[MVERIFIER-36] Code cleanup, move to Java 7

Closes #1
diff --git a/src/main/java/org/apache/maven/plugins/verifier/ConsoleVerificationResultPrinter.java b/src/main/java/org/apache/maven/plugins/verifier/ConsoleVerificationResultPrinter.java
index 64f33a4..90d20b5 100644
--- a/src/main/java/org/apache/maven/plugins/verifier/ConsoleVerificationResultPrinter.java
+++ b/src/main/java/org/apache/maven/plugins/verifier/ConsoleVerificationResultPrinter.java
@@ -20,6 +20,7 @@
  */
 
 import org.apache.maven.plugin.logging.Log;
+import org.apache.maven.plugins.verifier.model.File;
 
 /**
  * 
@@ -42,37 +43,18 @@
      */
     public void print( VerificationResult results )
     {
-        printExistenceFailures( results );
-        printNonExistenceFailures( results );
-        printContentFailures( results );
-    }
-
-    private void printExistenceFailures( VerificationResult results )
-    {
-        for ( Object o : results.getExistenceFailures() )
+        for ( File file : results.getExistenceFailures() )
         {
-            org.apache.maven.plugins.verifier.model.File file = (org.apache.maven.plugins.verifier.model.File) o;
-
             printMessage( "File not found [" + file.getLocation() + "]" );
         }
-    }
 
-    private void printNonExistenceFailures( VerificationResult results )
-    {
-        for ( Object o : results.getNonExistenceFailures() )
+        for ( File file : results.getNonExistenceFailures() )
         {
-            org.apache.maven.plugins.verifier.model.File file = (org.apache.maven.plugins.verifier.model.File) o;
-
             printMessage( "File should not exist [" + file.getLocation() + "]" );
         }
-    }
 
-    private void printContentFailures( VerificationResult results )
-    {
-        for ( Object o : results.getContentFailures() )
+        for ( File file : results.getContentFailures() )
         {
-            org.apache.maven.plugins.verifier.model.File file = (org.apache.maven.plugins.verifier.model.File) o;
-
             printMessage( "File [" + file.getLocation() + "] does not match regexp [" + file.getContains() + "]" );
         }
     }
diff --git a/src/main/java/org/apache/maven/plugins/verifier/VerificationResult.java b/src/main/java/org/apache/maven/plugins/verifier/VerificationResult.java
index c4c7a60..111468b 100644
--- a/src/main/java/org/apache/maven/plugins/verifier/VerificationResult.java
+++ b/src/main/java/org/apache/maven/plugins/verifier/VerificationResult.java
@@ -29,11 +29,11 @@
  */
 public class VerificationResult
 {
-    private List<File> existenceFailures = new ArrayList<File>();
+    private List<File> existenceFailures = new ArrayList<>();
 
-    private List<File> nonExistenceFailures = new ArrayList<File>();
+    private List<File> nonExistenceFailures = new ArrayList<>();
 
-    private List<File> contentFailures = new ArrayList<File>();
+    private List<File> contentFailures = new ArrayList<>();
 
     /**
      * @param file {@link File}
diff --git a/src/main/java/org/apache/maven/plugins/verifier/VerifierMojo.java b/src/main/java/org/apache/maven/plugins/verifier/VerifierMojo.java
index 5132efe..c093ec6 100644
--- a/src/main/java/org/apache/maven/plugins/verifier/VerifierMojo.java
+++ b/src/main/java/org/apache/maven/plugins/verifier/VerifierMojo.java
@@ -53,7 +53,7 @@
 import org.apache.maven.plugins.verifier.model.Verifications;
 import org.apache.maven.plugins.verifier.model.io.xpp3.VerificationsXpp3Reader;
 import org.codehaus.plexus.util.FileUtils;
-import org.codehaus.plexus.util.IOUtil;
+import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
 
 /**
  * Verifies the existence or non-existence of files/directories and optionally checks file content against a regular
@@ -74,10 +74,9 @@
     /**
      * The file containing the verifications to perform.
      */
-    // CHECKSTYLE_OFF: LineLength
-    @Parameter( property = "verifier.verificationFile", defaultValue = "${basedir}/src/test/verifier/verifications.xml", required = true )
+    @Parameter( property = "verifier.verificationFile", defaultValue = "${basedir}/src/test/verifier/verifications.xml",
+            required = true )
     private File verificationFile;
-    // CHECKSTYLE_ON: LineLength
 
     /**
      * Whether the build will fail on verification errors.
@@ -94,7 +93,7 @@
         throws MojoExecutionException
     {
         VerificationResult results = verify();
-        this.resultPrinter.print( results );
+        resultPrinter.print( results );
 
