateRequestImpl<>(client, type.getMethod(), entity.getEditLink(), entity);
     }
 
     return req;
@@ -189,7 +189,7 @@
   public <E extends ClientEntity> ODataMediaEntityCreateRequest<E> getMediaEntityCreateRequest(
       final URI targetURI, final InputStream media) {
 
-    return new ODataMediaEntityCreateRequestImpl<E>(client, targetURI, media);
+    return new ODataMediaEntityCreateRequestImpl<>(client, targetURI, media);
   }
 
   @Override
@@ -213,10 +213,10 @@
     final ODataMediaEntityUpdateRequest<E> req;
 
     if (client.getConfiguration().isUseXHTTPMethod()) {
-      req = new ODataMediaEntityUpdateRequestImpl<E>(client, HttpMethod.POST, URIUtils.addValueSegment(editURI), media);
+      req = new ODataMediaEntityUpdateRequestImpl<>(client, HttpMethod.POST, URIUtils.addValueSegment(editURI), media);
       req.setXHTTPMethod(HttpMethod.PUT.name());
     } else {
-      req = new ODataMediaEntityUpdateRequestImpl<E>(client, HttpMethod.PUT, URIUtils.addValueSegment(editURI), media);
+      req = new ODataMediaEntityUpdateRequestImpl<>(client, HttpMethod.PUT, URIUtils.addValueSegment(editURI), media);
     }
 
     return req;
@@ -241,7 +241,7 @@
       final URI reference) {
     final URI contextURI = client.newURIBuilder(serviceRoot.toASCIIString()).appendMetadataSegment()
                                                                             .appendRefSegment().build();
-    ResWrap<URI> wrappedPayload = new ResWrap<URI>(contextURI, null, reference);
+    ResWrap<URI> wrappedPayload = new ResWrap<>(contextURI, null, reference);
 
     return new ODataReferenceAddingRequestImpl(client, HttpMethod.POST, targetURI, wrappedPayload);
   }
@@ -251,7 +251,7 @@
       final URI reference) {
     // See OData Protocol 11.4.6.3
     final URI contextURI = client.newURIBuilder(serviceRoot.toASCIIString()).appendMetadataSegment().build();
-    ResWrap<URI> wrappedPayload = new ResWrap<URI>(contextURI, null, reference);
+    ResWrap<URI> wrappedPayload = new ResWrap<>(contextURI, null, reference);
 
     return new ODataReferenceAddingRequestImpl(client, HttpMethod.PUT, targetURI, wrappedPayload);
   }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/AbstractODataInvokeRequest.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/AbstractODataInvokeRequest.java
index 502c521..8bb5a6d 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/AbstractODataInvokeRequest.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/AbstractODataInvokeRequest.java
@@ -79,7 +79,7 @@
     super(odataClient, method, uri);
 
     this.reference = reference;
-    this.parameters = new LinkedHashMap<String, ClientValue>();
+    this.parameters = new LinkedHashMap<>();
   }
 
   @Override
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/EdmEnabledInvokeRequestFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/EdmEnabledInvokeRequestFactoryImpl.java
index bb488d5..fa64a52 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/EdmEnabledInvokeRequestFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/EdmEnabledInvokeRequestFactoryImpl.java
@@ -41,7 +41,7 @@
           final HttpMethod method, final URI uri, final Class<RES> resultRef,
           final Map<String, ClientValue> parameters) {
 
-    final ODataInvokeRequest<RES> request = new ODataInvokeRequestImpl<RES>(edmClient, resultRef, method, uri);
+    final ODataInvokeRequest<RES> request = new ODataInvokeRequestImpl<>(edmClient, resultRef, method, uri);
     if (parameters != null) {
       request.setParameters(parameters);
     }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/InvokeRequestFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/InvokeRequestFactoryImpl.java
index b01c54a..e98ae26 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/InvokeRequestFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/invoke/InvokeRequestFactoryImpl.java
@@ -40,7 +40,7 @@
           final HttpMethod method, final URI uri, final Class<RES> resultRef,
           final Map<String, ClientValue> parameters) {
 
-    final ODataInvokeRequest<RES> request = new ODataInvokeRequestImpl<RES>(client, resultRef, method, uri);
+    final ODataInvokeRequest<RES> request = new ODataInvokeRequestImpl<>(client, resultRef, method, uri);
     if (parameters != null) {
       request.setParameters(parameters);
     }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/ODataEntitySetIteratorRequestImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/ODataEntitySetIteratorRequestImpl.java
index db390a0..b0f97f1 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/ODataEntitySetIteratorRequestImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/ODataEntitySetIteratorRequestImpl.java
@@ -74,7 +74,7 @@
     @Override
     public ClientEntitySetIterator<ES, E> getBody() {
       if (entitySetIterator == null) {
-        entitySetIterator = new ClientEntitySetIterator<ES, E>(
+        entitySetIterator = new ClientEntitySetIterator<>(
                 odataClient, getRawResponse(), ContentType.parse(getContentType()));
       }
       return entitySetIterator;
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/RetrieveRequestFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/RetrieveRequestFactoryImpl.java
index 6b0f012..6cbba1c 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/RetrieveRequestFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/retrieve/RetrieveRequestFactoryImpl.java
@@ -93,27 +93,27 @@
 
   @Override
   public ODataEntitySetRequest<ClientEntitySet> getEntitySetRequest(final URI uri) {
-    return new ODataEntitySetRequestImpl<ClientEntitySet>(client, uri);
+    return new ODataEntitySetRequestImpl<>(client, uri);
   }
 
   @Override
   public ODataEntitySetIteratorRequest<ClientEntitySet, ClientEntity> getEntitySetIteratorRequest(final URI uri) {
-    return new ODataEntitySetIteratorRequestImpl<ClientEntitySet, ClientEntity>(client, uri);
+    return new ODataEntitySetIteratorRequestImpl<>(client, uri);
   }
 
   @Override
   public ODataEntityRequest<ClientSingleton> getSingletonRequest(final URI uri) {
-    return new ODataEntityRequestImpl<ClientSingleton>(client, uri);
+    return new ODataEntityRequestImpl<>(client, uri);
   }
 
   @Override
   public ODataEntityRequest<ClientEntity> getEntityRequest(final URI uri) {
-    return new ODataEntityRequestImpl<ClientEntity>(client, uri);
+    return new ODataEntityRequestImpl<>(client, uri);
   }
 
   @Override
   public ODataPropertyRequest<ClientProperty> getPropertyRequest(final URI uri) {
-    return new ODataPropertyRequestImpl<ClientProperty>(client, uri);
+    return new ODataPropertyRequestImpl<>(client, uri);
   }
 
   @Override
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/streamed/AbstractODataStreamedRequest.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/streamed/AbstractODataStreamedRequest.java
index afb6b40..e3f5624 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/streamed/AbstractODataStreamedRequest.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/request/streamed/AbstractODataStreamedRequest.java
@@ -62,7 +62,7 @@
    * Wrapper for actual streamed request's future. This holds information about the HTTP request / response currently
    * open.
    */
-  protected final Wrapper<Future<HttpResponse>> futureWrapper = new Wrapper<Future<HttpResponse>>();
+  protected final Wrapper<Future<HttpResponse>> futureWrapper = new Wrapper<>();
 
   /**
    * Constructor.
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/response/AbstractODataResponse.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/response/AbstractODataResponse.java
index d16006c..0cf342a 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/response/AbstractODataResponse.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/communication/response/AbstractODataResponse.java
@@ -77,7 +77,7 @@
    * Response headers.
    */
   protected final Map<String, Collection<String>> headers =
-      new TreeMap<String, Collection<String>>(String.CASE_INSENSITIVE_ORDER);
+      new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
 
   /**
    * Response code.
@@ -154,11 +154,7 @@
     try {
       this.payload = res.getEntity() == null ? null : res.getEntity().getContent();
       this.inputContent = null;
-    } catch (final IllegalStateException e) {
-      HttpClientUtils.closeQuietly(res);
-      LOG.error("Error retrieving payload", e);
-      throw new ODataRuntimeException(e);
-    } catch (final IOException e) {
+    } catch (final IllegalStateException | IOException e) {
       HttpClientUtils.closeQuietly(res);
       LOG.error("Error retrieving payload", e);
       throw new ODataRuntimeException(e);
@@ -168,7 +164,7 @@
       if (headers.containsKey(header.getName())) {
         headerValues = headers.get(header.getName());
       } else {
-        headerValues = new HashSet<String>();
+        headerValues = new HashSet<>();
         headers.put(header.getName(), headerValues);
       }
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/JSONServiceDocumentDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/JSONServiceDocumentDeserializer.java
index 5883aa5..dcccc75 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/JSONServiceDocumentDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/JSONServiceDocumentDeserializer.java
@@ -92,7 +92,7 @@
       }
     }
 
