Use consistent class design

Update all classes so that inner classes are always last. Also
ensure that utility classes are always final and have a private
constructor and make exceptions final whenever possible.

Issue: SPR-16968

spring-aop/src/main/java/org/springframework/aop/TrueClassFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -24,7 +24,7 @@ import java.io.Serializable;
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")
-class TrueClassFilter implements ClassFilter, Serializable {
+final class TrueClassFilter implements ClassFilter, Serializable {
 
 	public static final TrueClassFilter INSTANCE = new TrueClassFilter();
 

spring-aop/src/main/java/org/springframework/aop/TrueMethodMatcher.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -27,7 +27,7 @@ import org.springframework.lang.Nullable;
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")
-class TrueMethodMatcher implements MethodMatcher, Serializable {
+final class TrueMethodMatcher implements MethodMatcher, Serializable {
 
 	public static final TrueMethodMatcher INSTANCE = new TrueMethodMatcher();
 

spring-aop/src/main/java/org/springframework/aop/TruePointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -24,7 +24,7 @@ import java.io.Serializable;
  * @author Rod Johnson
  */
 @SuppressWarnings("serial")
-class TruePointcut implements Pointcut, Serializable {
+final class TruePointcut implements Pointcut, Serializable {
 
 	public static final TruePointcut INSTANCE = new TruePointcut();
 

spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java

@@ -561,6 +561,19 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 		return sb.toString();
 	}
 
+	//---------------------------------------------------------------------
+	// Serialization support
+	//---------------------------------------------------------------------
+
+	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
+		// Rely on default serialization, just initialize state after deserialization.
+		ois.defaultReadObject();
+
+		// Initialize transient fields.
+		// pointcutExpression will be initialized lazily by checkReadyToMatch()
+		this.shadowMatchCache = new ConcurrentHashMap<>(32);
+	}
+
 
 	/**
 	 * Handler for the Spring-specific {@code bean()} pointcut designator
@@ -657,20 +670,6 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 	}
 
 
-	//---------------------------------------------------------------------
-	// Serialization support
-	//---------------------------------------------------------------------
-
-	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
-		// Rely on default serialization, just initialize state after deserialization.
-		ois.defaultReadObject();
-
-		// Initialize transient fields.
-		// pointcutExpression will be initialized lazily by checkReadyToMatch()
-		this.shadowMatchCache = new ConcurrentHashMap<>(32);
-	}
-
-
 	private static class DefensiveShadowMatch implements ShadowMatch {
 
 		private final ShadowMatch primary;

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/InstantiationModelAwarePointcutAdvisorImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -42,7 +42,7 @@ import org.springframework.lang.Nullable;
  * @since 2.0
  */
 @SuppressWarnings("serial")
-class InstantiationModelAwarePointcutAdvisorImpl
+final class InstantiationModelAwarePointcutAdvisorImpl
 		implements InstantiationModelAwarePointcutAdvisor, AspectJPrecedenceInformation, Serializable {
 
 	private static final Advice EMPTY_ADVICE = new Advice() {};
@@ -264,7 +264,7 @@ class InstantiationModelAwarePointcutAdvisorImpl
 	 * Note that this is a <i>dynamic</i> pointcut. Otherwise it might
 	 * be optimized out if it does not at first match statically.
 	 */
-	private class PerTargetInstantiationModelPointcut extends DynamicMethodMatcherPointcut {
+	private final class PerTargetInstantiationModelPointcut extends DynamicMethodMatcherPointcut {
 
 		private final AspectJExpressionPointcut declaredPointcut;
 

spring-aop/src/main/java/org/springframework/aop/aspectj/annotation/NotAnAtAspectException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -29,7 +29,7 @@ import org.springframework.aop.framework.AopConfigException;
 @SuppressWarnings("serial")
 public class NotAnAtAspectException extends AopConfigException {
 
-	private Class<?> nonAspectClass;
+	private final Class<?> nonAspectClass;
 
 
 	/**

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/ProxyCreationContext.java

@@ -27,13 +27,17 @@ import org.springframework.lang.Nullable;
  * @author Ramnivas Laddad
  * @since 2.5
  */
-public class ProxyCreationContext {
+public final class ProxyCreationContext {
 
 	/** ThreadLocal holding the current proxied bean name during Advisor matching. */
 	private static final ThreadLocal<String> currentProxiedBeanName =
 			new NamedThreadLocal<>("Name of currently proxied bean");
 
 
+	private ProxyCreationContext() {
+	}
+
+
 	/**
 	 * Return the name of the currently proxied bean instance.
 	 * @return the name of the bean, or {@code null} if none available

spring-aop/src/main/java/org/springframework/aop/interceptor/ExposeInvocationInterceptor.java

@@ -41,7 +41,7 @@ import org.springframework.core.PriorityOrdered;
  * @author Juergen Hoeller
  */
 @SuppressWarnings("serial")
-public class ExposeInvocationInterceptor implements MethodInterceptor, PriorityOrdered, Serializable {
+public final class ExposeInvocationInterceptor implements MethodInterceptor, PriorityOrdered, Serializable {
 
 	/** Singleton instance of this class. */
 	public static final ExposeInvocationInterceptor INSTANCE = new ExposeInvocationInterceptor();

spring-aop/src/main/java/org/springframework/aop/target/EmptyTargetSource.java

@@ -30,7 +30,7 @@ import org.springframework.util.ObjectUtils;
  * @author Rod Johnson
  * @author Juergen Hoeller
  */
-public class EmptyTargetSource implements TargetSource, Serializable {
+public final class EmptyTargetSource implements TargetSource, Serializable {
 
 	/** use serialVersionUID from Spring 1.2 for interoperability. */
 	private static final long serialVersionUID = 3680494563553489691L;

spring-aspects/src/main/java/org/springframework/cache/aspectj/AnyThrow.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -22,7 +22,11 @@ package org.springframework.cache.aspectj;
  *
  * @author Stephane Nicoll
  */
-class AnyThrow {
+final class AnyThrow {
+
+	private AnyThrow() {
+	}
+
 
 	static void throwUnchecked(Throwable e) {
 		AnyThrow.<RuntimeException>throwAny(e);

spring-beans/src/main/java/org/springframework/beans/BeanInstantiationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,13 +31,13 @@ import org.springframework.lang.Nullable;
 @SuppressWarnings("serial")
 public class BeanInstantiationException extends FatalBeanException {
 
-	private Class<?> beanClass;
+	private final Class<?> beanClass;
 
 	@Nullable
-	private Constructor<?> constructor;
+	private final Constructor<?> constructor;
 
 	@Nullable
-	private Method constructingMethod;
+	private final Method constructingMethod;
 
 
 	/**
@@ -58,6 +58,8 @@ public class BeanInstantiationException extends FatalBeanException {
 	public BeanInstantiationException(Class<?> beanClass, String msg, @Nullable Throwable cause) {
 		super("Failed to instantiate [" + beanClass.getName() + "]: " + msg, cause);
 		this.beanClass = beanClass;
+		this.constructor = null;
+		this.constructingMethod = null;
 	}
 
 	/**
@@ -71,6 +73,7 @@ public class BeanInstantiationException extends FatalBeanException {
 		super("Failed to instantiate [" + constructor.getDeclaringClass().getName() + "]: " + msg, cause);
 		this.beanClass = constructor.getDeclaringClass();
 		this.constructor = constructor;
+		this.constructingMethod = null;
 	}
 
 	/**
@@ -84,6 +87,7 @@ public class BeanInstantiationException extends FatalBeanException {
 	public BeanInstantiationException(Method constructingMethod, String msg, @Nullable Throwable cause) {
 		super("Failed to instantiate [" + constructingMethod.getReturnType().getName() + "]: " + msg, cause);
 		this.beanClass = constructingMethod.getReturnType();
+		this.constructor = null;
 		this.constructingMethod = constructingMethod;
 	}
 

spring-beans/src/main/java/org/springframework/beans/CachedIntrospectionResults.java

@@ -71,7 +71,7 @@ import org.springframework.util.StringUtils;
  * @see #clearClassLoader(ClassLoader)
  * @see #forClass(Class)
  */
-public class CachedIntrospectionResults {
+public final class CachedIntrospectionResults {
 
