org.springframework.aop.framework.JdkDynamicAopProxy Maven / Gradle / Ivy
/*
* 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.framework;
import java.io.Serializable;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.List;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.aop.AopInvocationException;
import org.springframework.aop.RawTargetAccess;
import org.springframework.aop.TargetSource;
import org.springframework.aop.support.AopUtils;
import org.springframework.core.DecoratingProxy;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* JDK-based {@link AopProxy} implementation for the Spring AOP framework,
* based on JDK {@link java.lang.reflect.Proxy dynamic proxies}.
*
* Creates a dynamic proxy, implementing the interfaces exposed by
* the AopProxy. Dynamic proxies cannot be used to proxy methods
* defined in classes, rather than interfaces.
*
*
Objects of this type should be obtained through proxy factories,
* configured by an {@link AdvisedSupport} class. This class is internal
* to Spring's AOP framework and need not be used directly by client code.
*
*
Proxies created using this class will be thread-safe if the
* underlying (target) class is thread-safe.
*
*
Proxies are serializable so long as all Advisors (including Advices
* and Pointcuts) and the TargetSource are serializable.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @author Rob Harrop
* @author Dave Syer
* @author Sergey Tsypanov
* @see java.lang.reflect.Proxy
* @see AdvisedSupport
* @see ProxyFactory
*/
final class JdkDynamicAopProxy implements AopProxy, InvocationHandler, Serializable {
/** use serialVersionUID from Spring 1.2 for interoperability. */
private static final long serialVersionUID = 5531744639992436476L;
/*
* NOTE: We could avoid the code duplication between this class and the CGLIB
* proxies by refactoring "invoke" into a template method. However, this approach
* adds at least 10% performance overhead versus a copy-paste solution, so we sacrifice
* elegance for performance. (We have a good test suite to ensure that the different
* proxies behave the same :-)
* This way, we can also more easily take advantage of minor optimizations in each class.
*/
/** We use a static Log to avoid serialization issues. */
private static final Log logger = LogFactory.getLog(JdkDynamicAopProxy.class);
/** Config used to configure this proxy. */
private final AdvisedSupport advised;
private final Class[] proxiedInterfaces;
/**
* Is the {@link #equals} method defined on the proxied interfaces?
*/
private boolean equalsDefined;
/**
* Is the {@link #hashCode} method defined on the proxied interfaces?
*/
private boolean hashCodeDefined;
/**
* Construct a new JdkDynamicAopProxy for the given AOP configuration.
* @param config the AOP configuration as AdvisedSupport object
* @throws AopConfigException if the config is invalid. We try to throw an informative
* exception in this case, rather than let a mysterious failure happen later.
*/
public JdkDynamicAopProxy(AdvisedSupport config) throws AopConfigException {
Assert.notNull(config, "AdvisedSupport must not be null");
if (config.getAdvisorCount() == 0 && config.getTargetSource() == AdvisedSupport.EMPTY_TARGET_SOURCE) {
throw new AopConfigException("No advisors and no TargetSource specified");
}
this.advised = config;
this.proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces(this.advised, true);
findDefinedEqualsAndHashCodeMethods(this.proxiedInterfaces);
}
@Override
public Object getProxy() {
return getProxy(ClassUtils.getDefaultClassLoader());
}
@Override
public Object getProxy(@Nullable ClassLoader classLoader) {
if (logger.isTraceEnabled()) {
logger.trace("Creating JDK dynamic proxy: " + this.advised.getTargetSource());
}
return Proxy.newProxyInstance(classLoader, this.proxiedInterfaces, this);
}
/**
* Finds any {@link #equals} or {@link #hashCode} method that may be defined
* on the supplied set of interfaces.
* @param proxiedInterfaces the interfaces to introspect
*/
private void findDefinedEqualsAndHashCodeMethods(Class[] proxiedInterfaces) {
for (Class proxiedInterface : proxiedInterfaces) {
Method[] methods = proxiedInterface.getDeclaredMethods();
for (Method method : methods) {
if (AopUtils.isEqualsMethod(method)) {
this.equalsDefined = true;
}
if (AopUtils.isHashCodeMethod(method)) {
this.hashCodeDefined = true;
}
if (this.equalsDefined && this.hashCodeDefined) {
return;
}
}
}
}
/**
* Implementation of {@code InvocationHandler.invoke}.
*
Callers will see exactly the exception thrown by the target,
* unless a hook method throws an exception.
*/
@Override
@Nullable
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Object oldProxy = null;
boolean setProxyContext = false;
TargetSource targetSource = this.advised.targetSource;
Object target = null;
try {
if (!this.equalsDefined && AopUtils.isEqualsMethod(method)) {
// The target does not implement the equals(Object) method itself.
return equals(args[0]);
}
else if (!this.hashCodeDefined && AopUtils.isHashCodeMethod(method)) {
// The target does not implement the hashCode() method itself.
return hashCode();
}
else if (method.getDeclaringClass() == DecoratingProxy.class) {
// There is only getDecoratedClass() declared -> dispatch to proxy config.
return AopProxyUtils.ultimateTargetClass(this.advised);
}
else if (!this.advised.opaque && method.getDeclaringClass().isInterface() &&
method.getDeclaringClass().isAssignableFrom(Advised.class)) {
// Service invocations on ProxyConfig with the proxy config...
return AopUtils.invokeJoinpointUsingReflection(this.advised, method, args);
}
Object retVal;
if (this.advised.exposeProxy) {
// Make invocation available if necessary.
oldProxy = AopContext.setCurrentProxy(proxy);
setProxyContext = true;
}
// Get as late as possible to minimize the time we "own" the target,
// in case it comes from a pool.
target = targetSource.getTarget();
Class targetClass = (target != null ? target.getClass() : null);
// Get the interception chain for this method.
List