/*
 * Copyright 2002-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.aop.aspectj;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;

import org.aopalliance.aop.Advice;
import org.aopalliance.intercept.MethodInvocation;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.weaver.tools.JoinPointMatch;
import org.aspectj.weaver.tools.PointcutParameter;

import org.springframework.aop.AopInvocationException;
import org.springframework.aop.MethodMatcher;
import org.springframework.aop.Pointcut;
import org.springframework.aop.ProxyMethodInvocation;
import org.springframework.aop.interceptor.ExposeInvocationInterceptor;
import org.springframework.aop.support.ComposablePointcut;
import org.springframework.aop.support.MethodMatchers;
import org.springframework.aop.support.StaticMethodMatcher;
import org.springframework.core.DefaultParameterNameDiscoverer;
import org.springframework.core.ParameterNameDiscoverer;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.StringUtils;

Base class for AOP Alliance Advice classes wrapping an AspectJ aspect or an AspectJ-annotated advice method. 
Author:
Rod Johnson, Adrian Colyer, Juergen Hoeller, Ramnivas Laddad
Since:
2.0/**
 * Base class for AOP Alliance {@link org.aopalliance.aop.Advice} classes
 * wrapping an AspectJ aspect or an AspectJ-annotated advice method.
 *
 * @author Rod Johnson
 * @author Adrian Colyer
 * @author Juergen Hoeller
 * @author Ramnivas Laddad
 * @since 2.0
 */
@SuppressWarnings("serial")
public abstract class AbstractAspectJAdvice implements Advice, AspectJPrecedenceInformation, Serializable {

	
Key used in ReflectiveMethodInvocation userAttributes map for the current joinpoint.
/**
	 * Key used in ReflectiveMethodInvocation userAttributes map for the current joinpoint.
	 */
	protected static final String JOIN_POINT_KEY = JoinPoint.class.getName();


	
Lazily instantiate joinpoint for the current invocation.
Requires MethodInvocation to be bound with ExposeInvocationInterceptor.
Do not use if access is available to the current ReflectiveMethodInvocation
(in an around advice).
Returns:
current AspectJ joinpoint, or through an exception if we're not in a
Spring AOP invocation./**
	 * Lazily instantiate joinpoint for the current invocation.
	 * Requires MethodInvocation to be bound with ExposeInvocationInterceptor.
	 * <p>Do not use if access is available to the current ReflectiveMethodInvocation
	 * (in an around advice).
	 * @return current AspectJ joinpoint, or through an exception if we're not in a
	 * Spring AOP invocation.
	 */
	public static JoinPoint currentJoinPoint() {
		MethodInvocation mi = ExposeInvocationInterceptor.currentInvocation();
		if (!(mi instanceof ProxyMethodInvocation)) {
			throw new IllegalStateException("MethodInvocation is not a Spring ProxyMethodInvocation: " + mi);
		}
		ProxyMethodInvocation pmi = (ProxyMethodInvocation) mi;
		JoinPoint jp = (JoinPoint) pmi.getUserAttribute(JOIN_POINT_KEY);
		if (jp == null) {
			jp = new MethodInvocationProceedingJoinPoint(pmi);
			pmi.setUserAttribute(JOIN_POINT_KEY, jp);
		}
		return jp;
	}


	private final Class<?> declaringClass;

	private final String methodName;

	private final Class<?>[] parameterTypes;

	protected transient Method aspectJAdviceMethod;

	private final AspectJExpressionPointcut pointcut;

	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
whether two pieces of advice come from the same aspect).
/**
	 * 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 = "";

	
The order of declaration of this advice within the aspect.
/**
	 * The order of declaration of this advice within the aspect.
	 */
	private int declarationOrder;

	
This will be non-null if the creator of this advice object knows the argument names
and sets them explicitly.
/**
	 * This will be non-null if the creator of this advice object knows the argument names
	 * and sets them explicitly.
	 */
	@Nullable
	private String[] argumentNames;

	
Non-null if after throwing advice binds the thrown value. /** Non-null if after throwing advice binds the thrown value. */
	@Nullable
	private String throwingName;