 	/**
 	 * System property that instructs Spring to use the {@link Introspector#IGNORE_ALL_BEANINFO}

spring-beans/src/main/java/org/springframework/beans/InvalidPropertyException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,9 +28,9 @@ import org.springframework.lang.Nullable;
 @SuppressWarnings("serial")
 public class InvalidPropertyException extends FatalBeanException {
 
-	private Class<?> beanClass;
+	private final Class<?> beanClass;
 
-	private String propertyName;
+	private final String propertyName;
 
 
 	/**

spring-beans/src/main/java/org/springframework/beans/NotWritablePropertyException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,7 +30,7 @@ import org.springframework.lang.Nullable;
 public class NotWritablePropertyException extends InvalidPropertyException {
 
 	@Nullable
-	private String[] possibleMatches;
+	private final String[] possibleMatches;
 
 
 	/**
@@ -42,6 +42,7 @@ public class NotWritablePropertyException extends InvalidPropertyException {
 		super(beanClass, propertyName,
 				"Bean property '" + propertyName + "' is not writable or has an invalid setter method: " +
 				"Does the return type of the getter match the parameter type of the setter?");
+		this.possibleMatches = null;
 	}
 
 	/**
@@ -52,6 +53,7 @@ public class NotWritablePropertyException extends InvalidPropertyException {
 	 */
 	public NotWritablePropertyException(Class<?> beanClass, String propertyName, String msg) {
 		super(beanClass, propertyName, msg);
+		this.possibleMatches = null;
 	}
 
 	/**
@@ -63,6 +65,7 @@ public class NotWritablePropertyException extends InvalidPropertyException {
 	 */
 	public NotWritablePropertyException(Class<?> beanClass, String propertyName, String msg, Throwable cause) {
 		super(beanClass, propertyName, msg, cause);
+		this.possibleMatches = null;
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/PropertyAccessException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,7 +31,7 @@ import org.springframework.lang.Nullable;
 public abstract class PropertyAccessException extends BeansException {
 
 	@Nullable
-	private transient PropertyChangeEvent propertyChangeEvent;
+	private final PropertyChangeEvent propertyChangeEvent;
 
 
 	/**
@@ -52,6 +52,7 @@ public abstract class PropertyAccessException extends BeansException {
 	 */
 	public PropertyAccessException(String msg, @Nullable Throwable cause) {
 		super(msg, cause);
+		this.propertyChangeEvent = null;
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/PropertyBatchUpdateException.java

@@ -40,7 +40,7 @@ import org.springframework.util.ObjectUtils;
 public class PropertyBatchUpdateException extends BeansException {
 
 	/** List of PropertyAccessException objects. */
-	private PropertyAccessException[] propertyAccessExceptions;
+	private final PropertyAccessException[] propertyAccessExceptions;
 
 
 	/**

spring-beans/src/main/java/org/springframework/beans/PropertyDescriptorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,7 +30,12 @@ import org.springframework.util.ObjectUtils;
  * @author Chris Beams
  * @author Juergen Hoeller
  */
-class PropertyDescriptorUtils {
+final class PropertyDescriptorUtils {
+
+
+	private PropertyDescriptorUtils() {
+	}
+
 
 	/**
 	 * See {@link java.beans.FeatureDescriptor}.

spring-beans/src/main/java/org/springframework/beans/PropertyEditorRegistrySupport.java

@@ -517,7 +517,7 @@ public class PropertyEditorRegistrySupport implements PropertyEditorRegistry {
 	 * Holder for a registered custom editor with property name.
 	 * Keeps the PropertyEditor itself plus the type it was registered for.
 	 */
-	private static class CustomEditorHolder {
+	private static final class CustomEditorHolder {
 
 		private final PropertyEditor propertyEditor;
 

spring-beans/src/main/java/org/springframework/beans/factory/BeanCreationException.java

@@ -35,10 +35,10 @@ import org.springframework.lang.Nullable;
 public class BeanCreationException extends FatalBeanException {
 
 	@Nullable
-	private String beanName;
+	private final String beanName;
 
 	@Nullable
-	private String resourceDescription;
+	private final String resourceDescription;
 
 	@Nullable
 	private List<Throwable> relatedCauses;
@@ -50,6 +50,8 @@ public class BeanCreationException extends FatalBeanException {
 	 */
 	public BeanCreationException(String msg) {
 		super(msg);
+		this.beanName = null;
+		this.resourceDescription = null;
 	}
 
 	/**
@@ -59,6 +61,8 @@ public class BeanCreationException extends FatalBeanException {
 	 */
 	public BeanCreationException(String msg, Throwable cause) {
 		super(msg, cause);
+		this.beanName = null;
+		this.resourceDescription = null;
 	}
 
 	/**
@@ -69,6 +73,7 @@ public class BeanCreationException extends FatalBeanException {
 	public BeanCreationException(String beanName, String msg) {
 		super("Error creating bean with name '" + beanName + "': " + msg);
 		this.beanName = beanName;
+		this.resourceDescription = null;
 	}
 
 	/**
@@ -94,6 +99,7 @@ public class BeanCreationException extends FatalBeanException {
 				(resourceDescription != null ? " defined in " + resourceDescription : "") + ": " + msg);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;
+		this.relatedCauses = null;
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/BeanDefinitionStoreException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,10 +31,10 @@ import org.springframework.lang.Nullable;
 public class BeanDefinitionStoreException extends FatalBeanException {
 
 	@Nullable
-	private String resourceDescription;
+	private final String resourceDescription;
 
 	@Nullable
-	private String beanName;
+	private final String beanName;
 
 
 	/**
@@ -43,6 +43,8 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 */
 	public BeanDefinitionStoreException(String msg) {
 		super(msg);
+		this.resourceDescription = null;
+		this.beanName = null;
 	}
 
 	/**
@@ -52,6 +54,8 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	 */
 	public BeanDefinitionStoreException(String msg, @Nullable Throwable cause) {
 		super(msg, cause);
+		this.resourceDescription = null;
+		this.beanName = null;
 	}
 
 	/**
@@ -62,6 +66,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	public BeanDefinitionStoreException(@Nullable String resourceDescription, String msg) {
 		super(msg);
 		this.resourceDescription = resourceDescription;
+		this.beanName = null;
 	}
 
 	/**
@@ -73,6 +78,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	public BeanDefinitionStoreException(@Nullable String resourceDescription, String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 		this.resourceDescription = resourceDescription;
+		this.beanName = null;
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/BeanNotOfRequiredTypeException.java

@@ -29,13 +29,13 @@ import org.springframework.util.ClassUtils;
 public class BeanNotOfRequiredTypeException extends BeansException {
 
 	/** The name of the instance that was of the wrong type. */
-	private String beanName;
+	private final String beanName;
 
 	/** The required type. */
-	private Class<?> requiredType;
+	private final Class<?> requiredType;
 
 	/** The offending type. */
-	private Class<?> actualType;
+	private final Class<?> actualType;
 
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/CannotLoadBeanClassException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,13 +30,13 @@ import org.springframework.lang.Nullable;
 public class CannotLoadBeanClassException extends FatalBeanException {
 
 	@Nullable
-	private String resourceDescription;
+	private final String resourceDescription;
 
 	@Nullable
-	private String beanName;
+	private final String beanName;
 
 	@Nullable
-	private String beanClassName;
+	private final String beanClassName;
 
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/NoSuchBeanDefinitionException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -36,10 +36,10 @@ import org.springframework.lang.Nullable;
 public class NoSuchBeanDefinitionException extends BeansException {
 
 	@Nullable
-	private String beanName;
+	private final String beanName;
 
 	@Nullable
-	private ResolvableType resolvableType;
+	private final ResolvableType resolvableType;
 
 
 	/**
@@ -49,6 +49,7 @@ public class NoSuchBeanDefinitionException extends BeansException {
 	public NoSuchBeanDefinitionException(String name) {
 		super("No bean named '" + name + "' available");
 		this.beanName = name;
+		this.resolvableType = null;
 	}
 
 	/**
@@ -59,6 +60,7 @@ public class NoSuchBeanDefinitionException extends BeansException {
 	public NoSuchBeanDefinitionException(String name, String message) {
 		super("No bean named '" + name + "' available: " + message);
 		this.beanName = name;
+		this.resolvableType = null;
 	}
 
