Backport selected refinements from the nullability efforts

Issue: SPR-15656

Author: jhoeller

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

@@ -1,5 +1,5 @@
 /*<
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -34,19 +34,17 @@ public interface TargetSource extends TargetClassAware {
 
 	/**
 	 * Return the type of targets returned by this {@link TargetSource}.
-	 * <p>Can return {@code null}, although certain usages of a
-	 * {@code TargetSource} might just work with a predetermined
-	 * target class.
+	 * <p>Can return {@code null}, although certain usages of a {@code TargetSource}
+	 * might just work with a predetermined target class.
 	 * @return the type of targets returned by this {@link TargetSource}
 	 */
 	@Override
 	Class<?> getTargetClass();
 
 	/**
 	 * Will all calls to {@link #getTarget()} return the same object?
-	 * <p>In that case, there will be no need to invoke
-	 * {@link #releaseTarget(Object)}, and the AOP framework can cache
-	 * the return value of {@link #getTarget()}.
+	 * <p>In that case, there will be no need to invoke {@link #releaseTarget(Object)},
+	 * and the AOP framework can cache the return value of {@link #getTarget()}.
 	 * @return {@code true} if the target is immutable
 	 * @see #getTarget
 	 */
@@ -55,14 +53,15 @@ public interface TargetSource extends TargetClassAware {
 	/**
 	 * Return a target instance. Invoked immediately before the
 	 * AOP framework calls the "target" of an AOP method invocation.
-	 * @return the target object, which contains the joinpoint
+	 * @return the target object which contains the joinpoint,
+	 * or {@code null} if there is no actual target instance
 	 * @throws Exception if the target object can't be resolved
 	 */
 	Object getTarget() throws Exception;
 
 	/**
 	 * Release the given target object obtained from the
-	 * {@link #getTarget()} method.
+	 * {@link #getTarget()} method, if any.
 	 * @param target object obtained from a call to {@link #getTarget()}
 	 * @throws Exception if the object can't be released
 	 */

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -103,8 +103,8 @@ public static JoinPoint currentJoinPoint() {
 	private final AspectInstanceFactory aspectInstanceFactory;
 
 	/**
-	 * The name of the aspect (ref bean) in which this advice was defined (used
-	 * when determining advice precedence so that we can determine
+	 * The name of the aspect (ref bean) in which this advice was defined
+	 * (used when determining advice precedence so that we can determine
 	 * whether two pieces of advice come from the same aspect).
 	 */
 	private String aspectName;
@@ -118,13 +118,13 @@ public static JoinPoint currentJoinPoint() {
 	 * This will be non-null if the creator of this advice object knows the argument names
 	 * and sets them explicitly
 	 */
-	private String[] argumentNames = null;
+	private String[] argumentNames;
 
 	/** Non-null if after throwing advice binds the thrown value */
-	private String throwingName = null;
+	private String throwingName;
 
 	/** Non-null if after returning advice binds the return value */
-	private String returningName = null;
+	private String returningName;
 
 	private Class<?> discoveredReturningType = Object.class;
 
@@ -295,8 +295,8 @@ protected void setReturningNameNoCheck(String name) {
 			}
 			catch (Throwable ex) {
 				throw new IllegalArgumentException("Returning name '" + name  +
-						"' is neither a valid argument name nor the fully-qualified name of a Java type on the classpath. " +
-						"Root cause: " + ex);
+						"' is neither a valid argument name nor the fully-qualified " +
+						"name of a Java type on the classpath. Root cause: " + ex);
 			}
 		}
 	}
@@ -329,8 +329,8 @@ protected void setThrowingNameNoCheck(String name) {
 			}
 			catch (Throwable ex) {
 				throw new IllegalArgumentException("Throwing name '" + name  +
-						"' is neither a valid argument name nor the fully-qualified name of a Java type on the classpath. " +
-						"Root cause: " + ex);
+						"' is neither a valid argument name nor the fully-qualified " +
+						"name of a Java type on the classpath. Root cause: " + ex);
 			}
 		}
 	}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -113,6 +113,7 @@
  * returning {@code null} in the case that the parameter names cannot be discovered.
  *
  * @author Adrian Colyer
+ * @author Juergen Hoeller
  * @since 2.0
  */
 public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscoverer {
@@ -154,23 +155,17 @@ public class AspectJAdviceParameterNameDiscoverer implements ParameterNameDiscov
 	}
 
 
+	/** The pointcut expression associated with the advice, as a simple String */
+	private String pointcutExpression;
+
 	private boolean raiseExceptions;
 
-	/**
-	 * If the advice is afterReturning, and binds the return value, this is the parameter name used.
-	 */
+	/** If the advice is afterReturning, and binds the return value, this is the parameter name used */
 	private String returningName;
 