	
Non-null if after returning advice binds the return value. /** Non-null if after returning advice binds the return value. */
	@Nullable
	private String returningName;

	private Class<?> discoveredReturningType = Object.class;

	private Class<?> discoveredThrowingType = Object.class;

	
Index for thisJoinPoint argument (currently only
supported at index 0 if present at all).
/**
	 * Index for thisJoinPoint argument (currently only
	 * supported at index 0 if present at all).
	 */
	private int joinPointArgumentIndex = -1;

	
Index for thisJoinPointStaticPart argument (currently only
supported at index 0 if present at all).
/**
	 * Index for thisJoinPointStaticPart argument (currently only
	 * supported at index 0 if present at all).
	 */
	private int joinPointStaticPartArgumentIndex = -1;

	@Nullable
	private Map<String, Integer> argumentBindings;

	private boolean argumentsIntrospected = false;

	@Nullable
	private Type discoveredReturningGenericType;
	// Note: Unlike return type, no such generic information is needed for the throwing type,
	// since Java doesn't allow exception types to be parameterized.


	
Create a new AbstractAspectJAdvice for the given advice method.
Params:
aspectJAdviceMethod – the AspectJ-style advice method
pointcut – the AspectJ expression pointcut
aspectInstanceFactory – the factory for aspect instances/**
	 * Create a new AbstractAspectJAdvice for the given advice method.
	 * @param aspectJAdviceMethod the AspectJ-style advice method
	 * @param pointcut the AspectJ expression pointcut
	 * @param aspectInstanceFactory the factory for aspect instances
	 */
	public AbstractAspectJAdvice(
			Method aspectJAdviceMethod, AspectJExpressionPointcut pointcut, AspectInstanceFactory aspectInstanceFactory) {

		Assert.notNull(aspectJAdviceMethod, "Advice method must not be null");
		this.declaringClass = aspectJAdviceMethod.getDeclaringClass();
		this.methodName = aspectJAdviceMethod.getName();
		this.parameterTypes = aspectJAdviceMethod.getParameterTypes();
		this.aspectJAdviceMethod = aspectJAdviceMethod;
		this.pointcut = pointcut;
		this.aspectInstanceFactory = aspectInstanceFactory;
	}


	
Return the AspectJ-style advice method.
/**
	 * Return the AspectJ-style advice method.
	 */
	public final Method getAspectJAdviceMethod() {
		return this.aspectJAdviceMethod;
	}

	
Return the AspectJ expression pointcut.
/**
	 * Return the AspectJ expression pointcut.
	 */
	public final AspectJExpressionPointcut getPointcut() {
		calculateArgumentBindings();
		return this.pointcut;
	}

	
Build a 'safe' pointcut that excludes the AspectJ advice method itself.
See Also:
getPointcut()
Returns:
a composable pointcut that builds on the original AspectJ expression pointcut/**
	 * Build a 'safe' pointcut that excludes the AspectJ advice method itself.
	 * @return a composable pointcut that builds on the original AspectJ expression pointcut
	 * @see #getPointcut()
	 */
	public final Pointcut buildSafePointcut() {
		Pointcut pc = getPointcut();
		MethodMatcher safeMethodMatcher = MethodMatchers.intersection(
				new AdviceExcludingMethodMatcher(this.aspectJAdviceMethod), pc.getMethodMatcher());
		return new ComposablePointcut(pc.getClassFilter(), safeMethodMatcher);
	}

	
Return the factory for aspect instances.
/**
	 * Return the factory for aspect instances.
	 */
	public final AspectInstanceFactory getAspectInstanceFactory() {
		return this.aspectInstanceFactory;
	}

	
Return the ClassLoader for aspect instances.
/**
	 * Return the ClassLoader for aspect instances.
	 */
	@Nullable
	public final ClassLoader getAspectClassLoader() {
		return this.aspectInstanceFactory.getAspectClassLoader();
	}

	@Override
	public int getOrder() {
		return this.aspectInstanceFactory.getOrder();
	}