 	/**
@@ -85,6 +87,7 @@ public class NoSuchBeanDefinitionException extends BeansException {
 	 */
 	public NoSuchBeanDefinitionException(ResolvableType type) {
 		super("No qualifying bean of type '" + type + "' available");
+		this.beanName = null;
 		this.resolvableType = type;
 	}
 
@@ -96,6 +99,7 @@ public class NoSuchBeanDefinitionException extends BeansException {
 	 */
 	public NoSuchBeanDefinitionException(ResolvableType type, String message) {
 		super("No qualifying bean of type '" + type + "' available: " + message);
+		this.beanName = null;
 		this.resolvableType = type;
 	}
 

spring-beans/src/main/java/org/springframework/beans/factory/NoUniqueBeanDefinitionException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -33,10 +33,10 @@ import org.springframework.util.StringUtils;
 @SuppressWarnings("serial")
 public class NoUniqueBeanDefinitionException extends NoSuchBeanDefinitionException {
 
-	private int numberOfBeansFound;
+	private final int numberOfBeansFound;
 
 	@Nullable
-	private Collection<String> beanNamesFound;
+	private final Collection<String> beanNamesFound;
 
 
 	/**
@@ -48,6 +48,7 @@ public class NoUniqueBeanDefinitionException extends NoSuchBeanDefinitionExcepti
 	public NoUniqueBeanDefinitionException(Class<?> type, int numberOfBeansFound, String message) {
 		super(type, message);
 		this.numberOfBeansFound = numberOfBeansFound;
+		this.beanNamesFound = null;
 	}
 
 	/**
@@ -56,8 +57,9 @@ public class NoUniqueBeanDefinitionException extends NoSuchBeanDefinitionExcepti
 	 * @param beanNamesFound the names of all matching beans (as a Collection)
 	 */
 	public NoUniqueBeanDefinitionException(Class<?> type, Collection<String> beanNamesFound) {
-		this(type, beanNamesFound.size(), "expected single matching bean but found " + beanNamesFound.size() + ": " +
+		super(type, "expected single matching bean but found " + beanNamesFound.size() + ": " +
 				StringUtils.collectionToCommaDelimitedString(beanNamesFound));
+		this.numberOfBeansFound =  beanNamesFound.size();
 		this.beanNamesFound = beanNamesFound;
 	}
 

spring-beans/src/main/java/org/springframework/beans/factory/UnsatisfiedDependencyException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -33,7 +33,7 @@ import org.springframework.util.StringUtils;
 public class UnsatisfiedDependencyException extends BeanCreationException {
 
 	@Nullable
-	private InjectionPoint injectionPoint;
+	private final InjectionPoint injectionPoint;
 
 
 	/**
@@ -49,6 +49,7 @@ public class UnsatisfiedDependencyException extends BeanCreationException {
 		super(resourceDescription, beanName,
 				"Unsatisfied dependency expressed through bean property '" + propertyName + "'" +
 				(StringUtils.hasLength(msg) ? ": " + msg : ""));
+		this.injectionPoint = null;
 	}
 
 	/**

spring-beans/src/main/java/org/springframework/beans/factory/config/PropertyPlaceholderConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -250,7 +250,7 @@ public class PropertyPlaceholderConfigurer extends PlaceholderConfigurerSupport
 	}
 
 
-	private class PropertyPlaceholderConfigurerResolver implements PlaceholderResolver {
+	private final class PropertyPlaceholderConfigurerResolver implements PlaceholderResolver {
 
 		private final Properties props;
 

spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -34,7 +34,7 @@ import org.springframework.util.ObjectUtils;
  * @author Juergen Hoeller
  * @since 2.0
  */
-public class BeanDefinitionBuilder {
+public final class BeanDefinitionBuilder {
 
 	/**
 	 * Create a new {@code BeanDefinitionBuilder} used to construct a {@link GenericBeanDefinition}.

spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionReaderUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -35,7 +35,7 @@ import org.springframework.util.StringUtils;
  * @see PropertiesBeanDefinitionReader
  * @see org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader
  */
-public class BeanDefinitionReaderUtils {
+public final class BeanDefinitionReaderUtils {
 
 	/**
 	 * Separator for generated bean names. If a class name or parent name is not
@@ -44,6 +44,10 @@ public class BeanDefinitionReaderUtils {
 	public static final String GENERATED_BEAN_NAME_SEPARATOR = BeanFactoryUtils.GENERATED_BEAN_NAME_SEPARATOR;
 
 
+	private BeanDefinitionReaderUtils() {
+	}
+
+
 	/**
 	 * Create a new GenericBeanDefinition for the given parent name and class name,
 	 * eagerly loading the bean class if a ClassLoader has been specified.

spring-context-support/src/main/java/org/springframework/mail/MailSendException.java

@@ -37,7 +37,7 @@ public class MailSendException extends MailException {
 	private final transient Map<Object, Exception> failedMessages;
 
 	@Nullable
-	private Exception[] messageExceptions;
+	private final Exception[] messageExceptions;
 
 
 	/**
@@ -56,6 +56,7 @@ public class MailSendException extends MailException {
 	public MailSendException(String msg, @Nullable Throwable cause) {
 		super(msg, cause);
 		this.failedMessages = new LinkedHashMap<>();
+		this.messageExceptions = null;
 	}
 
 	/**

spring-context/src/main/java/org/springframework/cache/config/CacheManagementConfigUtils.java

@@ -22,7 +22,7 @@ package org.springframework.cache.config;
  * @author Juergen Hoeller
  * @since 4.1
  */
-public class CacheManagementConfigUtils {
+public final class CacheManagementConfigUtils {
 
 	/**
 	 * The name of the cache advisor bean.
@@ -48,4 +48,8 @@ public class CacheManagementConfigUtils {
 	public static final String JCACHE_ASPECT_BEAN_NAME =
 			"org.springframework.cache.config.internalJCacheAspect";
 
+
+	private CacheManagementConfigUtils() {
+	}
+
 }

spring-context/src/main/java/org/springframework/context/annotation/AnnotationConfigUtils.java

@@ -60,7 +60,7 @@ import org.springframework.util.ClassUtils;
  * @see org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor
  * @see org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor
  */
-public class AnnotationConfigUtils {
+public final class AnnotationConfigUtils {
 
 	/**
 	 * The bean name of the internally managed Configuration annotation processor.
@@ -127,6 +127,10 @@ public class AnnotationConfigUtils {
 			ClassUtils.isPresent(PERSISTENCE_ANNOTATION_PROCESSOR_CLASS_NAME, AnnotationConfigUtils.class.getClassLoader());
 
 
+	private AnnotationConfigUtils() {
+	}
+
+
 	/**
 	 * Register all relevant annotation post processors in the given registry.
 	 * @param registry the registry to operate on

spring-context/src/main/java/org/springframework/context/annotation/BeanAnnotationHelper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -27,7 +27,12 @@ import org.springframework.core.annotation.AnnotatedElementUtils;
  * @author Juergen Hoeller
  * @since 3.1
  */
-class BeanAnnotationHelper {
+final class BeanAnnotationHelper {
+
+
+	private BeanAnnotationHelper() {
+	}
+
 
 	public static boolean isBeanAnnotated(Method method) {
 		return AnnotatedElementUtils.hasAnnotation(method, Bean.class);

spring-context/src/main/java/org/springframework/context/annotation/ScopedProxyCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,7 +28,12 @@ import org.springframework.beans.factory.support.BeanDefinitionRegistry;
  * @since 3.0
  * @see org.springframework.aop.scope.ScopedProxyUtils#createScopedProxy
  */
-class ScopedProxyCreator {
+final class ScopedProxyCreator {
+
+
+	private ScopedProxyCreator() {
+	}
+
 
 	public static BeanDefinitionHolder createScopedProxy(
 			BeanDefinitionHolder definitionHolder, BeanDefinitionRegistry registry, boolean proxyTargetClass) {

spring-context/src/main/java/org/springframework/context/index/CandidateComponentsIndexLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -39,7 +39,7 @@ import org.springframework.util.ConcurrentReferenceHashMap;
  * @author Stephane Nicoll
  * @since 5.0
  */
-public class CandidateComponentsIndexLoader {
+public final class CandidateComponentsIndexLoader {
 
 	/**
 	 * The location to look for components.
@@ -67,6 +67,10 @@ public class CandidateComponentsIndexLoader {
 			new ConcurrentReferenceHashMap<>();
 
