Java的动态代理.doc

Java的动态代理2005年03月21日jdk1.3后提供了对动态代理技术的支持。间接支持了AOP.该代理的实现要求被代理的类必须由接口实现
而CGLIB工具包提供了对非接口实现类的代理功能

jdk1.3后提供了对动态代理技术的支持。间接支持了AOP
代理类：packagecom.gever.jcw.dproxy;
importjava.lang.reflect.InvocationHandler;importjava.lang.reflect.Method;importjava.lang.reflect.Proxy;
publicclassAOPHandlerimplementsInvocationHandler{privateObjectoriginalObject;privateAOPHandler(Objectobj){this.originalObject=obj;}publicstaticObjectbind(Objectobj){returnProxy.newProxyInstance(obj.getClass().getClassLoader(),obj.getClass().getInterfaces(),newAOPHandler(obj));}
publicObjectinvoke(Objectproxy,Methodarg1,Object[]arg2)throwsThrowable{Objectresult=null;if(arg1.getName().equals("doWork")){System.out.println("Iampreparingmywork!");result=arg1.invoke(originalObject,arg2);}else{System.out.println("Iampreparingtheotherthing!");result=arg1.invoke(originalObject,arg2);}returnresult;}}
接口类：
packagecom.gever.jcw.dproxy;publicinterfaceWorker{publicvoiddoWork();publicvoidgetSalary();}
实现类：
packagecom.gever.jcw.dproxy;publicclassWorkerImplimplementsWorker{publicWorkerImpl(){System.out.println("Iamgettinginstance");}publicvoiddoWork(){System.out.print("Iamworking!");}publicvoidgetSalary(){System.out.print("IamgettingmySalary!");}}
测试类
publicclassManager{publicManager(){}
publicstaticvoidmain(String[]args){Workerworker=(Worker)AOPHandler.bind(newWorkerImpl());worker.doWork();worker.getSalary();}}
以上代码在JDK1.4.2下运行结果为：
IamgettinginstanceIampreparemywork!Iamworking!Iampreparetheotherthing!IamgettingmySalary!

利用CGLIB工具包，可以对非接口实现类的动态代理
代理类：
packagecom.gever.jcw.dproxy;
importjava.lang.reflect.Method;
importnet.sf.cglib.proxy.Enhancer;importnet.sf.cglib.proxy.MethodInterceptor;importnet.sf.cglib.proxy.MethodProxy;
publicclassAOPAnotherimplementsMethodInterceptor{privateEnhancerenhancer=newEnhancer();publicAOPAnother(){super();}
/*(non-Javadoc)*@seenet.sf.cglib.proxy.MethodInterceptor#intercept(java.lang.Object,java.lang.reflect.Method,java.lang.Object[],net.sf.cglib.proxy.MethodProxy)*/publicObjectintercept(Objec