	
Set the name of the aspect (bean) in which the advice was declared.
/**
	 * Set the name of the aspect (bean) in which the advice was declared.
	 */
	public void setAspectName(String name) {
		this.aspectName = name;
	}

	@Override
	public String getAspectName() {
		return this.aspectName;
	}

	
Set the declaration order of this advice within the aspect.
/**
	 * Set the declaration order of this advice within the aspect.
	 */
	public void setDeclarationOrder(int order) {
		this.declarationOrder = order;
	}

	@Override
	public int getDeclarationOrder() {
		return this.declarationOrder;
	}

	
Set by creator of this advice object if the argument names are known.
This could be for example because they have been explicitly specified in XML,
or in an advice annotation.
Params:
argNames – comma delimited list of arg names/**
	 * Set by creator of this advice object if the argument names are known.
	 * <p>This could be for example because they have been explicitly specified in XML,
	 * or in an advice annotation.
	 * @param argNames comma delimited list of arg names
	 */
	public void setArgumentNames(String argNames) {
		String[] tokens = StringUtils.commaDelimitedListToStringArray(argNames);
		setArgumentNamesFromStringArray(tokens);
	}

	public void setArgumentNamesFromStringArray(String... args) {
		this.argumentNames = new String[args.length];
		for (int i = 0; i < args.length; i++) {
			this.argumentNames[i] = StringUtils.trimWhitespace(args[i]);
			if (!isVariableName(this.argumentNames[i])) {
				throw new IllegalArgumentException(
						"'argumentNames' property of AbstractAspectJAdvice contains an argument name '" +
						this.argumentNames[i] + "' that is not a valid Java identifier");
			}
		}
		if (this.argumentNames != null) {
			if (this.aspectJAdviceMethod.getParameterCount() == this.argumentNames.length + 1) {
				// May need to add implicit join point arg name...
				Class<?> firstArgType = this.aspectJAdviceMethod.getParameterTypes()[0];
				if (firstArgType == JoinPoint.class ||
						firstArgType == ProceedingJoinPoint.class ||
						firstArgType == JoinPoint.StaticPart.class) {
					String[] oldNames = this.argumentNames;
					this.argumentNames = new String[oldNames.length + 1];
					this.argumentNames[0] = "THIS_JOIN_POINT";
					System.arraycopy(oldNames, 0, this.argumentNames, 1, oldNames.length);
				}
			}
		}
	}

	public void setReturningName(String name) {
		throw new UnsupportedOperationException("Only afterReturning advice can be used to bind a return value");
	}

	
We need to hold the returning name at this level for argument binding calculations,
this method allows the afterReturning advice subclass to set the name.
/**
	 * We need to hold the returning name at this level for argument binding calculations,
	 * this method allows the afterReturning advice subclass to set the name.
	 */
	protected void setReturningNameNoCheck(String name) {
		// name could be a variable or a type...
		if (isVariableName(name)) {
			this.returningName = name;
		}
		else {
			// assume a type
			try {
				this.discoveredReturningType = ClassUtils.forName(name, getAspectClassLoader());
			}
			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);
			}
		}
	}

	protected Class<?> getDiscoveredReturningType() {
		return this.discoveredReturningType;
	}

	@Nullable
	protected Type getDiscoveredReturningGenericType() {
		return this.discoveredReturningGenericType;
	}

	public void setThrowingName(String name) {
		throw new UnsupportedOperationException("Only afterThrowing advice can be used to bind a thrown exception");
	}

	
We need to hold the throwing name at this level for argument binding calculations,
this method allows the afterThrowing advice subclass to set the name.
/**
	 * We need to hold the throwing name at this level for argument binding calculations,
	 * this method allows the afterThrowing advice subclass to set the name.
	 */
	protected void setThrowingNameNoCheck(String name) {
		// name could be a variable or a type...
		if (isVariableName(name)) {
			this.throwingName = name;
		}
		else {
			// assume a type
			try {
				this.discoveredThrowingType = ClassUtils.forName(name, getAspectClassLoader());
			}
			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);
			}
		}
	}

	protected Class<?> getDiscoveredThrowingType() {
		return this.discoveredThrowingType;
	}

	private static boolean isVariableName(String name) {
		return AspectJProxyUtils.isVariableName(name);
	}


