Apply "type inference for generic instance creation" Java 7 feature

Change-Id: Ia14802c903ca67b9d94dc6038d70b0e9644bc621

gerrit-server/src/main/java/com/google/gerrit/rules/PrologCompiler.java

@@ -154,13 +154,13 @@ public class PrologCompiler implements Callable<PrologCompiler.Status> {
     }
 
     DiagnosticCollector<JavaFileObject> diagnostics =
-        new DiagnosticCollector<JavaFileObject>();
+        new DiagnosticCollector<>();
     StandardJavaFileManager fileManager =
         compiler.getStandardFileManager(diagnostics, null, null);
     try {
       Iterable<? extends JavaFileObject> compilationUnits = fileManager
         .getJavaFileObjectsFromFiles(getAllFiles(tempDir, ".java"));
-      ArrayList<String> options = new ArrayList<String>();
+      ArrayList<String> options = new ArrayList<>();
       String classpath = getMyClasspath();
       if (classpath != null) {
         options.add("-classpath");
@@ -270,7 +270,7 @@ public class PrologCompiler implements Callable<PrologCompiler.Status> {
   }
 
   private List<File> getAllFiles(File dir, String extension) {
-    ArrayList<File> fileList = new ArrayList<File>();
+    ArrayList<File> fileList = new ArrayList<>();
     getAllFiles(dir, extension, fileList);
     return fileList;
   }
@@ -287,7 +287,7 @@ public class PrologCompiler implements Callable<PrologCompiler.Status> {
   }
 
   private List<String> getRelativePaths(File dir, String extension) {
-    ArrayList<String> pathList = new ArrayList<String>();
+    ArrayList<String> pathList = new ArrayList<>();
     getRelativePaths(dir, extension, "", pathList);
     return pathList;
   }

gerrit-server/src/main/java/com/google/gerrit/rules/PrologEnvironment.java

@@ -73,8 +73,8 @@ public class PrologEnvironment extends BufferingPrologControl {
     setMaxArity(MAX_ARITY);
     setEnabled(EnumSet.allOf(Prolog.Feature.class), false);
     args = a;
-    storedValues = new HashMap<StoredValue<Object>, Object>();
-    cleanup = new LinkedList<Runnable>();
+    storedValues = new HashMap<>();
+    cleanup = new LinkedList<>();
   }
 
   public Args getArgs() {

gerrit-server/src/main/java/com/google/gerrit/rules/RulesCache.java

@@ -80,11 +80,10 @@ public class RulesCache {
   private static final List<String> PACKAGE_LIST = ImmutableList.of(
       Prolog.BUILTIN, "gerrit");
 
-  private final Map<ObjectId, MachineRef> machineCache =
-      new HashMap<ObjectId, MachineRef>();
+  private final Map<ObjectId, MachineRef> machineCache = new HashMap<>();
 
   private final ReferenceQueue<PrologMachineCopy> dead =
-      new ReferenceQueue<PrologMachineCopy>();
+      new ReferenceQueue<>();
 
   private static final class MachineRef extends WeakReference<PrologMachineCopy> {
     final ObjectId key;

gerrit-server/src/main/java/com/google/gerrit/rules/StoredValue.java

@@ -25,12 +25,12 @@ import com.googlecode.prolog_cafe.lang.SystemException;
 public class StoredValue<T> {
   /** Construct a new unique key that does not match any other key. */
   public static <T> StoredValue<T> create() {
-    return new StoredValue<T>();
+    return new StoredValue<>();
   }
 
   /** Construct a key based on a Java Class object, useful for singletons. */
   public static <T> StoredValue<T> create(Class<T> clazz) {
-    return new StoredValue<T>(clazz);
+    return new StoredValue<>(clazz);
   }
 
   private final Object key;