-    return new ResWrap<ServiceDocument>(contextURL, metadataETag, serviceDocument);
+    return new ResWrap<>(contextURL, metadataETag, serviceDocument);
   }
 
   public ResWrap<ServiceDocument> toServiceDocument(final InputStream input) throws ODataDeserializerException {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/ServiceDocumentImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/ServiceDocumentImpl.java
index a0a1630..bc9db82 100755
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/ServiceDocumentImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/ServiceDocumentImpl.java
@@ -30,10 +30,10 @@
 
   private String title;
 
-  private final List<ServiceDocumentItem> entitySets = new ArrayList<ServiceDocumentItem>();
-  private final List<ServiceDocumentItem> functionImports = new ArrayList<ServiceDocumentItem>();
-  private final List<ServiceDocumentItem> singletons = new ArrayList<ServiceDocumentItem>();
-  private final List<ServiceDocumentItem> relatedServiceDocuments = new ArrayList<ServiceDocumentItem>();
+  private final List<ServiceDocumentItem> entitySets = new ArrayList<>();
+  private final List<ServiceDocumentItem> functionImports = new ArrayList<>();
+  private final List<ServiceDocumentItem> singletons = new ArrayList<>();
+  private final List<ServiceDocumentItem> relatedServiceDocuments = new ArrayList<>();
 
   private String metadata;
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/XMLServiceDocumentDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/XMLServiceDocumentDeserializer.java
index 5bb3fe9..3ea155a 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/data/XMLServiceDocumentDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/data/XMLServiceDocumentDeserializer.java
@@ -120,7 +120,7 @@
         ? URIUtils.getURI(base, "$metadata")
         : URIUtils.getURI(base, contextURL.toASCIIString())).toASCIIString());
 
-    return new ResWrap<ServiceDocument>(
+    return new ResWrap<>(
         contextURL == null ? null : URIUtils.getURI(sdoc.getBaseURI(), contextURL),
         metadataETag, sdoc);
   }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientCollectionValueImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientCollectionValueImpl.java
index 0a0ac33..64b8e66 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientCollectionValueImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientCollectionValueImpl.java
@@ -57,7 +57,7 @@
 
   @Override
   public Collection<Object> asJavaCollection() {
-    final List<Object> result = new ArrayList<Object>();
+    final List<Object> result = new ArrayList<>();
     for (ClientValue value : values) {
       if (value.isPrimitive()) {
         result.add(value.asPrimitive().toValue());
@@ -76,7 +76,7 @@
   /**
    * Values.
    */
-  protected final List<OV> values = new ArrayList<OV>();
+  protected final List<OV> values = new ArrayList<>();
 
   /**
    * Adds a value to the collection.
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientComplexValueImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientComplexValueImpl.java
index fd8d36f..f229df5 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientComplexValueImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientComplexValueImpl.java
@@ -36,19 +36,19 @@
   /**
    * Navigation links (might contain in-line entities or entity sets).
    */
-  private final List<ClientLink> navigationLinks = new ArrayList<ClientLink>();
+  private final List<ClientLink> navigationLinks = new ArrayList<>();
 
   /**
    * Association links.
    */
-  private final List<ClientLink> associationLinks = new ArrayList<ClientLink>();
+  private final List<ClientLink> associationLinks = new ArrayList<>();
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
 
   /**
    * Complex type fields.
    */
-  private final Map<String, ClientProperty> fields = new LinkedHashMap<String, ClientProperty>();
+  private final Map<String, ClientProperty> fields = new LinkedHashMap<>();
 
   /**
    * Constructor.
@@ -137,7 +137,7 @@
 
   @Override
   public Map<String, Object> asJavaMap() {
-    final Map<String, Object> result = new LinkedHashMap<String, Object>();
+    final Map<String, Object> result = new LinkedHashMap<>();
     for (Map.Entry<String, ClientProperty> entry : fields.entrySet()) {
       Object value = null;
       if (entry.getValue().hasPrimitiveValue()) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaImpl.java
index f0ce647..ebd928c 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaImpl.java
@@ -28,11 +28,11 @@
 
 public class ClientDeltaImpl extends ClientEntitySetImpl implements ClientDelta {
 
-  private final List<ClientDeletedEntity> deletedEntities = new ArrayList<ClientDeletedEntity>();
+  private final List<ClientDeletedEntity> deletedEntities = new ArrayList<>();
 
-  private final List<ClientDeltaLink> addedLinks = new ArrayList<ClientDeltaLink>();
+  private final List<ClientDeltaLink> addedLinks = new ArrayList<>();
 
-  private final List<ClientDeltaLink> deletedLinks = new ArrayList<ClientDeltaLink>();
+  private final List<ClientDeltaLink> deletedLinks = new ArrayList<>();
 
   public ClientDeltaImpl() {
     super();
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaLinkImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaLinkImpl.java
index 0d8fd52..3975a02 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaLinkImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientDeltaLinkImpl.java
@@ -34,7 +34,7 @@
 
   private URI target;
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
 
   public ClientDeltaLinkImpl() {
     super(null);
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntityImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntityImpl.java
index 76ee05f..74e59b5 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntityImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntityImpl.java
@@ -63,27 +63,27 @@
    */
   private URI editLink;
 
-  private final List<ClientProperty> properties = new ArrayList<ClientProperty>();
+  private final List<ClientProperty> properties = new ArrayList<>();
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
 
   private final FullQualifiedName typeName;
   /**
    * Navigation links (might contain in-line entities or entity sets).
    */
-  private final List<ClientLink> navigationLinks = new ArrayList<ClientLink>();
+  private final List<ClientLink> navigationLinks = new ArrayList<>();
   /**
    * Association links.
    */
-  private final List<ClientLink> associationLinks = new ArrayList<ClientLink>();
+  private final List<ClientLink> associationLinks = new ArrayList<>();
   /**
    * Media edit links.
    */
-  private final List<ClientLink> mediaEditLinks = new ArrayList<ClientLink>();
+  private final List<ClientLink> mediaEditLinks = new ArrayList<>();
   /**
    * Operations (legacy, functions, actions).
    */
-  private final List<ClientOperation> operations = new ArrayList<ClientOperation>();
+  private final List<ClientOperation> operations = new ArrayList<>();
 
   public ClientEntityImpl(final FullQualifiedName typeName) {
     super(typeName == null ? null : typeName.toString());
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntitySetImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntitySetImpl.java
index a979196..f58dee9 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntitySetImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientEntitySetImpl.java
@@ -44,11 +44,11 @@
 
   private URI deltaLink;
 
-  private final List<ClientEntity> entities = new ArrayList<ClientEntity>();
+  private final List<ClientEntity> entities = new ArrayList<>();
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
   
-  private final List<ClientOperation> operations = new ArrayList<ClientOperation>();
+  private final List<ClientOperation> operations = new ArrayList<>();
 
   public ClientEntitySetImpl() {
     super(null);
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientObjectFactoryImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientObjectFactoryImpl.java
index 5914cee..7abe3a4 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientObjectFactoryImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientObjectFactoryImpl.java
@@ -127,7 +127,7 @@
 
   @Override
   public ClientCollectionValue<ClientValue> newCollectionValue(final String typeName) {
-    return new ClientCollectionValueImpl<ClientValue>(typeName);
+    return new ClientCollectionValueImpl<>(typeName);
   }
 
   @Override
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientPropertyImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientPropertyImpl.java
index a8447a9..131ee0a 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientPropertyImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/domain/ClientPropertyImpl.java
@@ -28,9 +28,9 @@
 
 public final class ClientPropertyImpl extends ClientValuableImpl implements ClientProperty {
 
-  private final List<ClientAnnotation> annotations = new ArrayList<ClientAnnotation>();
+  private final List<ClientAnnotation> annotations = new ArrayList<>();
   private final String name;
-  private final List<ClientOperation> operations = new ArrayList<ClientOperation>();
+  private final List<ClientOperation> operations = new ArrayList<>();
   
   public ClientPropertyImpl(final String name, final ClientValue value) {
     super(value);
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlEdmProvider.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlEdmProvider.java
index f683a68..02e88ef 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlEdmProvider.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlEdmProvider.java
@@ -174,7 +174,7 @@
 
   @Override
   public List<CsdlAliasInfo> getAliasInfos() throws ODataException {
-    ArrayList<CsdlAliasInfo> aliasInfo = new ArrayList<CsdlAliasInfo>();
+    ArrayList<CsdlAliasInfo> aliasInfo = new ArrayList<>();
     for (CsdlSchema schema : xmlSchemas.values()) {
       if (schema.getAlias() != null) {
         aliasInfo.add(new CsdlAliasInfo().setNamespace(schema.getNamespace()).setAlias(schema.getAlias()));
@@ -185,7 +185,7 @@
 
   @Override
   public List<CsdlSchema> getSchemas() throws ODataException {
-    return new ArrayList<CsdlSchema>(xmlSchemas.values());
+    return new ArrayList<>(xmlSchemas.values());
   }
 