	
Do as much work as we can as part of the set-up so that argument binding
on subsequent advice invocations can be as fast as possible.
If the first argument is of type JoinPoint or ProceedingJoinPoint then we
pass a JoinPoint in that position (ProceedingJoinPoint for around advice).
If the first argument is of type JoinPoint.StaticPart then we pass a JoinPoint.StaticPart in that position. 
Remaining arguments have to be bound by pointcut evaluation at
a given join point. We will get back a map from argument name to
value. We need to calculate which advice parameter needs to be bound
to which argument name. There are multiple strategies for determining
this binding, which are arranged in a ChainOfResponsibility.
/**
	 * Do as much work as we can as part of the set-up so that argument binding
	 * on subsequent advice invocations can be as fast as possible.
	 * <p>If the first argument is of type JoinPoint or ProceedingJoinPoint then we
	 * pass a JoinPoint in that position (ProceedingJoinPoint for around advice).
	 * <p>If the first argument is of type {@code JoinPoint.StaticPart}
	 * then we pass a {@code JoinPoint.StaticPart} in that position.
	 * <p>Remaining arguments have to be bound by pointcut evaluation at
	 * a given join point. We will get back a map from argument name to
	 * value. We need to calculate which advice parameter needs to be bound
	 * to which argument name. There are multiple strategies for determining
	 * this binding, which are arranged in a ChainOfResponsibility.
	 */
	public final synchronized void calculateArgumentBindings() {
		// The simple case... nothing to bind.
		if (this.argumentsIntrospected || this.parameterTypes.length == 0) {
			return;
		}

		int numUnboundArgs = this.parameterTypes.length;
		Class<?>[] parameterTypes = this.aspectJAdviceMethod.getParameterTypes();
		if (maybeBindJoinPoint(parameterTypes[0]) || maybeBindProceedingJoinPoint(parameterTypes[0]) ||
				maybeBindJoinPointStaticPart(parameterTypes[0])) {
			numUnboundArgs--;
		}

		if (numUnboundArgs > 0) {
			// need to bind arguments by name as returned from the pointcut match
			bindArgumentsByName(numUnboundArgs);
		}

		this.argumentsIntrospected = true;
	}

	private boolean maybeBindJoinPoint(Class<?> candidateParameterType) {
		if (JoinPoint.class == candidateParameterType) {
			this.joinPointArgumentIndex = 0;
			return true;
		}
		else {
			return false;
		}
	}

	private boolean maybeBindProceedingJoinPoint(Class<?> candidateParameterType) {
		if (ProceedingJoinPoint.class == candidateParameterType) {
			if (!supportsProceedingJoinPoint()) {
				throw new IllegalArgumentException("ProceedingJoinPoint is only supported for around advice");
			}
			this.joinPointArgumentIndex = 0;
			return true;
		}
		else {
			return false;
		}
	}

	protected boolean supportsProceedingJoinPoint() {
		return false;
	}

	private boolean maybeBindJoinPointStaticPart(Class<?> candidateParameterType) {
		if (JoinPoint.StaticPart.class == candidateParameterType) {
			this.joinPointStaticPartArgumentIndex = 0;
			return true;
		}
		else {
			return false;
		}
	}

	private void bindArgumentsByName(int numArgumentsExpectingToBind) {
		if (this.argumentNames == null) {
			this.argumentNames = createParameterNameDiscoverer().getParameterNames(this.aspectJAdviceMethod);
		}
		if (this.argumentNames != null) {
			// We have been able to determine the arg names.
			bindExplicitArguments(numArgumentsExpectingToBind);
		}
		else {
			throw new IllegalStateException("Advice method [" + this.aspectJAdviceMethod.getName() + "] " +
					"requires " + numArgumentsExpectingToBind + " arguments to be bound by name, but " +
					"the argument names were not specified and could not be discovered.");
		}
	}

