Java Dynamic Agent

First we define an interface

 Public Interface Sayservice {    publicvoid  Say ();}

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Then implement this interface

 Public class Implements Sayservice {    @Override    publicvoid  say () {        System.out.println ("I Want to go shoping. " );    }}

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Define a dynamic proxy class, each dynamic proxy class must implement Invocationhandler this interface

ImportJava.lang.reflect.InvocationHandler;ImportJava.lang.reflect.Method; Public classDynamicproxyImplementsInvocationhandler {//the real object we're going to be acting for    PrivateObject object;  PublicDynamicproxy (Object object) { This. Object =object; } @Override PublicObject Invoke (Object proxy, Method method, object[] args)throwsthrowable {System.out.println ("Before Go shoping"); //when a contemporary object invokes a method of a real object, it automatically jumps to the Invoke method of the handler object associated with the proxy object .Method.invoke (object, args); System.out.println ("After Go shoping"); return NULL; }}

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Defining test methods

 Public classTestproxy { Public Static voidMain (string[] args) {//the object to be proxiedSayservice Sayimpl =NewSayimpl (); //to proxy which object, it is necessary to transfer the object in, and finally through its real object to invoke the method'sInvocationhandler handler =NewDynamicproxy (Sayimpl); //proxy.newproxyinstance--Creating a proxy object//Handler.getclass (). getClassLoader ()---Load proxy object//Sayimpl.getclass (). Getinterfaces ()--the interface provided for the proxy object is the interface implemented by the real object, which means that we are going to proxy the real object, so that we can invoke the method in the interface//Invocationhandler This object on the handler-associationSayservice Sayservice =(Sayservice) proxy.newproxyinstance (Handler.getclass (). getClassLoader (), Sayimpl.getclass (). GETINTERFAC        ES (), handler);            Sayservice.say (); }}

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Log for console printing

Before Go shoping
I want to go shoping.
After Go shoping

Java Dynamic Agent