Spring (10) implements AOP technology through dynamic proxies (JDK proxies) and Cglib

All interface methods for the target object

Package Test.spring.service;public interface Personservice {public String getpersonname (Integer id);p ublic void Save ( String name);}

Target Object

Package Test.spring.service.impl;import test.spring.service.personservice;//proxy object Implementation target object all interfaces public class Personservicebean implements Personservice {private String user = Null;public Personservicebean () {}public Personservicebean (String user) {super (); this.user = user;} Public String GetUser () {return user;} public void SetUser (String user) {this.user = user;} @Overridepublic String getpersonname (Integer ID) {//TODO auto-generated method Stubreturn "Getpersonname";} @Overridepublic void Save (String name) {//TODO auto-generated method StubSystem.out.println ("Save ()->>" + name);}}

The

proxy object, which intercepts all business methods, determines whether the user has permissions based on whether or not it is null, allows execution of a business method with permission, and does not execute without permission.

package test.spring.aop;import Java.lang.reflect.invocationhandler;import Java.lang.reflect.method;import Java.lang.reflect.proxy;import Test.spring.service.impl.personservicebean;public Class Proxyfactory implements Invocationhandler {Private object proxyobject;//Create proxy object instance public object Createproxyintance (Object proxyobject) {this.proxyobject = proxyobject;/* * First parameter: Class loader * Second parameter: Gets the interface of the target object, and proxy will implement all of these interfaces * The third parameter: A callback function that determines which class of interface is implemented */return Pro Xy.newproxyinstance (This.proxyObject.getClass (). getClassLoader (), This.proxyObject.getClass (). Getinterfaces (), this);} /* First parameter: Proxy object * Second parameter: Blocked method * Third parameter: Method input parameter */@Overridepublic object Invoke (Object proxy, method, object[] Ar GS) throws Throwable {Personservicebean Personservicebean = (personservicebean) this.proxyobject;object target = null;// User is not NULL description has permission if (Personservicebean.getuser ()! = NULL) {//Delegate call to proxy object method to target object = Method.invoke (Proxyobject, args);} return target;}} 

Permission test

Package Test.spring.junit;import static Org.junit.assert.*;import Org.junit.test;import Test.spring.aop.proxyfactory;import Test.spring.service.personservice;import Test.spring.service.impl.personservicebean;public class Aoptest {@Testpublic void Test () {Proxyfactory pfactory = new Proxyfactory ();//Personservice pservice= (Personservice)//Pfactory.createproxyintance (New Personservicebean ("KKK" ), or//change to the default function Pservice.save ("PPP") will not execute, because the preceding user=null, equivalent to no permission to execute personservice pservice = (personservice) Pfactory.createproxyintance (New Personservicebean ());p Service.save ("PPP");}

The above applies to the target object implementation of the interface, if the target object does not have an interface, will choose to use Cglib

First Import Cglib-nodep-2.1_3.jar

Package test.spring.service.impl;//proxy object implements target object all interfaces public class PersonServiceBean2 {private String user = Null;public PersonServiceBean2 () {}public PersonServiceBean2 (String user) {super (); this.user = user;} Public String GetUser () {return user;} public void SetUser (String user) {this.user = user;} public void Save (String name) {//TODO auto-generated method StubSystem.out.println ("Save ()->>" + name);}}

Package Test.spring.aop;import Java.lang.reflect.method;import Test.spring.service.impl.personservicebean2;import Net.sf.cglib.proxy.callback;import Net.sf.cglib.proxy.enhancer;import Net.sf.cglib.proxy.MethodInterceptor; Import net.sf.cglib.proxy.methodproxy;//target object does not have interface public class Cglibproxyfactory implements Methodinterceptor {private Object proxyobject;//Create proxy object instance public object Createproxyintance (object proxyobject) {this.proxyobject = Proxyobject; Enhancer enhancer = new enhancer ();/* need to set the parent class, which is the target class. The object to be created inherits the target class, overwriting all non-final methods in the target class, and then adding some of its own code */enhancer.setsuperclass (This.proxyObject.getClass ()) in the overridden code; Enhancer.setcallback ((Callback) this); return Enhancer.create ();} /* First parameter: The proxy object itself * The second parameter: the method being intercepted * The third parameter: The parameter of the method * The fourth parameter: the proxy object of the method *///the business method of the contemporary objects call this method when the callback is @overridepublic object inte Rcept (Object Proxy, method, object[] Args,methodproxy methodproxy) throws Throwable {PersonServiceBean2 Personservicebean = (PersonServiceBean2) this.proxyobject;object target = null;//useR is not NULL description has permission if (Personservicebean.getuser ()! = NULL) {//Delegate call to method to target object = Methodproxy.invoke (Proxyobject, args);} return target;}}

Package Test.spring.junit;import static Org.junit.assert.*;import Org.junit.test;import Test.spring.aop.cglibproxyfactory;import Test.spring.aop.proxyfactory;import Test.spring.service.PersonService; Import Test.spring.service.impl.personservicebean;import Test.spring.service.impl.personservicebean2;public class AOPTest2 {@Testpublic void Test () {cglibproxyfactory pfactory = new Cglibproxyfactory ();// At this point Personservicebean has no interface PersonServiceBean2 Pservice = (PersonServiceBean2) pfactory.createproxyintance (new PersonServiceBean2 ("KKK"));p Service.save ("PPP");}}

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Spring (10) implements AOP technology through dynamic proxies (JDK proxies) and Cglib