   @Override
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlXMLMetadata.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlXMLMetadata.java
index 4c5c6a4..98b4fcf 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlXMLMetadata.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/ClientCsdlXMLMetadata.java
@@ -73,7 +73,7 @@
 
   @Override
   public Map<String, CsdlSchema> getSchemaByNsOrAlias() {
-    final Map<String, CsdlSchema> schemaByNsOrAlias = new HashMap<String, CsdlSchema>();
+    final Map<String, CsdlSchema> schemaByNsOrAlias = new HashMap<>();
     for (CsdlSchema schema : getSchemas()) {
       schemaByNsOrAlias.put(schema.getNamespace(), schema);
       if (StringUtils.isNotBlank(schema.getAlias())) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlDataServices.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlDataServices.java
index 86606fb..2a3301e 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlDataServices.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlDataServices.java
@@ -38,7 +38,7 @@
 
   private static final long serialVersionUID = 4200317286476885204L;
 
-  private final List<CsdlSchema> schemas = new ArrayList<CsdlSchema>();
+  private final List<CsdlSchema> schemas = new ArrayList<>();
   
   private String dataServiceVersion;
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEdmx.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEdmx.java
index 5147a5c..3e25690 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEdmx.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEdmx.java
@@ -39,7 +39,7 @@
 
   private static final long serialVersionUID = -6293476719276092572L;
 
-  private final List<Reference> references = new ArrayList<Reference>();
+  private final List<Reference> references = new ArrayList<>();
 
   private String version;
 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEntityKey.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEntityKey.java
index 574a6b9..93c98aa 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEntityKey.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlEntityKey.java
@@ -37,7 +37,7 @@
 
   private static final long serialVersionUID = 520227585458843347L;
 
-  private final List<CsdlPropertyRef> propertyRefs = new ArrayList<CsdlPropertyRef>();
+  private final List<CsdlPropertyRef> propertyRefs = new ArrayList<>();
 
   public List<CsdlPropertyRef> getPropertyRefs() {
     return propertyRefs;
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlReference.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlReference.java
index 1e6c5f5..45dadfc 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlReference.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/edm/xml/ClientCsdlReference.java
@@ -42,9 +42,9 @@
   private static final long serialVersionUID = 7720274712545267654L;
 
   private URI uri;
-  private final List<Include> includes = new ArrayList<Include>();
-  private final List<IncludeAnnotations> includeAnnotations = new ArrayList<IncludeAnnotations>();
-  private final List<CsdlAnnotation> annotations = new ArrayList<CsdlAnnotation>();
+  private final List<Include> includes = new ArrayList<>();
+  private final List<IncludeAnnotations> includeAnnotations = new ArrayList<>();
+  private final List<CsdlAnnotation> annotations = new ArrayList<>();
 
   @Override
   public List<CsdlAnnotation> getAnnotations() {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/CsdlTypeValidator.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/CsdlTypeValidator.java
index af35bc6..c1c822d 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/CsdlTypeValidator.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/CsdlTypeValidator.java
@@ -40,17 +40,17 @@
 
 public class CsdlTypeValidator {
 
-  private Map<String, String> aliasNamespaceMap = new HashMap<String, String>();
+  private Map<String, String> aliasNamespaceMap = new HashMap<>();
   private Map<FullQualifiedName, CsdlEntityContainer> csdlContainersMap = 
-      new HashMap<FullQualifiedName, CsdlEntityContainer>();
+      new HashMap<>();
   private Map<FullQualifiedName, CsdlEntityType> csdlEntityTypesMap = 
-      new HashMap<FullQualifiedName, CsdlEntityType>();
+      new HashMap<>();
   private Map<FullQualifiedName, CsdlComplexType> csdlComplexTypesMap = 
-      new HashMap<FullQualifiedName, CsdlComplexType>();
+      new HashMap<>();
   private Map<FullQualifiedName, CsdlAction> csdlActionsMap = 
-      new HashMap<FullQualifiedName, CsdlAction>();
+      new HashMap<>();
   private Map<FullQualifiedName, CsdlFunction> csdlFunctionsMap = 
-      new HashMap<FullQualifiedName, CsdlFunction>();
+      new HashMap<>();
   private static final String V4_SCHEMA_XMLNS = 
 		  "http://docs.oasis-open.org/odata/ns/edm";
   
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/EdmTypeValidator.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/EdmTypeValidator.java
index 236e18e..9b21ea1 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/EdmTypeValidator.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/metadatavalidator/EdmTypeValidator.java
@@ -37,15 +37,15 @@
 
 public class EdmTypeValidator {
   
-  private Map<String, String> aliasNamespaceMap = new HashMap<String, String>();
+  private Map<String, String> aliasNamespaceMap = new HashMap<>();
   private Map<FullQualifiedName, EdmEntityContainer> edmContainersMap = 
-      new HashMap<FullQualifiedName, EdmEntityContainer>();
+      new HashMap<>();
   private Map<FullQualifiedName, EdmEntityType> edmEntityTypesMap = 
-      new HashMap<FullQualifiedName, EdmEntityType>();
+      new HashMap<>();
   private Map<FullQualifiedName, EdmComplexType> edmComplexTypesMap = 
-      new HashMap<FullQualifiedName, EdmComplexType>();
+      new HashMap<>();
   private Map<FullQualifiedName, EdmFunction> edmFunctionsMap = 
-      new HashMap<FullQualifiedName, EdmFunction>();
+      new HashMap<>();
 
   /**
    * 
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomDeserializer.java
index 6930f87..a1b25a5 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomDeserializer.java
@@ -204,7 +204,7 @@
   private void fromCollection(final Valuable valuable, final XMLEventReader reader, final StartElement start,
       final EdmTypeInfo typeInfo) throws XMLStreamException, EdmPrimitiveTypeException {
 
-    List<Object> values = new ArrayList<Object>();
+    List<Object> values = new ArrayList<>();
     ValueType valueType = ValueType.COLLECTION_PRIMITIVE;
 
     final EdmTypeInfo type = typeInfo == null ? null :
@@ -372,9 +372,7 @@
       final XMLEventReader reader = getReader(input);
       final StartElement start = skipBeforeFirstStartElement(reader);
       return getContainer(start, property(reader, start));
-    } catch (XMLStreamException e) {
-      throw new ODataDeserializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataDeserializerException(e);
     }
   }
@@ -555,7 +553,7 @@
   private void properties(final XMLEventReader reader, final StartElement start, final Entity entity)
       throws XMLStreamException, EdmPrimitiveTypeException {
 
-    final Map<String, List<Annotation>> annotations = new HashMap<String, List<Annotation>>();
+    final Map<String, List<Annotation>> annotations = new HashMap<>();
 
     boolean foundEndProperties = false;
     while (reader.hasNext() && !foundEndProperties) {
@@ -741,9 +739,7 @@
       } else {
         return getContainer(start, entity);
       }
-    } catch (XMLStreamException e) {
-      throw new ODataDeserializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataDeserializerException(e);
     }
   }
@@ -829,9 +825,7 @@
       final XMLEventReader reader = getReader(input);
       final StartElement start = skipBeforeFirstStartElement(reader);
       return getContainer(start, entitySet(reader, start));
-    } catch (XMLStreamException e) {
-      throw new ODataDeserializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataDeserializerException(e);
     }
   }
@@ -925,7 +919,7 @@
     final Attribute context = start.getAttributeByName(contextQName);
     final Attribute metadataETag = start.getAttributeByName(metadataEtagQName);
 
-    return new ResWrap<T>(
+    return new ResWrap<>(
         context == null ? null : URI.create(context.getValue()),
             metadataETag == null ? null : metadataETag.getValue(),
                 object);
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomGeoValueDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomGeoValueDeserializer.java
index 74ad5c9..c7ec4ba 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomGeoValueDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomGeoValueDeserializer.java
@@ -49,7 +49,7 @@
   private List<Point> points(final XMLEventReader reader, final StartElement start,
       final EdmPrimitiveTypeKind type, final SRID srid) throws XMLStreamException {
 
-    final List<Point> result = new ArrayList<Point>();
+    final List<Point> result = new ArrayList<>();
 
     boolean foundEndProperty = false;
     while (reader.hasNext() && !foundEndProperty) {
@@ -142,7 +142,7 @@
   private MultiLineString multiLineString(final XMLEventReader reader, final StartElement start,
       final EdmPrimitiveTypeKind type, final SRID srid) throws XMLStreamException {
 
-    final List<LineString> lineStrings = new ArrayList<LineString>();
+    final List<LineString> lineStrings = new ArrayList<>();
 
     boolean foundEndProperty = false;
     while (reader.hasNext() && !foundEndProperty) {
@@ -163,7 +163,7 @@
   private MultiPolygon multiPolygon(final XMLEventReader reader, final StartElement start,
       final EdmPrimitiveTypeKind type, final SRID srid) throws XMLStreamException {
 