-	/**
-	 * If the advice is afterThrowing, and binds the thrown value, this is the parameter name used.
-	 */
+	/** If the advice is afterThrowing, and binds the thrown value, this is the parameter name used */
 	private String throwingName;
 
-	/**
-	 * The pointcut expression associated with the advice, as a simple String.
-	 */
-	private String pointcutExpression;
-
 	private Class<?>[] argumentTypes;
 
 	private String[] parameterNameBindings;
@@ -186,6 +181,7 @@ public AspectJAdviceParameterNameDiscoverer(String pointcutExpression) {
 		this.pointcutExpression = pointcutExpression;
 	}
 
+
 	/**
 	 * Indicate whether {@link IllegalArgumentException} and {@link AmbiguousBindingException}
 	 * must be thrown as appropriate in the case of failing to deduce advice parameter names.
@@ -213,6 +209,7 @@ public void setThrowingName(String throwingName) {
 		this.throwingName = throwingName;
 	}
 
+
 	/**
 	 * Deduce the parameter names for an advice method.
 	 * <p>See the {@link AspectJAdviceParameterNameDiscoverer class level javadoc}
@@ -474,7 +471,7 @@ else if (numAnnotationSlots == 1) {
 	 * If the token starts meets Java identifier conventions, it's in.
 	 */
 	private String maybeExtractVariableName(String candidateToken) {
-		if (candidateToken == null || candidateToken.equals("")) {
+		if (!StringUtils.hasLength(candidateToken)) {
 			return null;
 		}
 		if (Character.isJavaIdentifierStart(candidateToken.charAt(0)) &&

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -454,10 +454,7 @@ protected Object createProxy(
 		}
 
 		Advisor[] advisors = buildAdvisors(beanName, specificInterceptors);
-		for (Advisor advisor : advisors) {
-			proxyFactory.addAdvisor(advisor);
-		}
-
+		proxyFactory.addAdvisors(advisors);
 		proxyFactory.setTargetSource(targetSource);
 		customizeProxyFactory(proxyFactory);
 

spring-aop/src/main/java/org/springframework/aop/support/ComposablePointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 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 +22,6 @@
 import org.springframework.aop.MethodMatcher;
 import org.springframework.aop.Pointcut;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Convenient class for building up pointcuts. All methods return
@@ -188,21 +187,14 @@ public boolean equals(Object other) {
 		if (!(other instanceof ComposablePointcut)) {
 			return false;
 		}
-		ComposablePointcut that = (ComposablePointcut) other;
-		return ObjectUtils.nullSafeEquals(that.classFilter, this.classFilter) &&
-				ObjectUtils.nullSafeEquals(that.methodMatcher, this.methodMatcher);
+		ComposablePointcut otherPointcut = (ComposablePointcut) other;
+		return (this.classFilter.equals(otherPointcut.classFilter) &&
+				this.methodMatcher.equals(otherPointcut.methodMatcher));
 	}
 
 	@Override
 	public int hashCode() {
-		int code = 17;
-		if (this.classFilter != null) {
-			code = 37 * code + this.classFilter.hashCode();
-		}
-		if (this.methodMatcher != null) {
-			code = 37 * code + this.methodMatcher.hashCode();
-		}
-		return code;
+		return this.classFilter.hashCode() * 37 + this.methodMatcher.hashCode();
 	}
 
 	@Override

spring-aop/src/main/java/org/springframework/aop/support/NameMatchMethodPointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2014 the original author or authors.
+ * Copyright 2002-2017 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.

spring-aop/src/main/java/org/springframework/aop/support/annotation/AnnotationMatchingPointcut.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2013 the original author or authors.
+ * Copyright 2002-2017 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 +22,6 @@
 import org.springframework.aop.MethodMatcher;
 import org.springframework.aop.Pointcut;
 import org.springframework.util.Assert;
-import org.springframework.util.ObjectUtils;
 
 /**
  * Simple Pointcut that looks for a specific Java 5 annotation
@@ -46,16 +45,15 @@ public class AnnotationMatchingPointcut implements Pointcut {
 	 * @param classAnnotationType the annotation type to look for at the class level
 	 */
 	public AnnotationMatchingPointcut(Class<? extends Annotation> classAnnotationType) {
-		this.classFilter = new AnnotationClassFilter(classAnnotationType);
-		this.methodMatcher = MethodMatcher.TRUE;
+		this(classAnnotationType, false);
 	}
 
