diff --git a/spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java b/spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java
index 71e5c48cc..c86573d16 100755
--- a/spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java
+++ b/spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java
@@ -65,6 +65,7 @@ import org.springframework.util.Assert;
  * @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 class EnversRevisionRepositoryImpl<T, ID, N extends Number & Comparable<N
 		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();
 
diff --git a/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/AbstractPersistable.java b/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/AbstractPersistable.java
index 245418357..989eac2cf 100644
--- a/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/AbstractPersistable.java
+++ b/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/AbstractPersistable.java
@@ -34,6 +34,7 @@ import org.springframework.lang.Nullable;
  * @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 abstract class AbstractPersistable<PK extends Serializable> implements Pe
 
 		AbstractPersistable<?> that = (AbstractPersistable<?>) obj;
 
-		return null == this.getId() ? false : this.getId().equals(that.getId());
+		return this.getId() != null && this.getId().equals(that.getId());
 	}
 
 	@Override
diff --git a/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java b/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java
index f93056417..771b5361a 100644
--- a/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java
+++ b/spring-data-jpa/src/main/java/org/springframework/data/jpa/domain/JpaSort.java
@@ -37,6 +37,7 @@ import java.util.List;
  * @author Christoph Strobl
  * @author David Madden
  * @author Jens Schauder
+ * @author Ngoc Nhan
  */
 public class JpaSort extends Sort {
 
@@ -281,14 +282,14 @@ public class JpaSort extends Sort {
 		 * @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;