 
+	private CandidateComponentsIndexLoader() {
+	}
+
+
 	/**
 	 * Load and instantiate the {@link CandidateComponentsIndex} from
 	 * {@value #COMPONENTS_RESOURCE_LOCATION}, using the given class loader. If no

spring-context/src/main/java/org/springframework/context/support/PostProcessorRegistrationDelegate.java

@@ -48,7 +48,12 @@ import org.springframework.lang.Nullable;
  * @author Juergen Hoeller
  * @since 4.0
  */
-class PostProcessorRegistrationDelegate {
+final class PostProcessorRegistrationDelegate {
+
+
+	private PostProcessorRegistrationDelegate() {
+	}
+
 
 	public static void invokeBeanFactoryPostProcessors(
 			ConfigurableListableBeanFactory beanFactory, List<BeanFactoryPostProcessor> beanFactoryPostProcessors) {

spring-context/src/main/java/org/springframework/format/datetime/joda/JodaTimeContextHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -38,6 +38,10 @@ public final class JodaTimeContextHolder {
 			new NamedThreadLocal<>("JodaTimeContext");
 
 
+	private JodaTimeContextHolder() {
+	}
+
+
 	/**
 	 * Reset the JodaTimeContext for the current thread.
 	 */

spring-context/src/main/java/org/springframework/format/datetime/joda/JodaTimeConverters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -46,6 +46,11 @@ import org.springframework.format.datetime.DateFormatterRegistrar;
  */
 final class JodaTimeConverters {
 
+
+	private JodaTimeConverters() {
+	}
+
+
 	/**
 	 * Install the converters into the converter registry.
 	 * @param registry the converter registry

spring-context/src/main/java/org/springframework/format/datetime/standard/DateTimeContextHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -35,6 +35,10 @@ public final class DateTimeContextHolder {
 			new NamedThreadLocal<>("DateTimeContext");
 
 
+	private DateTimeContextHolder() {
+	}
+
+
 	/**
 	 * Reset the DateTimeContext for the current thread.
 	 */

spring-context/src/main/java/org/springframework/format/datetime/standard/DateTimeConverters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -43,6 +43,11 @@ import org.springframework.format.datetime.DateFormatterRegistrar;
  */
 final class DateTimeConverters {
 
+
+	private DateTimeConverters() {
+	}
+
+
 	/**
 	 * Install the converters into the converter registry.
 	 * @param registry the converter registry

spring-context/src/main/java/org/springframework/jmx/support/ObjectNameManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,7 +28,12 @@ import javax.management.ObjectName;
  * @since 1.2
  * @see javax.management.ObjectName#getInstance(String)
  */
-public class ObjectNameManager {
+public final class ObjectNameManager {
+
+
+	private ObjectNameManager() {
+	}
+
 
 	/**
 	 * Retrieve the {@code ObjectName} instance corresponding to the supplied name.

spring-context/src/main/java/org/springframework/scheduling/config/TaskManagementConfigUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -22,7 +22,7 @@ package org.springframework.scheduling.config;
  * @author Juergen Hoeller
  * @since 4.1
  */
-public class TaskManagementConfigUtils {
+public final class TaskManagementConfigUtils {
 
 	/**
 	 * The bean name of the internally managed Scheduled annotation processor.
@@ -42,4 +42,9 @@ public class TaskManagementConfigUtils {
 	public static final String ASYNC_EXECUTION_ASPECT_BEAN_NAME =
 			"org.springframework.scheduling.config.internalAsyncExecutionAspect";
 
+
+	private TaskManagementConfigUtils() {
+	}
+
+
 }

spring-context/src/main/java/org/springframework/scripting/ScriptCompilationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -29,7 +29,7 @@ import org.springframework.lang.Nullable;
 public class ScriptCompilationException extends NestedRuntimeException {
 
 	@Nullable
-	private ScriptSource scriptSource;
+	private final ScriptSource scriptSource;
 
 
 	/**
@@ -38,6 +38,7 @@ public class ScriptCompilationException extends NestedRuntimeException {
 	 */
 	public ScriptCompilationException(String msg) {
 		super(msg);
+		this.scriptSource = null;
 	}
 
 	/**
@@ -47,6 +48,7 @@ public class ScriptCompilationException extends NestedRuntimeException {
 	 */
 	public ScriptCompilationException(String msg, Throwable cause) {
 		super(msg, cause);
+		this.scriptSource = null;
 	}
 
 	/**

spring-context/src/main/java/org/springframework/scripting/bsh/BshScriptUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -225,7 +225,7 @@ public abstract class BshScriptUtils {
 	 * Exception to be thrown on script execution failure.
 	 */
 	@SuppressWarnings("serial")
-	public static class BshExecutionException extends NestedRuntimeException {
+	public static final class BshExecutionException extends NestedRuntimeException {
 
 		private BshExecutionException(EvalError ex) {
 			super("BeanShell script execution failed", ex);

spring-core/src/main/java/org/springframework/core/ReactiveTypeDescriptor.java

@@ -28,7 +28,7 @@ import org.springframework.util.Assert;
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-public class ReactiveTypeDescriptor {
+public final class ReactiveTypeDescriptor {
 
 	private final Class<?> reactiveType;
 

spring-core/src/main/java/org/springframework/core/SpringVersion.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -31,7 +31,12 @@ import org.springframework.lang.Nullable;
  * @author Juergen Hoeller
  * @since 1.1
  */
-public class SpringVersion {
+public final class SpringVersion {
+
+
+	private SpringVersion() {
+	}
+
 
 	/**
 	 * Return the full version string of the present Spring codebase,

spring-core/src/main/java/org/springframework/core/annotation/AnnotationUtils.java

@@ -2047,7 +2047,7 @@ public abstract class AnnotationUtils {
 	 * @see #getAttributeAliasNames
 	 * @see #getAttributeOverrideName
 	 */
-	private static class AliasDescriptor {
+	private static final class AliasDescriptor {
 
 		private final Method sourceAttribute;
 

spring-core/src/main/java/org/springframework/core/codec/CharSequenceEncoder.java

@@ -42,7 +42,7 @@ import org.springframework.util.MimeTypeUtils;
  * @since 5.0
  * @see StringDecoder
  */
-public class CharSequenceEncoder extends AbstractEncoder<CharSequence> {
+public final class CharSequenceEncoder extends AbstractEncoder<CharSequence> {
 
 	/**
 	 * The default charset used by the encoder.

spring-core/src/main/java/org/springframework/core/codec/StringDecoder.java

@@ -53,7 +53,7 @@ import org.springframework.util.MimeTypeUtils;
  * @since 5.0
  * @see CharSequenceEncoder
  */
-public class StringDecoder extends AbstractDataBufferDecoder<String> {
+public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 
 	private static final DataBuffer END_FRAME = new DefaultDataBufferFactory().wrap(new byte[0]);
 

spring-core/src/main/java/org/springframework/core/env/ProfilesParser.java

@@ -31,7 +31,10 @@ import org.springframework.util.StringUtils;
  * @author Phillip Webb
  * @since 5.1
  */
-class ProfilesParser {
+final class ProfilesParser {
+
+	private ProfilesParser() {
+	}
 
 	static Profiles parse(String... expressions) {
 		Assert.notEmpty(expressions, "Must specify at least one profile");

spring-core/src/main/java/org/springframework/util/ReflectionUtils.java

@@ -57,6 +57,27 @@ public abstract class ReflectionUtils {
 
 	private static final Field[] NO_FIELDS = {};
 
+	/**
+	 * Pre-built FieldFilter that matches all non-static, non-final fields.
+	 */
+	public static final FieldFilter COPYABLE_FIELDS =
+			field -> !(Modifier.isStatic(field.getModifiers()) || Modifier.isFinal(field.getModifiers()));
+
+
+	/**
+	 * Pre-built MethodFilter that matches all non-bridge methods.
+	 */
+	public static final MethodFilter NON_BRIDGED_METHODS =
+			(method -> !method.isBridge());
+
+
+	/**
+	 * Pre-built MethodFilter that matches all non-bridge non-synthetic methods
+	 * which are not declared on {@code java.lang.Object}.
+	 */
+	public static final MethodFilter USER_DECLARED_METHODS =
+			(method -> (!method.isBridge() && !method.isSynthetic() && method.getDeclaringClass() != Object.class));
+
 