-    final List<Polygon> polygons = new ArrayList<Polygon>();
+    final List<Polygon> polygons = new ArrayList<>();
 
     boolean foundEndProperty = false;
     while (reader.hasNext() && !foundEndProperty) {
@@ -184,7 +184,7 @@
   private GeospatialCollection collection(final XMLEventReader reader, final StartElement start,
       final EdmPrimitiveTypeKind type, final SRID srid) throws XMLStreamException {
 
-    final List<Geospatial> geospatials = new ArrayList<Geospatial>();
+    final List<Geospatial> geospatials = new ArrayList<>();
 
     boolean foundEndCollection = false;
     while (reader.hasNext() && !foundEndCollection) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomSerializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomSerializer.java
index 4a2f840..ea058de 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomSerializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/AtomSerializer.java
@@ -213,7 +213,7 @@
   
   private void writeNavigationLinks(final XMLStreamWriter writer, final List<Link> links)
       throws XMLStreamException, EdmPrimitiveTypeException {
-    final Map<String, List<String>> entitySetLinks = new HashMap<String, List<String>>();
+    final Map<String, List<String>> entitySetLinks = new HashMap<>();
 
     for (Link link : links) {
     
@@ -264,7 +264,7 @@
           if (entitySetLinks.containsKey(link.getTitle())) {
             uris = entitySetLinks.get(link.getTitle());
           } else {
-            uris = new ArrayList<String>();
+            uris = new ArrayList<>();
             entitySetLinks.put(link.getTitle(), uris);
           }
           if (link.getHref() != null) {
@@ -637,9 +637,7 @@
       } else if (obj instanceof Link) {
         link(writer, (Link) obj);
       }
-    } catch (final XMLStreamException e) {
-      throw new ODataSerializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (final XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataSerializerException(e);
     }
   }
@@ -676,9 +674,7 @@
       } else if (obj instanceof URI) {
         reference(writer, (ResWrap<URI>) container);
       }
-    } catch (final XMLStreamException e) {
-      throw new ODataSerializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (final XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataSerializerException(e);
     }
   }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ClientODataDeserializerImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ClientODataDeserializerImpl.java
index 9d02bab..a7c0e94 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ClientODataDeserializerImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ClientODataDeserializerImpl.java
@@ -149,7 +149,7 @@
 
 	private List<List<String>> getAllSchemaNameSpace(InputStream inputStream)
 			throws ParserConfigurationException, SAXException, IOException{
-		List<List<String>> schemaNameSpaces = new ArrayList <List<String>>();
+		List<List<String>> schemaNameSpaces = new ArrayList <>();
 		
 		DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
 		dbFactory.setFeature(
@@ -180,7 +180,7 @@
 		
 		for (int temp = 0; temp < nList.getLength(); temp++) {
 			Node nNode = nList.item(temp);
-			List<String> nameSpaces = new ArrayList <String>();
+			List<String> nameSpaces = new ArrayList <>();
 			if (nNode.getNodeType() == Node.ELEMENT_NODE) {
 				Element eElement = (Element) nNode;
 				NamedNodeMap attributes = eElement.getAttributes();
@@ -212,16 +212,14 @@
           || contentType.isCompatible(ContentType.APPLICATION_ATOM_XML) ?
           new AtomDeserializer().delta(input) :
           new JsonDeltaDeserializer(false).toDelta(input);
-    } catch (final XMLStreamException e) {
-      throw new ODataDeserializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (final XMLStreamException | EdmPrimitiveTypeException e) {
       throw new ODataDeserializerException(e);
     }
   }
 
   @Override
   public List<CsdlSchema> fetchTermDefinitionSchema(List<InputStream> input) {
-    List<CsdlSchema> schemas = new ArrayList<CsdlSchema>();
+    List<CsdlSchema> schemas = new ArrayList<>();
     try {
       for (InputStream stream : input) {
         ClientCsdlEdmx edmx = getXmlMapper().readValue(stream, ClientCsdlEdmx.class);
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ContextURLParser.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ContextURLParser.java
index 873ca4c..4c0a5a7 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ContextURLParser.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ContextURLParser.java
@@ -79,7 +79,7 @@
       } else {
         firstToken = isEntity ? rest : StringUtils.substringBeforeLast(rest, ")") + ")";
 
-        final List<String> parts = new ArrayList<String>();
+        final List<String> parts = new ArrayList<>();
         for (String split : firstToken.split("\\)/")) {
           parts.add(split.replaceAll("\\(.*", ""));
         }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeltaDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeltaDeserializer.java
index ef9c054..c9fbe95 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeltaDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeltaDeserializer.java
@@ -86,7 +86,7 @@
       }
     }
 
-    return new ResWrap<Delta>(contextURL, null, delta);
+    return new ResWrap<>(contextURL, null, delta);
   }
 
   public ResWrap<Delta> toDelta(final InputStream input) throws ODataDeserializerException {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeserializer.java
index b2cfd49..efd2963 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonDeserializer.java
@@ -222,7 +222,7 @@
 
     final EdmTypeInfo typeInfo = typeExpression == null ? null :
       new EdmTypeInfo.Builder().setTypeExpression(typeExpression).build();
-    return new SimpleEntry<PropertyType, EdmTypeInfo>(type, typeInfo);
+    return new SimpleEntry<>(type, typeInfo);
   }
 
   private EdmPrimitiveTypeKind guessPrimitiveTypeKind(final JsonNode node) {
@@ -299,7 +299,7 @@
       throws IOException, EdmPrimitiveTypeException {
 
     final ComplexValue complexValue = new ComplexValue();
-    final Set<String> toRemove = new HashSet<String>();
+    final Set<String> toRemove = new HashSet<>();
     for (final Iterator<Map.Entry<String, JsonNode>> itor = node.fields(); itor.hasNext();) {
       final Map.Entry<String, JsonNode> field = itor.next();
 
@@ -314,7 +314,7 @@
   private void fromCollection(final Valuable valuable, final Iterator<JsonNode> nodeItor, final EdmTypeInfo typeInfo,
       final ObjectCodec codec) throws IOException, EdmPrimitiveTypeException {
 
-    final List<Object> values = new ArrayList<Object>();
+    final List<Object> values = new ArrayList<>();
     ValueType valueType = ValueType.COLLECTION_PRIMITIVE;
 
     final EdmTypeInfo type = typeInfo == null ? null
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntityDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntityDeserializer.java
index 53a0cab..b778407 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntityDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntityDeserializer.java
@@ -140,9 +140,9 @@
       tree.remove(Constants.JSON_MEDIA_ETAG);
     }
 
-    final Set<String> toRemove = new HashSet<String>();
+    final Set<String> toRemove = new HashSet<>();
 
-    final Map<String, List<Annotation>> annotations = new HashMap<String, List<Annotation>>();
+    final Map<String, List<Annotation>> annotations = new HashMap<>();
     for (final Iterator<Map.Entry<String, JsonNode>> itor = tree.fields(); itor.hasNext();) {
       final Map.Entry<String, JsonNode> field = itor.next();
       final Matcher customAnnotation = CUSTOM_ANNOTATION.matcher(field.getKey());
@@ -236,7 +236,7 @@
       throw new IOException(e);
     }
 
-    return new ResWrap<Entity>(contextURL, metadataETag, entity);
+    return new ResWrap<>(contextURL, metadataETag, entity);
   }
   
   private Link getOrCreateMediaLink(final Entity entity, final String name) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntitySetDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntitySetDeserializer.java
index d54b98b..7659055 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntitySetDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonEntitySetDeserializer.java
@@ -101,7 +101,7 @@
       }
       tree.remove(Constants.VALUE);
     }
-    final Set<String> toRemove = new HashSet<String>();
+    final Set<String> toRemove = new HashSet<>();
     // any remaining entry is supposed to be an annotation or is ignored
     for (final Iterator<Map.Entry<String, JsonNode>> itor = tree.fields(); itor.hasNext();) {
       final Map.Entry<String, JsonNode> field = itor.next();
@@ -127,6 +127,6 @@
       }
     }
     tree.remove(toRemove);
-    return new ResWrap<EntityCollection>(contextURL, metadataETag, entitySet);
+    return new ResWrap<>(contextURL, metadataETag, entitySet);
   }
 }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonGeoValueDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonGeoValueDeserializer.java
index 3b967ae..818e61f 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonGeoValueDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonGeoValueDeserializer.java
@@ -65,7 +65,7 @@
     final MultiPoint multiPoint;
 
     if (itor.hasNext()) {
-      final List<Point> points = new ArrayList<Point>();
+      final List<Point> points = new ArrayList<>();
       while (itor.hasNext()) {
         final Iterator<JsonNode> mpItor = itor.next().elements();
         points.add(point(mpItor, type, srid));
@@ -82,7 +82,7 @@
     final LineString lineString;
 
