diff --git a/spring-aop/src/main/java/org/springframework/aop/aspectj/MethodInvocationProceedingJoinPoint.java b/spring-aop/src/main/java/org/springframework/aop/aspectj/MethodInvocationProceedingJoinPoint.java
index df83c3d72c..b564a4f999 100644
--- a/spring-aop/src/main/java/org/springframework/aop/aspectj/MethodInvocationProceedingJoinPoint.java
+++ b/spring-aop/src/main/java/org/springframework/aop/aspectj/MethodInvocationProceedingJoinPoint.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -212,10 +212,12 @@ public class MethodInvocationProceedingJoinPoint implements ProceedingJoinPoint,
 
 		@Override
 		public String[] getParameterNames() {
-			if (this.parameterNames == null) {
-				this.parameterNames = parameterNameDiscoverer.getParameterNames(getMethod());
+			String[] parameterNames = this.parameterNames;
+			if (parameterNames == null) {
+				parameterNames = parameterNameDiscoverer.getParameterNames(getMethod());
+				this.parameterNames = parameterNames;
 			}
-			return this.parameterNames;
+			return parameterNames;
 		}
 
 		@Override
diff --git a/spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java b/spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java
index 52c7bec89b..35ce17dee8 100644
--- a/spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java
+++ b/spring-beans/src/main/java/org/springframework/beans/BeanWrapperImpl.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -69,7 +69,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	private CachedIntrospectionResults cachedIntrospectionResults;
 
 	/**
-	 * The security context used for invoking the property methods
+	 * The security context used for invoking the property methods.
 	 */
 	private AccessControlContext acc;
 
@@ -95,7 +95,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 
 	/**
 	 * Create a new BeanWrapperImpl for the given object.
-	 * @param object object wrapped by this BeanWrapper
+	 * @param object the object wrapped by this BeanWrapper
 	 */
 	public BeanWrapperImpl(Object object) {
 		super(object);
@@ -112,7 +112,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	/**
 	 * Create a new BeanWrapperImpl for the given object,
 	 * registering a nested path that the object is in.
-	 * @param object object wrapped by this BeanWrapper
+	 * @param object the object wrapped by this BeanWrapper
 	 * @param nestedPath the nested path of the object
 	 * @param rootObject the root object at the top of the path
 	 */
@@ -123,7 +123,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	/**
 	 * Create a new BeanWrapperImpl for the given object,
 	 * registering a nested path that the object is in.
-	 * @param object object wrapped by this BeanWrapper
+	 * @param object the object wrapped by this BeanWrapper
 	 * @param nestedPath the nested path of the object
 	 * @param parent the containing BeanWrapper (must not be {@code null})
 	 */
@@ -164,7 +164,7 @@ public class BeanWrapperImpl extends AbstractNestablePropertyAccessor implements
 	}
 
 	/**
-	 * Obtain a lazily initializted CachedIntrospectionResults instance
+	 * Obtain a lazily initialized CachedIntrospectionResults instance
 	 * for the wrapped object.
 	 */
 	private CachedIntrospectionResults getCachedIntrospectionResults() {
diff --git a/spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java b/spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java
index cc8a520e10..3a4c7a5ba5 100644
--- a/spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java
+++ b/spring-beans/src/main/java/org/springframework/beans/DirectFieldAccessor.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,7 +51,7 @@ public class DirectFieldAccessor extends AbstractNestablePropertyAccessor {
 
 	/**
 	 * Create a new DirectFieldAccessor for the given object.
-	 * @param object object wrapped by this DirectFieldAccessor
+	 * @param object the object wrapped by this DirectFieldAccessor
 	 */
 	public DirectFieldAccessor(Object object) {
 		super(object);
@@ -60,7 +60,7 @@ public class DirectFieldAccessor extends AbstractNestablePropertyAccessor {
 	/**
 	 * Create a new DirectFieldAccessor for the given object,
 	 * registering a nested path that the object is in.
-	 * @param object object wrapped by this DirectFieldAccessor
+	 * @param object the object wrapped by this DirectFieldAccessor
 	 * @param nestedPath the nested path of the object
 	 * @param parent the containing DirectFieldAccessor (must not be {@code null})
 	 */
@@ -90,8 +90,7 @@ public class DirectFieldAccessor extends AbstractNestablePropertyAccessor {
 	@Override
 	protected NotWritablePropertyException createNotWritablePropertyException(String propertyName) {
 		PropertyMatches matches = PropertyMatches.forField(propertyName, getRootClass());
-		throw new NotWritablePropertyException(
-				getRootClass(), getNestedPath() + propertyName,
+		throw new NotWritablePropertyException(getRootClass(), getNestedPath() + propertyName,
 				matches.buildErrorMessage(), matches.getPossibleMatches());
 	}