 	/**
 	 * Cache for {@link Class#getDeclaredMethods()} plus equivalent default methods
@@ -847,25 +868,4 @@ public abstract class ReflectionUtils {
 	}
 
 
-	/**
-	 * Pre-built FieldFilter that matches all non-static, non-final fields.
-	 */
-	public static final FieldFilter COPYABLE_FIELDS =
-			field -> !(Modifier.isStatic(field.getModifiers()) || Modifier.isFinal(field.getModifiers()));
-
-
-	/**
-	 * Pre-built MethodFilter that matches all non-bridge methods.
-	 */
-	public static final MethodFilter NON_BRIDGED_METHODS =
-			(method -> !method.isBridge());
-
-
-	/**
-	 * Pre-built MethodFilter that matches all non-bridge non-synthetic methods
-	 * which are not declared on {@code java.lang.Object}.
-	 */
-	public static final MethodFilter USER_DECLARED_METHODS =
-			(method -> (!method.isBridge() && !method.isSynthetic() && method.getDeclaringClass() != Object.class));
-
 }

spring-expression/src/main/java/org/springframework/expression/ExpressionException.java

@@ -29,7 +29,7 @@ import org.springframework.lang.Nullable;
 public class ExpressionException extends RuntimeException {
 
 	@Nullable
-	protected String expressionString;
+	protected final String expressionString;
 
 	protected int position;  // -1 if not known; should be known in all reasonable cases
 
@@ -40,6 +40,8 @@ public class ExpressionException extends RuntimeException {
 	 */
 	public ExpressionException(String message) {
 		super(message);
+		this.expressionString = null;
+		this.position = 0;
 	}
 
 	/**
@@ -49,6 +51,8 @@ public class ExpressionException extends RuntimeException {
 	 */
 	public ExpressionException(String message, Throwable cause) {
 		super(message, cause);
+		this.expressionString = null;
+		this.position = 0;
 	}
 
 	/**
@@ -81,6 +85,7 @@ public class ExpressionException extends RuntimeException {
 	 */
 	public ExpressionException(int position, String message) {
 		super(message);
+		this.expressionString = null;
 		this.position = position;
 	}
 
@@ -92,6 +97,7 @@ public class ExpressionException extends RuntimeException {
 	 */
 	public ExpressionException(int position, String message, Throwable cause) {
 		super(message, cause);
+		this.expressionString = null;
 		this.position = position;
 	}
 

spring-expression/src/main/java/org/springframework/expression/spel/CodeFlow.java

@@ -1009,6 +1009,21 @@ public class CodeFlow implements Opcodes {
 		}
 	}
 
+	public static final String toBoxedDescriptor(String primitiveDescriptor) {
+		switch (primitiveDescriptor.charAt(0)) {
+			case 'I': return "Ljava/lang/Integer";
+			case 'J': return "Ljava/lang/Long";
+			case 'F': return "Ljava/lang/Float";
+			case 'D': return "Ljava/lang/Double";
+			case 'B': return "Ljava/lang/Byte";
+			case 'C': return "Ljava/lang/Character";
+			case 'S': return "Ljava/lang/Short";
+			case 'Z': return "Ljava/lang/Boolean";
+			default:
+				throw new IllegalArgumentException("Unexpected non primitive descriptor "+primitiveDescriptor);
+		}
+	}
+
 
 	/**
 	 * Interface used to generate fields.
@@ -1029,19 +1044,5 @@ public class CodeFlow implements Opcodes {
 		void generateCode(MethodVisitor mv, CodeFlow codeflow);
 	}
 
-	public static String toBoxedDescriptor(String primitiveDescriptor) {
-		switch (primitiveDescriptor.charAt(0)) {
-			case 'I': return "Ljava/lang/Integer";
-			case 'J': return "Ljava/lang/Long";
-			case 'F': return "Ljava/lang/Float";
-			case 'D': return "Ljava/lang/Double";
-			case 'B': return "Ljava/lang/Byte";
-			case 'C': return "Ljava/lang/Character";
-			case 'S': return "Ljava/lang/Short";
-			case 'Z': return "Ljava/lang/Boolean";
-			default:
-				throw new IllegalArgumentException("Unexpected non primitive descriptor "+primitiveDescriptor);
-		}	
-	}
 
 }

spring-expression/src/main/java/org/springframework/expression/spel/ast/Operator.java

@@ -41,7 +41,7 @@ import org.springframework.util.ObjectUtils;
 public abstract class Operator extends SpelNodeImpl {
 
 	private final String operatorName;
-	
+
 	// The descriptors of the runtime operand values are used if the discovered declared
 	// descriptors are not providing enough information (for example a generic type
 	// whose accessors seem to only be returning 'Object' - the actual descriptors may
@@ -104,8 +104,8 @@ public abstract class Operator extends SpelNodeImpl {
 		return (dc.areNumbers && dc.areCompatible);
 	}
 
-	/** 
+	/**
-	 * Numeric comparison operators share very similar generated code, only differing in 
+	 * Numeric comparison operators share very similar generated code, only differing in
 	 * two comparison instructions.
 	 */
 	protected void generateComparisonCode(MethodVisitor mv, CodeFlow cf, int compInstruction1, int compInstruction2) {
@@ -113,20 +113,20 @@ public abstract class Operator extends SpelNodeImpl {
 		SpelNodeImpl right = getRightOperand();
 		String leftDesc = left.exitTypeDescriptor;
 		String rightDesc = right.exitTypeDescriptor;
-		
+
 		boolean unboxLeft = !CodeFlow.isPrimitive(leftDesc);
 		boolean unboxRight = !CodeFlow.isPrimitive(rightDesc);
 		DescriptorComparison dc = DescriptorComparison.checkNumericCompatibility(
 				leftDesc, rightDesc, this.leftActualDescriptor, this.rightActualDescriptor);
 		char targetType = dc.compatibleType;  // CodeFlow.toPrimitiveTargetDesc(leftDesc);
-		
+
 		cf.enterCompilationScope();
 		left.generateCode(mv, cf);
 		cf.exitCompilationScope();
 		if (unboxLeft) {
 			CodeFlow.insertUnboxInsns(mv, targetType, leftDesc);
 		}
-	
+
 		cf.enterCompilationScope();
 		right.generateCode(mv, cf);
 		cf.exitCompilationScope();
@@ -142,11 +142,11 @@ public abstract class Operator extends SpelNodeImpl {
 			mv.visitJumpInsn(compInstruction1, elseTarget);
 		}
 		else if (targetType == 'F') {
-			mv.visitInsn(FCMPG);		
+			mv.visitInsn(FCMPG);
 			mv.visitJumpInsn(compInstruction1, elseTarget);
 		}
 		else if (targetType == 'J') {
-			mv.visitInsn(LCMP);		
+			mv.visitInsn(LCMP);
 			mv.visitJumpInsn(compInstruction1, elseTarget);
 		}
 		else if (targetType == 'I') {
@@ -231,13 +231,13 @@ public abstract class Operator extends SpelNodeImpl {
 
 		return false;
 	}
-	
+
 
 	/**
 	 * A descriptor comparison encapsulates the result of comparing descriptor
 	 * for two operands and describes at what level they are compatible.
 	 */
-	protected static class DescriptorComparison {
+	protected static final class DescriptorComparison {
 
 		static final DescriptorComparison NOT_NUMBERS = new DescriptorComparison(false, false, ' ');
 