     if (itor.hasNext()) {
-      final List<Point> points = new ArrayList<Point>();
+      final List<Point> points = new ArrayList<>();
       while (itor.hasNext()) {
         final Iterator<JsonNode> mpItor = itor.next().elements();
         points.add(point(mpItor, type, srid));
@@ -101,7 +101,7 @@
     final MultiLineString multiLineString;
 
     if (itor.hasNext()) {
-      final List<LineString> lineStrings = new ArrayList<LineString>();
+      final List<LineString> lineStrings = new ArrayList<>();
       while (itor.hasNext()) {
         final Iterator<JsonNode> mlsItor = itor.next().elements();
         lineStrings.add(lineString(mlsItor, type, srid));
@@ -119,7 +119,7 @@
     if (itor.hasNext()) {
       final Iterator<JsonNode> extItor = itor.next().elements();
       if (extItor.hasNext()) {
-        extPoints = new ArrayList<Point>();
+        extPoints = new ArrayList<>();
         while (extItor.hasNext()) {
           final Iterator<JsonNode> mpItor = extItor.next().elements();
           extPoints.add(point(mpItor, type, srid));
@@ -131,7 +131,7 @@
     while (itor.hasNext()) {
       final Iterator<JsonNode> intItor = itor.next().elements();
       if (intItor.hasNext()) {
-        List<Point> intPoints = new ArrayList<Point>();
+        List<Point> intPoints = new ArrayList<>();
         while (intItor.hasNext()) {
           final Iterator<JsonNode> mpItor = intItor.next().elements();
           intPoints.add(point(mpItor, type, srid));
@@ -148,7 +148,7 @@
     final MultiPolygon multiPolygon;
 
     if (itor.hasNext()) {
-      final List<Polygon> polygons = new ArrayList<Polygon>();
+      final List<Polygon> polygons = new ArrayList<>();
       while (itor.hasNext()) {
         final Iterator<JsonNode> mpItor = itor.next().elements();
         polygons.add(polygon(mpItor, type, srid));
@@ -167,7 +167,7 @@
     final GeospatialCollection collection;
 
     if (itor.hasNext()) {
-      final List<Geospatial> geospatials = new ArrayList<Geospatial>();
+      final List<Geospatial> geospatials = new ArrayList<>();
 
       while (itor.hasNext()) {
         final JsonNode geo = itor.next();
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDeserializer.java
index 65a473e..2584db9 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDeserializer.java
@@ -61,7 +61,7 @@
         error.setTarget(errorNode.get(Constants.ERROR_TARGET).textValue());
       }
       if (errorNode.hasNonNull(Constants.ERROR_DETAILS)) {
-        List<ODataErrorDetail> details = new ArrayList<ODataErrorDetail>();
+        List<ODataErrorDetail> details = new ArrayList<>();
         JsonODataErrorDetailDeserializer detailDeserializer = new JsonODataErrorDetailDeserializer(serverMode);
         for (JsonNode jsonNode : errorNode.get(Constants.ERROR_DETAILS)) {
           details.add(detailDeserializer.doDeserialize(jsonNode.traverse(parser.getCodec()))
@@ -71,7 +71,7 @@
         error.setDetails(details);
       }
       if (errorNode.hasNonNull(Constants.ERROR_INNERERROR)) {
-        HashMap<String, String> innerErrorMap = new HashMap<String, String>();
+        HashMap<String, String> innerErrorMap = new HashMap<>();
         final JsonNode innerError = errorNode.get(Constants.ERROR_INNERERROR);
         for (final Iterator<String> itor = innerError.fieldNames(); itor.hasNext();) {
           final String keyTmp = itor.next();
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDetailDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDetailDeserializer.java
index 95657e9..a8ddfc0 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDetailDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonODataErrorDetailDeserializer.java
@@ -53,6 +53,6 @@
       error.setTarget(errorNode.get(Constants.ERROR_TARGET).textValue());
     }
 
-    return new ResWrap<ODataErrorDetail>((URI) null, null, error);
+    return new ResWrap<>((URI) null, null, error);
   }
 }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonPropertyDeserializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonPropertyDeserializer.java
index af21df7..f3ce3cb 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonPropertyDeserializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonPropertyDeserializer.java
@@ -96,7 +96,7 @@
       tree.remove(Constants.VALUE);
     }
 
-    Set<String> toRemove = new HashSet<String>();
+    Set<String> toRemove = new HashSet<>();
     // any remaining entry is supposed to be an annotation or is ignored
     for (final Iterator<Map.Entry<String, JsonNode>> itor = tree.fields(); itor.hasNext();) {
       final Map.Entry<String, JsonNode> field = itor.next();
@@ -122,6 +122,6 @@
       }
     }
     tree.remove(toRemove);
-    return new ResWrap<Property>(contextURL, metadataETag, property);
+    return new ResWrap<>(contextURL, metadataETag, property);
   }
 }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonSerializer.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonSerializer.java
index 57931eb..cd0d033 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonSerializer.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/JsonSerializer.java
@@ -77,8 +77,7 @@
 
   @Override
   public <T> void write(final Writer writer, final T obj) throws ODataSerializerException {
-    try {
-      final JsonGenerator json = new JsonFactory().createGenerator(writer);
+    try (final JsonGenerator json = new JsonFactory().createGenerator(writer)) {
       if (obj instanceof EntityCollection) {
         new JsonEntitySetSerializer(serverMode, contentType).doSerialize((EntityCollection) obj, json);
       } else if (obj instanceof Entity) {
@@ -89,9 +88,7 @@
         link((Link) obj, json);
       }
       json.flush();
-    } catch (final IOException e) {
-      throw new ODataSerializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (final IOException | EdmPrimitiveTypeException e) {
       throw new ODataSerializerException(e);
     }
   }
@@ -111,8 +108,7 @@
   @Override
   public <T> void write(final Writer writer, final ResWrap<T> container) throws ODataSerializerException {
     final T obj = container == null ? null : container.getPayload();
-    try {
-      final JsonGenerator json = new JsonFactory().createGenerator(writer);
+    try (final JsonGenerator json = new JsonFactory().createGenerator(writer)) {
       if (obj instanceof EntityCollection) {
         new JsonEntitySetSerializer(serverMode, contentType).doContainerSerialize(
             (ResWrap<EntityCollection>) container, json);
@@ -126,9 +122,7 @@
         reference((ResWrap<URI>) container, json);
       }
       json.flush();
-    } catch (final IOException e) {
-      throw new ODataSerializerException(e);
-    } catch (final EdmPrimitiveTypeException e) {
+    } catch (final IOException | EdmPrimitiveTypeException e) {
       throw new ODataSerializerException(e);
     }
   }
@@ -152,7 +146,7 @@
   protected void clientLinks(final Linked linked, final JsonGenerator jgen)
       throws IOException, EdmPrimitiveTypeException {
 
-    final Map<String, List<String>> entitySetLinks = new HashMap<String, List<String>>();
+    final Map<String, List<String>> entitySetLinks = new HashMap<>();
     for (Link link : linked.getNavigationLinks()) {
       for (Annotation annotation : link.getAnnotations()) {
         valuable(jgen, annotation, link.getTitle() + "@" + annotation.getTerm());
@@ -163,7 +157,7 @@
         if (entitySetLinks.containsKey(link.getTitle())) {
           uris = entitySetLinks.get(link.getTitle());
         } else {
-          uris = new ArrayList<String>();
+          uris = new ArrayList<>();
           entitySetLinks.put(link.getTitle(), uris);
         }
         if (link.getHref() != null && !link.getHref().isEmpty()) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataBinderImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataBinderImpl.java
index 7d35668..dfd3d41 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataBinderImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataBinderImpl.java
@@ -343,7 +343,7 @@
     } else if (value.isPrimitive()) {
       valueResource = value.asPrimitive().toValue();
     } else if (value.isComplex()) {
-      List<Property> complexProperties = new ArrayList<Property>();
+      List<Property> complexProperties = new ArrayList<>();
       for (final ClientProperty propertyValue : value.asComplex()) {
         complexProperties.add(getProperty(propertyValue));
       }
@@ -356,7 +356,7 @@
 
     } else if (value.isCollection()) {
       final ClientCollectionValue<? extends ClientValue> _value = value.asCollection();
-      ArrayList<Object> lcValueResource = new ArrayList<Object>();
+      ArrayList<Object> lcValueResource = new ArrayList<>();
 
       for (final ClientValue collectionValue : _value) {
         lcValueResource.add(getValue(collectionValue));
@@ -703,7 +703,7 @@
       entity.setMediaETag(resource.getPayload().getMediaETag());
     }
 