	
Create a ParameterNameDiscoverer to be used for argument binding.
The default implementation creates a DefaultParameterNameDiscoverer and adds a specifically configured AspectJAdviceParameterNameDiscoverer. /**
	 * Create a ParameterNameDiscoverer to be used for argument binding.
	 * <p>The default implementation creates a {@link DefaultParameterNameDiscoverer}
	 * and adds a specifically configured {@link AspectJAdviceParameterNameDiscoverer}.
	 */
	protected ParameterNameDiscoverer createParameterNameDiscoverer() {
		// We need to discover them, or if that fails, guess,
		// and if we can't guess with 100% accuracy, fail.
		DefaultParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
		AspectJAdviceParameterNameDiscoverer adviceParameterNameDiscoverer =
				new AspectJAdviceParameterNameDiscoverer(this.pointcut.getExpression());
		adviceParameterNameDiscoverer.setReturningName(this.returningName);
		adviceParameterNameDiscoverer.setThrowingName(this.throwingName);
		// Last in chain, so if we're called and we fail, that's bad...
		adviceParameterNameDiscoverer.setRaiseExceptions(true);
		discoverer.addDiscoverer(adviceParameterNameDiscoverer);
		return discoverer;
	}

	private void bindExplicitArguments(int numArgumentsLeftToBind) {
		Assert.state(this.argumentNames != null, "No argument names available");
		this.argumentBindings = new HashMap<>();

		int numExpectedArgumentNames = this.aspectJAdviceMethod.getParameterCount();
		if (this.argumentNames.length != numExpectedArgumentNames) {
			throw new IllegalStateException("Expecting to find " + numExpectedArgumentNames +
					" arguments to bind by name in advice, but actually found " +
					this.argumentNames.length + " arguments.");
		}

		// So we match in number...
		int argumentIndexOffset = this.parameterTypes.length - numArgumentsLeftToBind;
		for (int i = argumentIndexOffset; i < this.argumentNames.length; i++) {
			this.argumentBindings.put(this.argumentNames[i], i);
		}

		// Check that returning and throwing were in the argument names list if
		// specified, and find the discovered argument types.
		if (this.returningName != null) {
			if (!this.argumentBindings.containsKey(this.returningName)) {
				throw new IllegalStateException("Returning argument name '" + this.returningName +
						"' was not bound in advice arguments");
			}
			else {
				Integer index = this.argumentBindings.get(this.returningName);
				this.discoveredReturningType = this.aspectJAdviceMethod.getParameterTypes()[index];
				this.discoveredReturningGenericType = this.aspectJAdviceMethod.getGenericParameterTypes()[index];
			}
		}
		if (this.throwingName != null) {
			if (!this.argumentBindings.containsKey(this.throwingName)) {
				throw new IllegalStateException("Throwing argument name '" + this.throwingName +
						"' was not bound in advice arguments");
			}
			else {
				Integer index = this.argumentBindings.get(this.throwingName);
				this.discoveredThrowingType = this.aspectJAdviceMethod.getParameterTypes()[index];
			}
		}

		// configure the pointcut expression accordingly.
		configurePointcutParameters(this.argumentNames, argumentIndexOffset);
	}

	
All parameters from argumentIndexOffset onwards are candidates for
pointcut parameters - but returning and throwing vars are handled differently
and must be removed from the list if present.
/**
	 * All parameters from argumentIndexOffset onwards are candidates for
	 * pointcut parameters - but returning and throwing vars are handled differently
	 * and must be removed from the list if present.
	 */
	private void configurePointcutParameters(String[] argumentNames, int argumentIndexOffset) {
		int numParametersToRemove = argumentIndexOffset;
		if (this.returningName != null) {
			numParametersToRemove++;
		}
		if (this.throwingName != null) {
			numParametersToRemove++;
		}
		String[] pointcutParameterNames = new String[argumentNames.length - numParametersToRemove];
		Class<?>[] pointcutParameterTypes = new Class<?>[pointcutParameterNames.length];
		Class<?>[] methodParameterTypes = this.aspectJAdviceMethod.getParameterTypes();

		int index = 0;
		for (int i = 0; i < argumentNames.length; i++) {
			if (i < argumentIndexOffset) {
				continue;
			}
			if (argumentNames[i].equals(this.returningName) ||
				argumentNames[i].equals(this.throwingName)) {
				continue;
			}
			pointcutParameterNames[index] = argumentNames[i];
			pointcutParameterTypes[index] = methodParameterTypes[i];
			index++;
		}

		this.pointcut.setParameterNames(pointcutParameterNames);
		this.pointcut.setParameterTypes(pointcutParameterTypes);
	}