         // Fail the build if there are errors
         if ( this.failOnError && results.hasFailures() )
@@ -123,17 +122,11 @@
     {
         VerificationResult results = new VerificationResult();
 
-        Reader reader = null;
-        try
+        try ( Reader reader = new FileReader( verificationFile ) )
         {
-            reader = new FileReader( this.verificationFile );
-
             VerificationsXpp3Reader xppReader = new VerificationsXpp3Reader();
             Verifications verifications = xppReader.read( reader );
 
-            reader.close();
-            reader = null;
-
             for ( org.apache.maven.plugins.verifier.model.File file : verifications.getFiles() )
             {
                 // Transform the file to check into an absolute path prefixing the basedir if
@@ -149,18 +142,10 @@
                 }
             }
         }
-        catch ( org.codehaus.plexus.util.xml.pull.XmlPullParserException e )
+        catch ( XmlPullParserException | IOException e )
         {
             throw new MojoExecutionException( "Error while verifying files", e );
         }
-        catch ( IOException e )
-        {
-            throw new MojoExecutionException( "Error while verifying files", e );
-        }
-        finally
-        {
-            IOUtil.close( reader );
-        }
 
         return results;
     }
@@ -179,8 +164,8 @@
         return result;
     }
 
-    // CHECKSTYLE_OFF: LineLength
-    private boolean verifyFileContent( org.apache.maven.plugins.verifier.model.File fileCheck, VerificationResult results )
+    private boolean verifyFileContent( org.apache.maven.plugins.verifier.model.File fileCheck,
+            VerificationResult results )
         throws IOException
     {
         boolean result = false;
@@ -204,7 +189,6 @@
 
         return result;
     }
-    // CHECKSTYLE_ON: LineLength
 
     private boolean verifyFileExistence( org.apache.maven.plugins.verifier.model.File fileCheck,
                                          VerificationResult results )
diff --git a/src/test/java/org/apache/maven/plugins/verifier/VerifierMojoTest.java b/src/test/java/org/apache/maven/plugins/verifier/VerifierMojoTest.java
index d6afbdc..0129ee3 100644
--- a/src/test/java/org/apache/maven/plugins/verifier/VerifierMojoTest.java
+++ b/src/test/java/org/apache/maven/plugins/verifier/VerifierMojoTest.java
@@ -1,14 +1,5 @@
 package org.apache.maven.plugins.verifier;
 
-import java.io.File;
-import java.io.UnsupportedEncodingException;
-import java.net.URLDecoder;
-
-import org.apache.maven.plugin.MojoExecutionException;
-import org.apache.maven.plugins.verifier.VerificationResult;
-import org.apache.maven.plugins.verifier.VerificationResultPrinter;
-import org.apache.maven.plugins.verifier.VerifierMojo;
-
 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
@@ -28,18 +19,26 @@
  * under the License.
  */
 
-import junit.framework.TestCase;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.UnsupportedEncodingException;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.*;
 
 public class VerifierMojoTest
-    extends TestCase
 {
     private File getResourceFile( String name ) throws UnsupportedEncodingException
     {
         String file = getClass().getResource( name ).getFile();
-        String decode = URLDecoder.decode( file, "UTF-8" ); // necessary for JDK 1.5+, where spaces are escaped to %20
+        String decode = URLDecoder.decode( file, StandardCharsets.UTF_8.toString()  ); // necessary for JDK 1.5+, where spaces are escaped to %20
         return new File( decode );
     }
 
+    @Test
     public void testPrefixWithBaseDir()
     {
         VerifierMojo mojo = new VerifierMojo();
@@ -51,6 +50,7 @@
         assertEquals( expectedResult.getPath(), result.getPath() );
     }
 
+    @Test
     public void testDoNotPrefixWhenAbsolutePath()
     {
         VerifierMojo mojo = new VerifierMojo();
@@ -62,6 +62,7 @@
         assertEquals( absoluteFile.getPath(), result.getPath() );
     }
 
+    @Test
     public void testCheckFileThatDoesNotExist()
         throws Exception
     {
@@ -91,6 +92,7 @@
         }
     }
 
+    @Test
     public void testCheckFileThatExists()
         throws Exception
     {
@@ -112,6 +114,7 @@
         mojo.execute();
     }
 
+    @Test
     public void testCheckForInexistentFile()
         throws Exception
     {
@@ -132,6 +135,7 @@
         mojo.execute();
     }
 
+    @Test
     public void testCheckForInexistentFileThatExists()
         throws Exception
     {
@@ -161,6 +165,7 @@
         }
     }
 
+    @Test
     public void testCheckFileForContent()
         throws Exception
     {
@@ -181,6 +186,7 @@
         mojo.execute();
     }
 
+    @Test
     public void testCheckFileForInvalidContent()
         throws Exception
     {