Polish diamond operator usage.

Closes #3620

Author: ngocnhan-tran1996

spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java

@@ -65,6 +65,7 @@
  * @author Donghun Shin
  * @author Greg Turnquist
  * @author Aref Behboodi
+ * @author Ngoc Nhan
  */
 @Transactional(readOnly = true)
 public class EnversRevisionRepositoryImpl<T, ID, N extends Number & Comparable<N>>
@@ -117,7 +118,7 @@ public Optional<Revision<N, T>> findRevision(ID id, N revisionNumber) {
 		Assert.notNull(id, "Identifier must not be null!");
 		Assert.notNull(revisionNumber, "Revision number must not be null!");
 
-		List<Object[]> singleResult = (List<Object[]>) createBaseQuery(id) //
+		List<Object[]> singleResult = createBaseQuery(id) //
 				.add(AuditEntity.revisionNumber().eq(revisionNumber)) //
 				.getResultList();
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/AbstractPersistable.java

@@ -34,6 +34,7 @@
  * @author Thomas Darimont
  * @author Mark Paluch
  * @author Greg Turnquist
+ * @author Ngoc Nhan
  * @param <PK> the type of the identifier.
  */
 @MappedSuperclass
@@ -89,7 +90,7 @@ public boolean equals(Object obj) {
 
 		AbstractPersistable<?> that = (AbstractPersistable<?>) obj;
 
-		return null == this.getId() ? false : this.getId().equals(that.getId());
+		return this.getId() != null && this.getId().equals(that.getId());
 	}
 
 	@Override

spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java

@@ -37,6 +37,7 @@
  * @author Christoph Strobl
  * @author David Madden
  * @author Jens Schauder
+ * @author Ngoc Nhan
  */
 public class JpaSort extends Sort {
 
@@ -281,14 +282,14 @@ public <A extends Attribute<S, U>, U> Path<S, U> dot(A attribute) {
 		 * @return
 		 */
 		public <P extends PluralAttribute<S, ?, U>, U> Path<S, U> dot(P attribute) {
-			return new Path<S, U>(add(attribute));
+			return new Path<>(add(attribute));
 		}
 
 		private List<Attribute<?, ?>> add(Attribute<?, ?> attribute) {
 
 			Assert.notNull(attribute, "Attribute must not be null");
 
-			List<Attribute<?, ?>> newAttributes = new ArrayList<Attribute<?, ?>>(attributes.size() + 1);
+			List<Attribute<?, ?>> newAttributes = new ArrayList<>(attributes.size() + 1);
 			newAttributes.addAll(attributes);
 			newAttributes.add(attribute);
 			return newAttributes;