-    Map<String, Integer> countMap = new HashMap<String, Integer>();
+    Map<String, Integer> countMap = new HashMap<>();
     for (final Property property : resource.getPayload().getProperties()) {
       EdmType propertyType = null;
       if (edmType instanceof EdmEntityType) {
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataMetadataValidationImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataMetadataValidationImpl.java
index acbb040..4f556ea 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataMetadataValidationImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataMetadataValidationImpl.java
@@ -44,11 +44,11 @@
 
   @Override
   public void validateMetadata(Edm edm) {
-    Map<FullQualifiedName, EdmEntityType> edmEntityTypesMap = new HashMap<FullQualifiedName, EdmEntityType>();
-    Map<FullQualifiedName, EdmComplexType> edmComplexTypesMap = new HashMap<FullQualifiedName, EdmComplexType>();
-    Map<FullQualifiedName, EdmFunction> edmFunctionsMap = new HashMap<FullQualifiedName, EdmFunction>();
-    Map<FullQualifiedName, EdmEntityContainer> edmContainersMap = new HashMap<FullQualifiedName, EdmEntityContainer>();
-    Map<String, String> aliasNamespaceMap = new HashMap<String, String>();
+    Map<FullQualifiedName, EdmEntityType> edmEntityTypesMap = new HashMap<>();
+    Map<FullQualifiedName, EdmComplexType> edmComplexTypesMap = new HashMap<>();
+    Map<FullQualifiedName, EdmFunction> edmFunctionsMap = new HashMap<>();
+    Map<FullQualifiedName, EdmEntityContainer> edmContainersMap = new HashMap<>();
+    Map<String, String> aliasNamespaceMap = new HashMap<>();
     List<EdmSchema> edmSchemas = edm.getSchemas();
     for (EdmSchema edmSchema : edmSchemas) {
       List<EdmEntityType> edmEntityTypes = edmSchema.getEntityTypes();
@@ -75,13 +75,13 @@
 
   @Override
   public void validateMetadata(XMLMetadata xmlMetadata) {
-    Map<FullQualifiedName, CsdlEntityType> csdlEntityTypesMap = new HashMap<FullQualifiedName, CsdlEntityType>();
-    Map<FullQualifiedName, CsdlComplexType> csdlComplexTypesMap = new HashMap<FullQualifiedName, CsdlComplexType>();
-    Map<FullQualifiedName, CsdlAction> csdlActionsMap = new HashMap<FullQualifiedName, CsdlAction>();
-    Map<FullQualifiedName, CsdlFunction> csdlFunctionsMap = new HashMap<FullQualifiedName, CsdlFunction>();
+    Map<FullQualifiedName, CsdlEntityType> csdlEntityTypesMap = new HashMap<>();
+    Map<FullQualifiedName, CsdlComplexType> csdlComplexTypesMap = new HashMap<>();
+    Map<FullQualifiedName, CsdlAction> csdlActionsMap = new HashMap<>();
+    Map<FullQualifiedName, CsdlFunction> csdlFunctionsMap = new HashMap<>();
     Map<FullQualifiedName, CsdlEntityContainer> csdlContainersMap = 
-        new HashMap<FullQualifiedName, CsdlEntityContainer>();
-    Map<String, String> aliasNamespaceMap = new HashMap<String, String>();
+        new HashMap<>();
+    Map<String, String> aliasNamespaceMap = new HashMap<>();
     List<CsdlSchema> csdlSchemas = xmlMetadata.getSchemas();
     for (CsdlSchema csdlSchema : csdlSchemas) {
       List<CsdlEntityType> csdlEntityTypes = csdlSchema.getEntityTypes();
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataReaderImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataReaderImpl.java
index cae81b2..26d5872 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataReaderImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/serialization/ODataReaderImpl.java
@@ -93,7 +93,7 @@
 
     try {
       if (ClientEntitySetIterator.class.isAssignableFrom(reference)) {
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             (URI) null,
             null,
             reference.cast(new ClientEntitySetIterator<ClientEntitySet, ClientEntity>(
@@ -101,24 +101,24 @@
       } else if (ClientEntitySet.class.isAssignableFrom(reference)) {
         final ResWrap<EntityCollection> resource = client.getDeserializer(ContentType.parse(format))
             .toEntitySet(src);
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             resource.getContextURL(),
             resource.getMetadataETag(),
             reference.cast(client.getBinder().getODataEntitySet(resource)));
       } else if (ClientEntity.class.isAssignableFrom(reference)) {
         final ResWrap<Entity> container = client.getDeserializer(ContentType.parse(format)).toEntity(src);
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             container.getContextURL(),
             container.getMetadataETag(),
             reference.cast(client.getBinder().getODataEntity(container)));
       } else if (ClientProperty.class.isAssignableFrom(reference)) {
         final ResWrap<Property> container = client.getDeserializer(ContentType.parse(format)).toProperty(src);
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             container.getContextURL(),
             container.getMetadataETag(),
             reference.cast(client.getBinder().getODataProperty(container)));
       } else if (ClientValue.class.isAssignableFrom(reference)) {
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             (URI) null,
             null,
             reference.cast(client.getObjectFactory().newPrimitiveValueBuilder().
@@ -127,19 +127,19 @@
                 setValue(IOUtils.toString(src)) // TODO: set correct value
                 .build()));
       } else if (XMLMetadata.class.isAssignableFrom(reference)) {
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             (URI) null,
             null,
             reference.cast(readMetadata(src)));
       } else if (ClientServiceDocument.class.isAssignableFrom(reference)) {
         final ResWrap<ServiceDocument> resource =
             client.getDeserializer(ContentType.parse(format)).toServiceDocument(src);
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             resource.getContextURL(),
             resource.getMetadataETag(),
             reference.cast(client.getBinder().getODataServiceDocument(resource.getPayload())));
       } else if (ODataError.class.isAssignableFrom(reference)) {
-        res = new ResWrap<T>(
+        res = new ResWrap<>(
             (URI) null,
             null,
             reference.cast(readError(src, ContentType.parse(format))));
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIBuilderImpl.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIBuilderImpl.java
index 7071d37..fade189 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIBuilderImpl.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIBuilderImpl.java
@@ -82,22 +82,22 @@
 
   private final Configuration configuration;
 
-  protected final List<Segment> segments = new ArrayList<Segment>();
+  protected final List<Segment> segments = new ArrayList<>();
 
   /**
    * Insertion-order map of query options.
    */
-  protected final Map<String, String> queryOptions = new LinkedHashMap<String, String>();
+  protected final Map<String, String> queryOptions = new LinkedHashMap<>();
 
   /**
    * Insertion-order map of custom query options.
    */
-  protected final Map<String, String> customQueryOptions = new LinkedHashMap<String, String>();
+  protected final Map<String, String> customQueryOptions = new LinkedHashMap<>();
   
   /**
    * Insertion-order map of parameter aliases.
    */
-  protected final Map<String, String> parameters = new LinkedHashMap<String, String>();
+  protected final Map<String, String> parameters = new LinkedHashMap<>();
 
   @Override
   public URIBuilder addQueryOption(final QueryOption option, final String value) {
@@ -301,7 +301,7 @@
     try {
       if ((customQueryOptions.size() + queryOptions.size() + parameters.size()) > 0) {
         segmentsBuilder.append("?");
-        List<NameValuePair> list1 = new LinkedList<NameValuePair>();
+        List<NameValuePair> list1 = new LinkedList<>();
         for (Map.Entry<String, String> option : queryOptions.entrySet()) {
           list1.add(new BasicNameValuePair("$" + option.getKey(), option.getValue()));
         }
@@ -372,7 +372,7 @@
   public URIBuilder appendKeySegment(final Map<String, Pair<EdmEnumType, String>> enumValues,
       final Map<String, Object> segmentValues) {
 
-    final Map<String, Object> values = new LinkedHashMap<String, Object>();
+    final Map<String, Object> values = new LinkedHashMap<>();
     for (Map.Entry<String, Pair<EdmEnumType, String>> entry : enumValues.entrySet()) {
       values.put(entry.getKey(), entry.getValue().getKey().toUriLiteral(entry.getValue().getValue()));
     }
@@ -453,7 +453,7 @@
   @Override
   public URIBuilder expandWithOptions(String expandItem, boolean pathRef,
       boolean pathCount, Map<QueryOption, Object> options) {
-    final Map<String, Object> _options = new LinkedHashMap<String, Object>();
+    final Map<String, Object> _options = new LinkedHashMap<>();
     for (Map.Entry<QueryOption, Object> entry : options.entrySet()) {
       _options.put("$" + entry.getKey().toString(), entry.getValue());
     }
diff --git a/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIUtils.java b/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIUtils.java
index e7cf3b1..cbc4618 100644
--- a/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIUtils.java
+++ b/lib/client-core/src/main/java/org/apache/olingo/client/core/uri/URIUtils.java
@@ -257,9 +257,7 @@
                                                                 ? quoteString((String) obj, singleQuoteEscape)
                                                                 : obj.toString();
       }
-    } catch (final EdmPrimitiveTypeException e) {
-      value = obj.toString();
-    } catch (final UnsupportedEncodingException e) {
+    } catch (final EdmPrimitiveTypeException | UnsupportedEncodingException e) {
       value = obj.toString();
     }
 
diff --git a/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/Annotatable.java b/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/Annotatable.java
index f42f10c..1e364d1 100644
--- a/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/Annotatable.java
+++ b/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/Annotatable.java
@@ -26,7 +26,7 @@
  */
 public abstract class Annotatable {
 