 	/**
 	 * Create a new AnnotationMatchingPointcut for the given annotation type.
 	 * @param classAnnotationType the annotation type to look for at the class level
-	 * @param checkInherited whether to explicitly check the superclasses and
-	 * interfaces for the annotation type as well (even if the annotation type
-	 * is not marked as inherited itself)
+	 * @param checkInherited whether to also check the superclasses and interfaces
+	 * as well as meta-annotations for the annotation type
+	 * @see AnnotationClassFilter#AnnotationClassFilter(Class, boolean)
 	 */
 	public AnnotationMatchingPointcut(Class<? extends Annotation> classAnnotationType, boolean checkInherited) {
 		this.classFilter = new AnnotationClassFilter(classAnnotationType, checkInherited);
@@ -109,21 +107,14 @@ public boolean equals(Object other) {
 		if (!(other instanceof AnnotationMatchingPointcut)) {
 			return false;
 		}
-		AnnotationMatchingPointcut that = (AnnotationMatchingPointcut) other;
-		return ObjectUtils.nullSafeEquals(that.classFilter, this.classFilter) &&
-				ObjectUtils.nullSafeEquals(that.methodMatcher, this.methodMatcher);
+		AnnotationMatchingPointcut otherPointcut = (AnnotationMatchingPointcut) other;
+		return (this.classFilter.equals(otherPointcut.classFilter) &&
+				this.methodMatcher.equals(otherPointcut.methodMatcher));
 	}
 
 	@Override
 	public int hashCode() {
-		int code = 17;
-		if (this.classFilter != null) {
-			code = 37 * code + this.classFilter.hashCode();
-		}
-		if (this.methodMatcher != null) {
-			code = 37 * code + this.methodMatcher.hashCode();
-		}
-		return code;
+		return this.classFilter.hashCode() * 37 + this.methodMatcher.hashCode();
 	}
 
 	@Override

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -81,8 +81,6 @@ public interface PropertyAccessor {
 	 * (may be a nested path and/or an indexed/mapped property)
 	 * @return the property type for the particular property,
 	 * or {@code null} if not determinable
-	 * @throws InvalidPropertyException if there is no such property or
-	 * if the property isn't readable
 	 * @throws PropertyAccessException if the property was valid but the
 	 * accessor method failed
 	 */
@@ -95,8 +93,8 @@ public interface PropertyAccessor {
 	 * (may be a nested path and/or an indexed/mapped property)
 	 * @return the property type for the particular property,
 	 * or {@code null} if not determinable
-	 * @throws InvalidPropertyException if there is no such property or
-	 * if the property isn't readable
+	 * @throws PropertyAccessException if the property was valid but the
+	 * accessor method failed
 	 */
 	TypeDescriptor getPropertyTypeDescriptor(String propertyName) throws BeansException;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -158,6 +158,22 @@ public interface BeanFactory {
 	 */
 	<T> T getBean(String name, Class<T> requiredType) throws BeansException;
 
+	/**
+	 * Return an instance, which may be shared or independent, of the specified bean.
+	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,
+	 * overriding the specified default arguments (if any) in the bean definition.
+	 * @param name the name of the bean to retrieve
+	 * @param args arguments to use when creating a bean instance using explicit arguments
+	 * (only applied when creating a new instance as opposed to retrieving an existing one)
+	 * @return an instance of the bean
+	 * @throws NoSuchBeanDefinitionException if there is no such bean definition
+	 * @throws BeanDefinitionStoreException if arguments have been given but
+	 * the affected bean isn't a prototype
+	 * @throws BeansException if the bean could not be created
+	 * @since 2.5
+	 */
+	Object getBean(String name, Object... args) throws BeansException;
+
 	/**
 	 * Return the bean instance that uniquely matches the given object type, if any.
 	 * <p>This method goes into {@link ListableBeanFactory} by-type lookup territory
@@ -175,22 +191,6 @@ public interface BeanFactory {
 	 */
 	<T> T getBean(Class<T> requiredType) throws BeansException;
 
-	/**
-	 * Return an instance, which may be shared or independent, of the specified bean.
-	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,
-	 * overriding the specified default arguments (if any) in the bean definition.
-	 * @param name the name of the bean to retrieve
-	 * @param args arguments to use when creating a bean instance using explicit arguments
-	 * (only applied when creating a new instance as opposed to retrieving an existing one)
-	 * @return an instance of the bean
-	 * @throws NoSuchBeanDefinitionException if there is no such bean definition
-	 * @throws BeanDefinitionStoreException if arguments have been given but
-	 * the affected bean isn't a prototype
-	 * @throws BeansException if the bean could not be created
-	 * @since 2.5
-	 */
-	Object getBean(String name, Object... args) throws BeansException;
-
 	/**
 	 * Return an instance, which may be shared or independent, of the specified bean.
 	 * <p>Allows for specifying explicit constructor arguments / factory method arguments,