	
Take the arguments at the method execution join point and output a set of arguments
to the advice method.
Params:
jp – the current JoinPoint
jpMatch – the join point match that matched this execution join point
returnValue – the return value from the method execution (may be null)
ex – the exception thrown by the method execution (may be null)
Returns:
the empty array if there are no arguments/**
	 * Take the arguments at the method execution join point and output a set of arguments
	 * to the advice method.
	 * @param jp the current JoinPoint
	 * @param jpMatch the join point match that matched this execution join point
	 * @param returnValue the return value from the method execution (may be null)
	 * @param ex the exception thrown by the method execution (may be null)
	 * @return the empty array if there are no arguments
	 */
	protected Object[] argBinding(JoinPoint jp, @Nullable JoinPointMatch jpMatch,
			@Nullable Object returnValue, @Nullable Throwable ex) {

		calculateArgumentBindings();

		// AMC start
		Object[] adviceInvocationArgs = new Object[this.parameterTypes.length];
		int numBound = 0;

		if (this.joinPointArgumentIndex != -1) {
			adviceInvocationArgs[this.joinPointArgumentIndex] = jp;
			numBound++;
		}
		else if (this.joinPointStaticPartArgumentIndex != -1) {
			adviceInvocationArgs[this.joinPointStaticPartArgumentIndex] = jp.getStaticPart();
			numBound++;
		}

		if (!CollectionUtils.isEmpty(this.argumentBindings)) {
			// binding from pointcut match
			if (jpMatch != null) {
				PointcutParameter[] parameterBindings = jpMatch.getParameterBindings();
				for (PointcutParameter parameter : parameterBindings) {
					String name = parameter.getName();
					Integer index = this.argumentBindings.get(name);
					adviceInvocationArgs[index] = parameter.getBinding();
					numBound++;
				}
			}
			// binding from returning clause
			if (this.returningName != null) {
				Integer index = this.argumentBindings.get(this.returningName);
				adviceInvocationArgs[index] = returnValue;
				numBound++;
			}
			// binding from thrown exception
			if (this.throwingName != null) {
				Integer index = this.argumentBindings.get(this.throwingName);
				adviceInvocationArgs[index] = ex;
				numBound++;
			}
		}

		if (numBound != this.parameterTypes.length) {
			throw new IllegalStateException("Required to bind " + this.parameterTypes.length +
					" arguments, but only bound " + numBound + " (JoinPointMatch " +
					(jpMatch == null ? "was NOT" : "WAS") + " bound in invocation)");
		}

		return adviceInvocationArgs;
	}


	
Invoke the advice method.
Params:
jpMatch – the JoinPointMatch that matched this execution join point
returnValue – the return value from the method execution (may be null)
ex – the exception thrown by the method execution (may be null)
Throws:
Throwable – in case of invocation failure
Returns:
the invocation result/**
	 * Invoke the advice method.
	 * @param jpMatch the JoinPointMatch that matched this execution join point
	 * @param returnValue the return value from the method execution (may be null)
	 * @param ex the exception thrown by the method execution (may be null)
	 * @return the invocation result
	 * @throws Throwable in case of invocation failure
	 */
	protected Object invokeAdviceMethod(
			@Nullable JoinPointMatch jpMatch, @Nullable Object returnValue, @Nullable Throwable ex)
			throws Throwable {

		return invokeAdviceMethodWithGivenArgs(argBinding(getJoinPoint(), jpMatch, returnValue, ex));
	}