@@ -254,7 +254,7 @@ public abstract class Operator extends SpelNodeImpl {
 			this.areCompatible = areCompatible;
 			this.compatibleType = compatibleType;
 		}
-		
+
 		/**
 		 * Return an object that indicates whether the input descriptors are compatible.
 		 * <p>A declared descriptor is what could statically be determined (e.g. from looking
@@ -278,7 +278,7 @@ public abstract class Operator extends SpelNodeImpl {
 
 			boolean leftNumeric = CodeFlow.isPrimitiveOrUnboxableSupportedNumberOrBoolean(ld);
 			boolean rightNumeric = CodeFlow.isPrimitiveOrUnboxableSupportedNumberOrBoolean(rd);
-			
+
 			// If the declared descriptors aren't providing the information, try the actual descriptors
 			if (!leftNumeric && !ObjectUtils.nullSafeEquals(ld, leftActualDescriptor)) {
 				ld = leftActualDescriptor;
@@ -288,7 +288,7 @@ public abstract class Operator extends SpelNodeImpl {
 				rd = rightActualDescriptor;
 				rightNumeric = CodeFlow.isPrimitiveOrUnboxableSupportedNumberOrBoolean(rd);
 			}
-			
+
 			if (leftNumeric && rightNumeric) {
 				if (CodeFlow.areBoxingCompatible(ld, rd)) {
 					return new DescriptorComparison(true, true, CodeFlow.toPrimitiveTargetDesc(ld));
@@ -299,7 +299,7 @@ public abstract class Operator extends SpelNodeImpl {
 			}
 			else {
 				return DescriptorComparison.NOT_NUMBERS;
-			}		
+			}
 		}
 	}
 

spring-expression/src/main/java/org/springframework/expression/spel/standard/SpelCompiler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -64,7 +64,7 @@ import org.springframework.util.ReflectionUtils;
  * @author Andy Clement
  * @since 4.1
  */
-public class SpelCompiler implements Opcodes {
+public final class SpelCompiler implements Opcodes {
 
 	private static final Log logger = LogFactory.getLog(SpelCompiler.class);
 

spring-expression/src/main/java/org/springframework/expression/spel/support/BooleanTypedValue.java

@@ -24,7 +24,7 @@ import org.springframework.expression.TypedValue;
  * @author Andy Clement
  * @since 3.0
  */
-public class BooleanTypedValue extends TypedValue {
+public final class BooleanTypedValue extends TypedValue {
 
 	/**
 	 * True.

spring-expression/src/main/java/org/springframework/expression/spel/support/DataBindingMethodResolver.java

@@ -39,7 +39,7 @@ import org.springframework.lang.Nullable;
  * @see #forInstanceMethodInvocation()
  * @see DataBindingPropertyAccessor
  */
-public class DataBindingMethodResolver extends ReflectiveMethodResolver {
+public final class DataBindingMethodResolver extends ReflectiveMethodResolver {
 
 	private DataBindingMethodResolver() {
 		super();

spring-expression/src/main/java/org/springframework/expression/spel/support/DataBindingPropertyAccessor.java

@@ -37,7 +37,7 @@ import java.lang.reflect.Method;
  * @see StandardEvaluationContext
  * @see ReflectivePropertyAccessor
  */
-public class DataBindingPropertyAccessor extends ReflectivePropertyAccessor {
+public final class DataBindingPropertyAccessor extends ReflectivePropertyAccessor {
 
 	/**
 	 * Create a new property accessor for reading and possibly also writing.

spring-expression/src/main/java/org/springframework/expression/spel/support/SimpleEvaluationContext.java

@@ -86,7 +86,7 @@ import org.springframework.lang.Nullable;
  * @see StandardTypeConverter
  * @see DataBindingPropertyAccessor
  */
-public class SimpleEvaluationContext implements EvaluationContext {
+public final class SimpleEvaluationContext implements EvaluationContext {
 
 	private static final TypeLocator typeNotFoundTypeLocator = typeName -> {
 		throw new SpelEvaluationException(SpelMessage.TYPE_NOT_FOUND, typeName);

spring-instrument/src/main/java/org/springframework/instrument/InstrumentationSavingAgent.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -27,11 +27,15 @@ import java.lang.instrument.Instrumentation;
  * @since 2.0
  * @see org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver
  */
-public class InstrumentationSavingAgent {
+public final class InstrumentationSavingAgent {
 
 	private static volatile Instrumentation instrumentation;
 
 
+	private InstrumentationSavingAgent() {
+	}
+
+
 	/**
 	 * Save the {@link Instrumentation} interface exposed by the JVM.
 	 */

spring-jdbc/src/main/java/org/springframework/jdbc/BadSqlGrammarException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -34,7 +34,7 @@ import org.springframework.dao.InvalidDataAccessResourceUsageException;
 @SuppressWarnings("serial")
 public class BadSqlGrammarException extends InvalidDataAccessResourceUsageException {
 
-	private String sql;
+	private final String sql;
 
 
 	/**

spring-jdbc/src/main/java/org/springframework/jdbc/IncorrectResultSetColumnCountException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -29,9 +29,9 @@ import org.springframework.dao.DataRetrievalFailureException;
 @SuppressWarnings("serial")
 public class IncorrectResultSetColumnCountException extends DataRetrievalFailureException {
 
-	private int expectedCount;
+	private final int expectedCount;
 
-	private int actualCount;
+	private final int actualCount;
 
 
 	/**

spring-jdbc/src/main/java/org/springframework/jdbc/InvalidResultSetAccessException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -37,7 +37,7 @@ import org.springframework.lang.Nullable;
 public class InvalidResultSetAccessException extends InvalidDataAccessResourceUsageException {
 
 	@Nullable
-	private String sql;
+	private final String sql;
 
 
 	/**
@@ -57,6 +57,7 @@ public class InvalidResultSetAccessException extends InvalidDataAccessResourceUs
 	 */
 	public InvalidResultSetAccessException(SQLException ex) {
 		super(ex.getMessage(), ex);
+		this.sql = null;
 	}
 
 

spring-jdbc/src/main/java/org/springframework/jdbc/JdbcUpdateAffectedIncorrectNumberOfRowsException.java

@@ -30,10 +30,10 @@ import org.springframework.dao.IncorrectUpdateSemanticsDataAccessException;
 public class JdbcUpdateAffectedIncorrectNumberOfRowsException extends IncorrectUpdateSemanticsDataAccessException {
 
 	/** Number of rows that should have been affected. */
-	private int expected;
+	private final int expected;
 
 	/** Number of rows that actually were affected. */
-	private int actual;
+	private final int actual;
 
 
 	/**

spring-jdbc/src/main/java/org/springframework/jdbc/config/DatabasePopulatorConfigUtils.java

@@ -38,7 +38,12 @@ import org.springframework.util.xml.DomUtils;
  * @author Stephane Nicoll
  * @since 3.1
  */
-class DatabasePopulatorConfigUtils {
+final class DatabasePopulatorConfigUtils {
+
+
+	private DatabasePopulatorConfigUtils() {
+	}
+
 
 	public static void setDatabasePopulator(Element element, BeanDefinitionBuilder builder) {
 		List<Element> scripts = DomUtils.getChildElementsByTagName(element, "script");

spring-jdbc/src/main/java/org/springframework/jdbc/core/metadata/CallMetaDataProviderFactory.java

@@ -35,7 +35,7 @@ import org.springframework.jdbc.support.MetaDataAccessException;
  * @author Juergen Hoeller
  * @since 2.5
  */
-public class CallMetaDataProviderFactory {
+public final class CallMetaDataProviderFactory {
 
 	/** List of supported database products for procedure calls. */
 	public static final List<String> supportedDatabaseProductsForProcedures = Arrays.asList(
@@ -59,6 +59,10 @@ public class CallMetaDataProviderFactory {
 	private static final Log logger = LogFactory.getLog(CallMetaDataProviderFactory.class);
 
 
+	private CallMetaDataProviderFactory() {
+	}
+
+
 	/**
 	 * Create a {@link CallMetaDataProvider} based on the database meta-data.
 	 * @param dataSource the JDBC DataSource to use for retrieving meta-data

spring-jdbc/src/main/java/org/springframework/jdbc/core/metadata/TableMetaDataProviderFactory.java

@@ -32,11 +32,15 @@ import org.springframework.jdbc.support.MetaDataAccessException;
  * @author Thomas Risberg
  * @since 2.5
  */
-public class TableMetaDataProviderFactory {
+public final class TableMetaDataProviderFactory {
 
 	private static final Log logger = LogFactory.getLog(TableMetaDataProviderFactory.class);
 
 
+	private TableMetaDataProviderFactory() {
+	}
+
+
 	/**
 	 * Create a {@link TableMetaDataProvider} based on the database meta-data.
 	 * @param dataSource used to retrieve meta-data

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/UserCredentialsDataSourceAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -202,7 +202,7 @@ public class UserCredentialsDataSourceAdapter extends DelegatingDataSource {
 	/**
 	 * Inner class used as ThreadLocal value.
 	 */
-	private static class JdbcUserCredentials {
+	private static final class JdbcUserCredentials {
 
 		public final String username;
 

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/embedded/EmbeddedDatabaseConfigurerFactory.java

@@ -29,6 +29,11 @@ import org.springframework.util.Assert;
  */
 final class EmbeddedDatabaseConfigurerFactory {
 