-  private final List<Annotation> annotations = new ArrayList<Annotation>();
+  private final List<Annotation> annotations = new ArrayList<>();
 
   /**
    * Get Annotations.
diff --git a/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/ComplexValue.java b/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/ComplexValue.java
index 523c938..7633997 100644
--- a/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/ComplexValue.java
+++ b/lib/commons-api/src/main/java/org/apache/olingo/commons/api/data/ComplexValue.java
@@ -26,7 +26,7 @@
  */
 public class ComplexValue extends Linked {
 
-  private final List<Property> value = new ArrayList<Property>();
+  private final List<Property> value = new ArrayList<>();
   
   private String typeName;
 
diff --git a/lib/server-core/src/main/java/org/apache/olingo/netty/server/core/ODataNettyHandlerImpl.java b/lib/server-core/src/main/java/org/apache/olingo/netty/server/core/ODataNettyHandlerImpl.java
index add6409..fd31f45 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/netty/server/core/ODataNettyHandlerImpl.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/netty/server/core/ODataNettyHandlerImpl.java
@@ -129,21 +129,19 @@
    * @param response
    */
   static void copyContent(final ReadableByteChannel input, final HttpResponse response) {
-    WritableByteChannel output = null;
-    try {
-      ByteBuffer inBuffer = ByteBuffer.allocate(COPY_BUFFER_SIZE);
-      output = Channels.newChannel(new ByteBufOutputStream(((HttpContent)response).content()));
-      while (input.read(inBuffer) > 0) {
-        inBuffer.flip();
-        output.write(inBuffer);
-        inBuffer.clear();
+    try (WritableByteChannel output = Channels.newChannel(new ByteBufOutputStream(((HttpContent)response).content()))){
+        ByteBuffer inBuffer = ByteBuffer.allocate(COPY_BUFFER_SIZE);
+        while (input.read(inBuffer) > 0) {
+          inBuffer.flip();
+          output.write(inBuffer);
+          inBuffer.clear();
+        }
+        closeStream(output);
+      } catch (IOException e) {
+        throw new ODataRuntimeException("Error on reading request content", e);
+      } finally {
+        closeStream(input);
       }
-    } catch (IOException e) {
-      throw new ODataRuntimeException("Error on reading request content", e);
-    } finally {
-      closeStream(input);
-      closeStream(output);
-    }
   }
 
   private static void closeStream(final Channel closeable) {
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java
index 7a632b1..5b1e7d2 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/ODataHttpHandlerImpl.java
@@ -179,10 +179,8 @@
   }
 
   static void copyContent(final ReadableByteChannel input, final HttpServletResponse servletResponse) {
-    WritableByteChannel output = null;
-    try {
+    try (WritableByteChannel output = Channels.newChannel(servletResponse.getOutputStream());) {
       ByteBuffer inBuffer = ByteBuffer.allocate(COPY_BUFFER_SIZE);
-      output = Channels.newChannel(servletResponse.getOutputStream());
       while (input.read(inBuffer) > 0) {
         inBuffer.flip();
         output.write(inBuffer);
@@ -192,7 +190,6 @@
       throw new ODataRuntimeException("Error on reading request content", e);
     } finally {
       closeStream(input);
-      closeStream(output);
     }
   }
   
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugResponseHelperImpl.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugResponseHelperImpl.java
index eaeef7f..115af4f 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugResponseHelperImpl.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugResponseHelperImpl.java
@@ -132,13 +132,10 @@
 
   private InputStream wrapInJson(final List<DebugTab> parts) throws IOException {
     OutputStream outputStream = null;
-
-    try {
-      CircleStreamBuffer csb = new CircleStreamBuffer();
-      outputStream = csb.getOutputStream();
-      // Create JSON generator (the object mapper is necessary to write expression trees).
-      JsonGenerator gen = new ObjectMapper().getFactory().createGenerator(outputStream);
-
+    CircleStreamBuffer csb = new CircleStreamBuffer();
+    outputStream = csb.getOutputStream();
+    // Create JSON generator (the object mapper is necessary to write expression trees).
+    try (JsonGenerator gen = new ObjectMapper().getFactory().createGenerator(outputStream)) {
       gen.writeStartObject();
       DebugTab requestInfo = parts.get(0);
       gen.writeFieldName(requestInfo.getName().toLowerCase(Locale.ROOT));
@@ -159,8 +156,6 @@
 
       gen.writeEndObject();
       gen.close();
-      outputStream.close();
-
       return csb.getInputStream();
     } finally {
       if (outputStream != null) {
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabUri.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabUri.java
index 2acbc48..daa4757 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabUri.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/debug/DebugTabUri.java
@@ -499,15 +499,14 @@
   public void appendHtml(final Writer writer) throws IOException {
     // factory for JSON generators (the object mapper is necessary to write expression trees)
     final JsonFactory jsonFactory = new ObjectMapper().getFactory();
-    JsonGenerator json;
-
     if (uriInfo.getKind() == UriInfoKind.resource) {
       writer.append("<h2>Resource Path</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendURIResourceParts(json, uriInfo.getUriResourceParts());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendURIResourceParts(json, uriInfo.getUriResourceParts());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     } else if (uriInfo.getKind() == UriInfoKind.crossjoin) {
       writer.append("<h2>Crossjoin EntitySet Names</h2>\n")
           .append("<ul>\n");
@@ -528,37 +527,41 @@
     if (uriInfo.getSearchOption() != null) {
       writer.append("<h2>Search Option</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendSearchJson(json, uriInfo.getSearchOption().getSearchExpression());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendSearchJson(json, uriInfo.getSearchOption().getSearchExpression());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     }
 
     if (uriInfo.getFilterOption() != null) {
       writer.append("<h2>Filter Option</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendExpressionJson(json, uriInfo.getFilterOption().getExpression());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendExpressionJson(json, uriInfo.getFilterOption().getExpression());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     }
 
     if (uriInfo.getOrderByOption() != null) {
       writer.append("<h2>OrderBy Option</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendOrderByItemsJson(json, uriInfo.getOrderByOption().getOrders());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendOrderByItemsJson(json, uriInfo.getOrderByOption().getOrders());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     }
 
     if (uriInfo.getExpandOption() != null) {
       writer.append("<h2>Expand Option</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendExpandedPropertiesJson(json, uriInfo.getExpandOption().getExpandItems());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendExpandedPropertiesJson(json, uriInfo.getExpandOption().getExpandItems());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     }
 
     if (uriInfo.getSelectOption() != null) {
@@ -573,10 +576,11 @@
     if (uriInfo.getApplyOption() != null) {
       writer.append("<h2>Apply Option</h2>\n")
           .append("<ul>\n<li class=\"json\">");
-      json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter();
-      appendApplyItemsJson(json, uriInfo.getApplyOption().getApplyItems());
-      json.close();
-      writer.append("\n</li>\n</ul>\n");
+      try (JsonGenerator json = jsonFactory.createGenerator(writer).useDefaultPrettyPrinter()) {
+        appendApplyItemsJson(json, uriInfo.getApplyOption().getApplyItems());
+        json.close();
+        writer.append("\n</li>\n</ul>\n");
+      }
     }
 
