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This article mainly explains "the usage of ProxyFactory in SpringFramework". The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn "the usage of ProxyFactory in SpringFramework".

The Spring version is 5.0.4.release.

ProxyFactory plays an important role in Springaop and is used to create proxies indirectly. As shown in List-1 below, we create proxies for ServiceImpl.

List-1

Public interface IService {String hello ();} public class ServiceImpl implements IService {@ Override public String hello () {System.out.println ("hello method of service"); return "Hello";}} import org.springframework.aop.MethodBeforeAdvice;import java.lang.reflect.Method Public class BeforeAdvice implements MethodBeforeAdvice {@ Override public void before (Method method, Object [] args, Object target) throws Throwable {System.out.println ("before method of beforeAdvice");}} import org.springframework.aop.AfterReturningAdvice;import java.lang.reflect.Method;public class AfterAdvice implements AfterReturningAdvice {@ Override public void afterReturning (Object returnValue, Method method, Object [] args, Object target) throws Throwable {System.out.println ("afterReturning method of AfterAdvice");} import org.junit.Test Import org.springframework.aop.framework.ProxyFactory;public class AopTest {@ Test public void test () {ProxyFactory proxyFactory = new ProxyFactory (); proxyFactory.setInterfaces (IService.class); proxyFactory.setTarget (new ServiceImpl ()); proxyFactory.addAdvice (new BeforeAdvice ()); proxyFactory.addAdvice (new AfterAdvice ()); IService proxy = (IService) proxyFactory.getProxy (); String result = proxy.hello () System.out.println (result);}}

The running result is as follows: List-2

List-2

BeforeAdvice's before method service's hello method AfterAdvice's afterReturning method Hello

When proxyFactory.addAdvice (new BeforeAdvice ()), the Advice is converted to Advisor, and finally the addAdvisor method is called.

When we call ProxyFactory's getProxy, we first call createAopProxy ()-> getAopProxyFactory (). CreateAopProxy (this), AopProxyFactory is what DefaultAopProxyFactory-- talked about in another article. This is passed in the createAopProxy method, and ProxyFactory implements AdvisedSupport, so the targetSource, advice and so on set in ProxyFactory are passed to DefaultAopProxyFactory and then passed to JdkDynamicAopProxy when createAopProxy.

Finally, getProxy calls the getProxy method of JdkDynamicAopProxy, as shown in the following List-3. In the method of Proxy.newProxyInstance, the last InvocationHandler is this--JdkDynamicAopProxy that implements InvocationHandler, so when we call the method of the target class, we call the invoke method of JdkDynamicAopProxy.

List-3

Public Object getProxy (@ Nullable ClassLoader classLoader) {if (logger.isDebugEnabled ()) {logger.debug ("Creating JDK dynamic proxy: target source is" + this.advised.getTargetSource ());} Class [] proxiedInterfaces = AopProxyUtils.completeProxiedInterfaces (this.advised, true); findDefinedEqualsAndHashCodeMethods (proxiedInterfaces); return Proxy.newProxyInstance (classLoader, proxiedInterfaces, this);}

This leads to the question of how the interceptor chain is constructed in JdkDynamicAopProxy's invoke method.

Thank you for your reading, the above is the content of "the usage of ProxyFactory in SpringFramework". After the study of this article, I believe you have a deeper understanding of the use of ProxyFactory in SpringFramework, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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