+
+	private EmbeddedDatabaseConfigurerFactory() {
+	}
+
+
 	/**
 	 * Return a configurer instance for the given embedded database type.
 	 * @param type the embedded database type (HSQL, H2 or Derby)

spring-jdbc/src/main/java/org/springframework/jdbc/datasource/embedded/OutputStreamFactory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -26,7 +26,12 @@ import java.io.OutputStream;
  * @author Juergen Hoeller
  * @since 3.0
  */
-public class OutputStreamFactory {
+public final class OutputStreamFactory {
+
+
+	private OutputStreamFactory() {
+	}
+
 
 	/**
 	 * Returns an {@link java.io.OutputStream} that ignores all data given to it.

spring-jdbc/src/main/java/org/springframework/jdbc/support/CustomSQLExceptionTranslatorRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -33,7 +33,7 @@ import org.springframework.lang.Nullable;
  * @since 3.1.1
  * @see SQLErrorCodesFactory
  */
-public class CustomSQLExceptionTranslatorRegistry {
+public final class CustomSQLExceptionTranslatorRegistry {
 
 	private static final Log logger = LogFactory.getLog(CustomSQLExceptionTranslatorRegistry.class);
 

spring-jms/src/main/java/org/springframework/jms/connection/UserCredentialsConnectionFactoryAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -320,17 +320,19 @@ public class UserCredentialsConnectionFactoryAdapter
 	/**
 	 * Inner class used as ThreadLocal value.
 	 */
-	private static class JmsUserCredentials {
+	private static final class JmsUserCredentials {
 
 		public final String username;
 
 		public final String password;
 
+
 		private JmsUserCredentials(String username, String password) {
 			this.username = username;
 			this.password = password;
 		}
 
+
 		@Override
 		public String toString() {
 			return "JmsUserCredentials[username='" + this.username + "',password='" + this.password + "']";

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/DestinationVariableMethodArgumentResolver.java

@@ -78,7 +78,7 @@ public class DestinationVariableMethodArgumentResolver extends AbstractNamedValu
 	}
 
 
-	private static class DestinationVariableNamedValueInfo extends NamedValueInfo {
+	private static final class DestinationVariableNamedValueInfo extends NamedValueInfo {
 
 		private DestinationVariableNamedValueInfo(DestinationVariable annotation) {
 			super(annotation.value(), true, ValueConstants.DEFAULT_NONE);

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/HeaderMethodArgumentResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -106,7 +106,7 @@ public class HeaderMethodArgumentResolver extends AbstractNamedValueMethodArgume
 	}
 
 
-	private static class HeaderNamedValueInfo extends NamedValueInfo {
+	private static final class HeaderNamedValueInfo extends NamedValueInfo {
 
 		private HeaderNamedValueInfo(Header annotation) {
 			super(annotation.name(), annotation.required(), annotation.defaultValue());

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/support/MethodArgumentNotValidException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -34,7 +34,7 @@ import org.springframework.validation.ObjectError;
 @SuppressWarnings("serial")
 public class MethodArgumentNotValidException extends MethodArgumentResolutionException {
 
-	private BindingResult bindingResult;
+	private final BindingResult bindingResult;
 
 
 	/**
@@ -42,6 +42,7 @@ public class MethodArgumentNotValidException extends MethodArgumentResolutionExc
 	 */
 	public MethodArgumentNotValidException(Message<?> message, MethodParameter parameter) {
 		super(message, parameter);
+		this.bindingResult = null;
 	}
 
 	/**

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompBrokerRelayMessageHandler.java

@@ -577,7 +577,7 @@ public class StompBrokerRelayMessageHandler extends AbstractBrokerMessageHandler
 		private volatile boolean isStompConnected;
 
 
-		private StompConnectionHandler(String sessionId, StompHeaderAccessor connectHeaders) {
+		protected StompConnectionHandler(String sessionId, StompHeaderAccessor connectHeaders) {
 			this(sessionId, connectHeaders, true);
 		}
 

spring-orm/src/main/java/org/springframework/orm/ObjectOptimisticLockingFailureException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,10 +30,10 @@ import org.springframework.lang.Nullable;
 public class ObjectOptimisticLockingFailureException extends OptimisticLockingFailureException {
 
 	@Nullable
-	private Object persistentClass;
+	private final Object persistentClass;
 
 	@Nullable
-	private Object identifier;
+	private final Object identifier;
 
 
 	/**
@@ -44,6 +44,8 @@ public class ObjectOptimisticLockingFailureException extends OptimisticLockingFa
 	 */
 	public ObjectOptimisticLockingFailureException(String msg, Throwable cause) {
 		super(msg, cause);
+		this.persistentClass = null;
+		this.identifier = null;
 	}
 
 	/**

spring-orm/src/main/java/org/springframework/orm/ObjectRetrievalFailureException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -30,10 +30,10 @@ import org.springframework.lang.Nullable;
 public class ObjectRetrievalFailureException extends DataRetrievalFailureException {
 
 	@Nullable
-	private Object persistentClass;
+	private final Object persistentClass;
 
 	@Nullable
-	private Object identifier;
+	private final Object identifier;
 
 
 	/**
@@ -44,6 +44,8 @@ public class ObjectRetrievalFailureException extends DataRetrievalFailureExcepti
 	 */
 	public ObjectRetrievalFailureException(String msg, Throwable cause) {
 		super(msg, cause);
+		this.persistentClass = null;
+		this.identifier = null;
 	}
 
 	/**

spring-orm/src/main/java/org/springframework/orm/hibernate5/HibernateTransactionManager.java

@@ -890,7 +890,7 @@ public class HibernateTransactionManager extends AbstractPlatformTransactionMana
 	 * Holder for suspended resources.
 	 * Used internally by {@code doSuspend} and {@code doResume}.
 	 */
-	private static class SuspendedResourcesHolder {
+	private static final class SuspendedResourcesHolder {
 
 		private final SessionHolder sessionHolder;
 

spring-orm/src/main/java/org/springframework/orm/jpa/ExtendedEntityManagerCreator.java

@@ -242,7 +242,7 @@ public abstract class ExtendedEntityManagerCreator {
 	 * InvocationHandler for extended EntityManagers as defined in the JPA spec.
 	 */
 	@SuppressWarnings("serial")
-	private static class ExtendedEntityManagerInvocationHandler implements InvocationHandler, Serializable {
+	private static final class ExtendedEntityManagerInvocationHandler implements InvocationHandler, Serializable {
 
 		private static final Log logger = LogFactory.getLog(ExtendedEntityManagerInvocationHandler.class);
 

spring-orm/src/main/java/org/springframework/orm/jpa/JpaTransactionManager.java

@@ -745,7 +745,7 @@ public class JpaTransactionManager extends AbstractPlatformTransactionManager
 	 * Holder for suspended resources.
 	 * Used internally by {@code doSuspend} and {@code doResume}.
 	 */
-	private static class SuspendedResourcesHolder {
+	private static final class SuspendedResourcesHolder {
 
 		private final EntityManagerHolder entityManagerHolder;
 

spring-oxm/src/main/java/org/springframework/oxm/jaxb/Jaxb2Marshaller.java

@@ -127,6 +127,9 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
 
 	private static final String CID = "cid:";
 
+	private static final EntityResolver NO_OP_ENTITY_RESOLVER =
+			(publicId, systemId) -> new InputSource(new StringReader(""));
+
 
 	/** Logger available to subclasses. */
 	protected final Log logger = LogFactory.getLog(getClass());
@@ -1079,8 +1082,4 @@ public class Jaxb2Marshaller implements MimeMarshaller, MimeUnmarshaller, Generi
 		}
 	}
 
-
-	private static final EntityResolver NO_OP_ENTITY_RESOLVER =
-			(publicId, systemId) -> new InputSource(new StringReader(""));
-
 }

spring-oxm/src/main/java/org/springframework/oxm/support/MarshallingSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -102,7 +102,7 @@ public class MarshallingSource extends SAXSource {
 	}
 
 
-	private static class MarshallingXMLReader implements XMLReader {
+	private static final class MarshallingXMLReader implements XMLReader {
 
 		private final Marshaller marshaller;
 

spring-test/src/main/java/org/springframework/mock/http/server/reactive/MockServerHttpRequest.java

