Consistent final declaration for static delegate classes

Issue: SPR-16968

spring-aop/src/main/java/org/springframework/aop/framework/AopContext.java

@@ -39,7 +39,7 @@ import org.springframework.lang.Nullable;
  * @author Juergen Hoeller
  * @since 13.03.2003
  */
-public abstract class AopContext {
+public final class AopContext {
 
 	/**
 	 * ThreadLocal holder for AOP proxy associated with this thread.
@@ -50,6 +50,10 @@ public abstract class AopContext {
 	private static final ThreadLocal<Object> currentProxy = new NamedThreadLocal<>("Current AOP proxy");
 
 
+	private AopContext() {
+	}
+
+
 	/**
 	 * Try to return the current AOP proxy. This method is usable only if the
 	 * calling method has been invoked via AOP, and the AOP framework has been set

spring-aop/src/main/java/org/springframework/aop/framework/adapter/GlobalAdvisorAdapterRegistry.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 +24,11 @@ package org.springframework.aop.framework.adapter;
  * @author Phillip Webb
  * @see DefaultAdvisorAdapterRegistry
  */
-public abstract class GlobalAdvisorAdapterRegistry {
+public final class GlobalAdvisorAdapterRegistry {
+
+	private GlobalAdvisorAdapterRegistry() {
+	}
+
 
 	/**
 	 * Keep track of a single instance so we can return it to classes that request it.