     if (uriInfo.getCountOption() != null
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/AsyncResponseSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/AsyncResponseSerializer.java
index ac779fc..dd2129c 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/AsyncResponseSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/AsyncResponseSerializer.java
@@ -84,12 +84,14 @@
     InputStream input = response.getContent();
     if (input != null) {
       ByteBuffer inBuffer = ByteBuffer.allocate(BUFFER_SIZE);
-      ReadableByteChannel ic = Channels.newChannel(input);
-      WritableByteChannel oc = Channels.newChannel(buffer);
-      while (ic.read(inBuffer) > 0) {
-        inBuffer.flip();
-        oc.write(inBuffer);
-        inBuffer.rewind();
+      try (ReadableByteChannel ic = Channels.newChannel(input)) {
+        try (WritableByteChannel oc = Channels.newChannel(buffer)) {
+          while (ic.read(inBuffer) > 0) {
+            inBuffer.flip();
+            oc.write(inBuffer);
+            inBuffer.rewind();
+          }
+        }
       }
     }
   }
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/BatchResponseSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/BatchResponseSerializer.java
index 067fe95..ef75fdf 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/BatchResponseSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/BatchResponseSerializer.java
@@ -258,12 +258,14 @@
             res.write(Channels.newChannel(output));
             }
         } else {
-          ReadableByteChannel ic = Channels.newChannel(response.getContent());
-          WritableByteChannel oc = Channels.newChannel(output);
-          while (ic.read(inBuffer) > 0) {
-            inBuffer.flip();
-            oc.write(inBuffer);
-            inBuffer.rewind();
+          try (WritableByteChannel oc = Channels.newChannel(output)) {
+            try (ReadableByteChannel ic = Channels.newChannel(response.getContent())) {
+              while (ic.read(inBuffer) > 0) {
+                inBuffer.flip();
+                oc.write(inBuffer);
+                inBuffer.rewind();
+              }
+            }
           }
         }
         return output.toByteArray();
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/EdmAssistedJsonSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/EdmAssistedJsonSerializer.java
index b9cbbd6..b5ef2f9 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/EdmAssistedJsonSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/EdmAssistedJsonSerializer.java
@@ -95,10 +95,10 @@
         contextURL).toASCIIString();
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       if (obj instanceof AbstractEntityCollection) {
         doSerialize(entityType, (AbstractEntityCollection) obj, contextURLString, metadataETag, json);
       } else if (obj instanceof Entity) {
@@ -108,7 +108,6 @@
       }
       json.flush();
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException = new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/JsonDeltaSerializerWithNavigations.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/JsonDeltaSerializerWithNavigations.java
index e803f89..52bb217 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/JsonDeltaSerializerWithNavigations.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/JsonDeltaSerializerWithNavigations.java
@@ -89,28 +89,27 @@
     OutputStream outputStream = null;
     SerializerException cachedException = null;
     boolean pagination = false;
-    try {
+    
       CircleStreamBuffer buffer = new CircleStreamBuffer();
       outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
-      json.writeStartObject();
+      try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
+        json.writeStartObject();
 
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      writeContextURL(contextURL, json);
+        final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+        writeContextURL(contextURL, json);
 
-      if (options != null && options.getCount() != null && options.getCount().getValue()) {
-        writeInlineCount(delta.getCount(), json);
-      }
-      json.writeFieldName(Constants.VALUE);
-      writeEntitySet(metadata, referencedEntityType, delta, options, json);
+        if (options != null && options.getCount() != null && options.getCount().getValue()) {
+          writeInlineCount(delta.getCount(), json);
+        }
+        json.writeFieldName(Constants.VALUE);
+        writeEntitySet(metadata, referencedEntityType, delta, options, json);
 
-      pagination = writeNextLink(delta, json);
-      writeDeltaLink(delta, json, pagination);
+        pagination = writeNextLink(delta, json);
+        writeDeltaLink(delta, json, pagination);
 
-      json.close();
-      outputStream.close();
-      return SerializerResultImpl.with().content(buffer.getInputStream()).build();
-    } catch (final IOException e) {
+        json.close();
+        return SerializerResultImpl.with().content(buffer.getInputStream()).build();
+      } catch (final IOException e) {
       cachedException =
           new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
       throw cachedException;
diff --git a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
index 65f9675..a26bbfd 100644
--- a/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
+++ b/lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java
@@ -136,19 +136,17 @@
     OutputStream outputStream = null;
     SerializerException cachedException = null;
 
-    try {
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       new ServiceDocumentJsonSerializer(metadata, serviceRoot, isODataMetadataNone).writeServiceDocument(json);
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
-      cachedException =
-          new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
-      throw cachedException;
+    cachedException =
+        new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
+    throw cachedException;
     } finally {
       closeCircleStreamBufferOutput(outputStream, cachedException);
     }
@@ -159,14 +157,12 @@
     OutputStream outputStream = null;
     SerializerException cachedException = null;
 
-    try {
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       new MetadataDocumentJsonSerializer(serviceMetadata).writeMetadataDocument(json);
-
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -181,14 +177,13 @@
   public SerializerResult error(final ODataServerError error) throws SerializerException {
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       new ODataErrorSerializer().writeErrorDocument(json, error);
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -206,10 +201,10 @@
     OutputStream outputStream = null;
     SerializerException cachedException = null;
     boolean pagination = false;
-    try {
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       json.writeStartObject();
 
       final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
@@ -233,13 +228,8 @@
       writeDeltaLink(entitySet, json, pagination);
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
-    } catch (final IOException e) {
-      cachedException =
-          new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
-      throw cachedException;
-    } catch (DecoderException e) {
+    } catch (final IOException | DecoderException e) {
       cachedException =
           new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
       throw cachedException;
@@ -286,11 +276,7 @@
       writeNextLink(entitySet, json, pagination);
 
       json.close();
-    } catch (final IOException e) {
-      cachedException =
-          new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
-      throw cachedException;
-    } catch (DecoderException e) {
+    } catch (final IOException | DecoderException e) {
       cachedException =
           new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
       throw cachedException;
@@ -302,11 +288,11 @@
       final Entity entity, final EntitySerializerOptions options) throws SerializerException {
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       String name =  contextURL == null ? null:contextURL.getEntitySetOrSingletonOrType();
       writeEntity(metadata, entityType, entity, contextURL,
           options == null ? null : options.getExpand(),
@@ -317,16 +303,11 @@
           json);
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
-    } catch (final IOException e) {
+    } catch (final IOException | DecoderException e) {
       cachedException =
           new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
       throw cachedException;
-    } catch (DecoderException e) { 
-      cachedException =
-        new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
-      throw cachedException;
     } finally {
       closeCircleStreamBufferOutput(outputStream, cachedException);
     }
@@ -1122,11 +1103,11 @@
       final Property property, final PrimitiveSerializerOptions options) throws SerializerException {
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       json.writeStartObject();
       writeContextURL(contextURL, json);
       writeMetadataETag(metadata, json);
@@ -1145,7 +1126,6 @@
       json.writeEndObject();
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -1227,11 +1207,11 @@
       final Property property, final PrimitiveSerializerOptions options) throws SerializerException {
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       json.writeStartObject();
       writeContextURL(contextURL, json);
       writeMetadataETag(metadata, json);
@@ -1249,7 +1229,6 @@
       json.writeEndObject();
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -1265,11 +1244,11 @@
       final Property property, final ComplexSerializerOptions options) throws SerializerException {
     OutputStream outputStream = null;
     SerializerException cachedException = null;
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      outputStream = buffer.getOutputStream();
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    outputStream = buffer.getOutputStream();
+    try (JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       json.writeStartObject();
       writeContextURL(contextURL, json);
       writeMetadataETag(metadata, json);
@@ -1294,7 +1273,6 @@
       json.writeEndObject();
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -1311,12 +1289,12 @@
     OutputStream outputStream = null;
     SerializerException cachedException = null;
 
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      final UriHelper uriHelper = new UriHelperImpl();
-      outputStream = buffer.getOutputStream();
-      final JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    final UriHelper uriHelper = new UriHelperImpl();
+    outputStream = buffer.getOutputStream();
+    try (final JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
 
       json.writeStartObject();
       writeContextURL(contextURL, json);
@@ -1324,7 +1302,6 @@
       json.writeEndObject();
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
@@ -1343,12 +1320,11 @@
     SerializerException cachedException = null;
     boolean pagination = false ;
 
-    try {
-      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
-      CircleStreamBuffer buffer = new CircleStreamBuffer();
-      final UriHelper uriHelper = new UriHelperImpl();
-      outputStream = buffer.getOutputStream();
-      final JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+    final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+    CircleStreamBuffer buffer = new CircleStreamBuffer();
+    final UriHelper uriHelper = new UriHelperImpl();
+    outputStream = buffer.getOutputStream();
+    try (final JsonGenerator json = new JsonFactory().createGenerator(outputStream)) {
       json.writeStartObject();
 
       writeContextURL(contextURL, json);
@@ -1369,7 +1345,6 @@
       json.writeEndObject();
 
       json.close();
-      outputStream.close();
       return SerializerResultImpl.with().content(buffer.getInputStream()).build();
     } catch (final IOException e) {
       cachedException =
diff --git a/lib/server-core/src/test/java/org/apache/olingo/server/core/debug/AbstractDebugTabTest.java b/lib/server-core/src/test/java/org/apache/olingo/server/core/debug/AbstractDebugTabTest.java
index bbebe20..8ff5c26 100644
--- a/lib/server-core/src/test/java/org/apache/olingo/server/core/debug/AbstractDebugTabTest.java
+++ b/lib/server-core/src/test/java/org/apache/olingo/server/core/debug/AbstractDebugTabTest.java
@@ -40,10 +40,10 @@
       tab.appendHtml(writer);
     } else {
       // Create JSON generator (the object mapper is necessary to write expression trees).
-      JsonGenerator json = new ObjectMapper().getFactory().createGenerator(writer);
-      tab.appendJson(json);
-      json.flush();
-      json.close();
+      try (JsonGenerator json = new ObjectMapper().getFactory().createGenerator(writer)) {
+        tab.appendJson(json);
+        json.flush();
+      }
     }
     writer.flush();
     return writer.toString();