	// As above, but in this case we are given the join point.
	protected Object invokeAdviceMethod(JoinPoint jp, @Nullable JoinPointMatch jpMatch,
			@Nullable Object returnValue, @Nullable Throwable t) throws Throwable {

		return invokeAdviceMethodWithGivenArgs(argBinding(jp, jpMatch, returnValue, t));
	}

	protected Object invokeAdviceMethodWithGivenArgs(Object[] args) throws Throwable {
		Object[] actualArgs = args;
		if (this.aspectJAdviceMethod.getParameterCount() == 0) {
			actualArgs = null;
		}
		try {
			ReflectionUtils.makeAccessible(this.aspectJAdviceMethod);
			return this.aspectJAdviceMethod.invoke(this.aspectInstanceFactory.getAspectInstance(), actualArgs);
		}
		catch (IllegalArgumentException ex) {
			throw new AopInvocationException("Mismatch on arguments to advice method [" +
					this.aspectJAdviceMethod + "]; pointcut expression [" +
					this.pointcut.getPointcutExpression() + "]", ex);
		}
		catch (InvocationTargetException ex) {
			throw ex.getTargetException();
		}
	}

	
Overridden in around advice to return proceeding join point.
/**
	 * Overridden in around advice to return proceeding join point.
	 */
	protected JoinPoint getJoinPoint() {
		return currentJoinPoint();
	}

	
Get the current join point match at the join point we are being dispatched on.
/**
	 * Get the current join point match at the join point we are being dispatched on.
	 */
	@Nullable
	protected JoinPointMatch getJoinPointMatch() {
		MethodInvocation mi = ExposeInvocationInterceptor.currentInvocation();
		if (!(mi instanceof ProxyMethodInvocation)) {
			throw new IllegalStateException("MethodInvocation is not a Spring ProxyMethodInvocation: " + mi);
		}
		return getJoinPointMatch((ProxyMethodInvocation) mi);
	}

	// Note: We can't use JoinPointMatch.getClass().getName() as the key, since
	// Spring AOP does all the matching at a join point, and then all the invocations.
	// Under this scenario, if we just use JoinPointMatch as the key, then
	// 'last man wins' which is not what we want at all.
	// Using the expression is guaranteed to be safe, since 2 identical expressions
	// are guaranteed to bind in exactly the same way.
	@Nullable
	protected JoinPointMatch getJoinPointMatch(ProxyMethodInvocation pmi) {
		String expression = this.pointcut.getExpression();
		return (expression != null ? (JoinPointMatch) pmi.getUserAttribute(expression) : null);
	}


	@Override
	public String toString() {
		return getClass().getName() + ": advice method [" + this.aspectJAdviceMethod + "]; " +
				"aspect name '" + this.aspectName + "'";
	}

	private void readObject(ObjectInputStream inputStream) throws IOException, ClassNotFoundException {
		inputStream.defaultReadObject();
		try {
			this.aspectJAdviceMethod = this.declaringClass.getMethod(this.methodName, this.parameterTypes);
		}
		catch (NoSuchMethodException ex) {
			throw new IllegalStateException("Failed to find advice method on deserialization", ex);
		}
	}


	
MethodMatcher that excludes the specified advice method.
See Also:
buildSafePointcut.buildSafePointcut()/**
	 * MethodMatcher that excludes the specified advice method.
	 * @see AbstractAspectJAdvice#buildSafePointcut()
	 */
	private static class AdviceExcludingMethodMatcher extends StaticMethodMatcher {

		private final Method adviceMethod;

		public AdviceExcludingMethodMatcher(Method adviceMethod) {
			this.adviceMethod = adviceMethod;
		}

		@Override
		public boolean matches(Method method, Class<?> targetClass) {
			return !this.adviceMethod.equals(method);
		}

		@Override
		public boolean equals(@Nullable Object other) {
			if (this == other) {
				return true;
			}
			if (!(other instanceof AdviceExcludingMethodMatcher)) {
				return false;
			}
			AdviceExcludingMethodMatcher otherMm = (AdviceExcludingMethodMatcher) other;
			return this.adviceMethod.equals(otherMm.adviceMethod);
		}

		@Override
		public int hashCode() {
			return this.adviceMethod.hashCode();
		}

		@Override
		public String toString() {
			return getClass().getName() + ": " + this.adviceMethod;
		}
	}

}