@@ -52,7 +52,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  * @author Rossen Stoyanchev
  * @since 5.0
  */
-public class MockServerHttpRequest extends AbstractServerHttpRequest {
+public final class MockServerHttpRequest extends AbstractServerHttpRequest {
 
 	private final HttpMethod httpMethod;
 

spring-test/src/main/java/org/springframework/mock/jndi/SimpleNamingContext.java

@@ -357,7 +357,7 @@ public class SimpleNamingContext implements Context {
 	}
 
 
-	private static class NameClassPairEnumeration extends AbstractNamingEnumeration<NameClassPair> {
+	private static final class NameClassPairEnumeration extends AbstractNamingEnumeration<NameClassPair> {
 
 		private NameClassPairEnumeration(SimpleNamingContext context, String root) throws NamingException {
 			super(context, root);
@@ -370,7 +370,7 @@ public class SimpleNamingContext implements Context {
 	}
 
 
-	private static class BindingEnumeration extends AbstractNamingEnumeration<Binding> {
+	private static final class BindingEnumeration extends AbstractNamingEnumeration<Binding> {
 
 		private BindingEnumeration(SimpleNamingContext context, String root) throws NamingException {
 			super(context, root);

spring-test/src/main/java/org/springframework/mock/web/MockFilterChain.java

@@ -150,7 +150,7 @@ public class MockFilterChain implements FilterChain {
 	/**
 	 * A filter that simply delegates to a Servlet.
 	 */
-	private static class ServletFilterProxy implements Filter {
+	private static final class ServletFilterProxy implements Filter {
 
 		private final Servlet delegateServlet;
 

spring-test/src/main/java/org/springframework/mock/web/reactive/function/server/MockServerRequest.java

@@ -63,7 +63,7 @@ import org.springframework.web.util.UriComponentsBuilder;
  * @author Arjen Poutsma
  * @since 5.0
  */
-public class MockServerRequest implements ServerRequest {
+public final class MockServerRequest implements ServerRequest {
 
 	private final HttpMethod method;
 

spring-test/src/main/java/org/springframework/test/annotation/SystemProfileValueSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -26,7 +26,7 @@ import org.springframework.util.Assert;
  * @author Sam Brannen
  * @since 2.0
  */
-public class SystemProfileValueSource implements ProfileValueSource {
+public final class SystemProfileValueSource implements ProfileValueSource {
 
 	private static final SystemProfileValueSource INSTANCE = new SystemProfileValueSource();
 

spring-test/src/main/java/org/springframework/test/annotation/TestAnnotationUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -26,7 +26,12 @@ import org.springframework.core.annotation.AnnotatedElementUtils;
  * @author Sam Brannen
  * @since 4.2
  */
-public class TestAnnotationUtils {
+public final class TestAnnotationUtils {
+
+
+	private TestAnnotationUtils() {
+	}
+
 
 	/**
 	 * Get the {@code timeout} configured via the {@link Timed @Timed}

spring-test/src/main/java/org/springframework/test/context/transaction/TestTransaction.java

@@ -38,7 +38,12 @@ import org.springframework.util.Assert;
  * @since 4.1
  * @see TransactionalTestExecutionListener
  */
-public class TestTransaction {
+public final class TestTransaction {
+
+
+	private TestTransaction() {
+	}
+
 
 	/**
 	 * Determine whether a test-managed transaction is currently <em>active</em>.

spring-test/src/main/java/org/springframework/test/context/transaction/TransactionContextHolder.java

@@ -25,12 +25,16 @@ import org.springframework.lang.Nullable;
  * @author Sam Brannen
  * @since 4.1
  */
-class TransactionContextHolder {
+final class TransactionContextHolder {
 
 	private static final ThreadLocal<TransactionContext> currentTransactionContext =
 			new NamedInheritableThreadLocal<>("Test Transaction Context");
 
 
+	private TransactionContextHolder() {
+	}
+
+
 	static void setCurrentTransactionContext(TransactionContext transactionContext) {
 		currentTransactionContext.set(transactionContext);
 	}

spring-test/src/main/java/org/springframework/test/jdbc/JdbcTestUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -38,11 +38,15 @@ import org.springframework.util.StringUtils;
  * @see org.springframework.jdbc.datasource.init.ResourceDatabasePopulator
  * @see org.springframework.jdbc.datasource.init.DatabasePopulatorUtils
  */
-public class JdbcTestUtils {
+public final class JdbcTestUtils {
 
 	private static final Log logger = LogFactory.getLog(JdbcTestUtils.class);
 
 
+	private JdbcTestUtils() {
+	}
+
+
 	/**
 	 * Count the rows in the given table.
 	 * @param jdbcTemplate the JdbcTemplate with which to perform JDBC operations

spring-test/src/main/java/org/springframework/test/web/client/ExpectedCount.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -38,7 +38,7 @@ import org.springframework.util.Assert;
  * @author Rossen Stoyanchev
  * @since 4.3
  */
-public class ExpectedCount {
+public final class ExpectedCount {
 
 	private final int minCount;
 

spring-test/src/main/java/org/springframework/test/web/client/MockRestServiceServer.java

@@ -64,7 +64,7 @@ import org.springframework.web.client.support.RestGatewaySupport;
  * @since 3.2
  */
 @SuppressWarnings("deprecation")
-public class MockRestServiceServer {
+public final class MockRestServiceServer {
 
 	private final RequestExpectationManager expectationManager;
 

spring-test/src/main/java/org/springframework/test/web/servlet/setup/MockMvcBuilders.java

@@ -33,7 +33,12 @@ import org.springframework.web.context.WebApplicationContext;
  * @see #webAppContextSetup(WebApplicationContext)
  * @see #standaloneSetup(Object...)
  */
-public class MockMvcBuilders {
+public final class MockMvcBuilders {
+
+
+	private MockMvcBuilders() {
+	}
+
 
 	/**
 	 * Build a {@link MockMvc} instance using the given, fully initialized

spring-tx/src/main/java/org/springframework/dao/IncorrectResultSizeDataAccessException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -28,9 +28,9 @@ package org.springframework.dao;
 @SuppressWarnings("serial")
 public class IncorrectResultSizeDataAccessException extends DataRetrievalFailureException {
 
-	private int expectedSize;
+	private final int expectedSize;
 
-	private int actualSize;
+	private final int actualSize;
 
 
 	/**

spring-tx/src/main/java/org/springframework/jca/cci/connection/SingleConnectionFactory.java

@@ -225,7 +225,7 @@ public class SingleConnectionFactory extends DelegatingConnectionFactory impleme
 	/**
 	 * Invocation handler that suppresses close calls on CCI Connections.
 	 */
-	private static class CloseSuppressingInvocationHandler implements InvocationHandler {
+	private static final class CloseSuppressingInvocationHandler implements InvocationHandler {
 
 		private final Connection target;
 

spring-tx/src/main/java/org/springframework/transaction/HeuristicCompletionException.java

@@ -65,7 +65,7 @@ public class HeuristicCompletionException extends TransactionException {
 	/**
 	 * The outcome state of the transaction: have some or all resources been committed?
 	 */
-	private int outcomeState = STATE_UNKNOWN;
+	private final int outcomeState;
 
 
 	/**

spring-tx/src/main/java/org/springframework/transaction/InvalidTimeoutException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -27,7 +27,7 @@ package org.springframework.transaction;
 @SuppressWarnings("serial")
 public class InvalidTimeoutException extends TransactionUsageException {
 
-	private int timeout;
+	private final int timeout;
 
 
 	/**

spring-tx/src/main/java/org/springframework/transaction/support/AbstractPlatformTransactionManager.java

@@ -1273,7 +1273,7 @@ public abstract class AbstractPlatformTransactionManager implements PlatformTran
 	 * Holder for suspended resources.
 	 * Used internally by {@code suspend} and {@code resume}.
 	 */
-	protected static class SuspendedResourcesHolder {
+	protected static final class SuspendedResourcesHolder {
 
 		@Nullable
 		private final Object suspendedResources;

spring-web/src/main/java/org/springframework/http/ContentDisposition.java

@@ -39,7 +39,7 @@ import static java.time.format.DateTimeFormatter.*;
  * @since 5.0
  * @see <a href="https://tools.ietf.org/html/rfc2183">RFC 2183</a>
  */
-public class ContentDisposition {
+public final class ContentDisposition {
 
 	@Nullable
 	private final String type;