Java design mode--proxy mode

Proxy mode proxies: to provide a proxy for other objects and to control access to the object, like the relationship between the broker and the star, the broker is the star's proxy class. The simple thing is to do the processing before and after the method call, AOP idea, the advantage is not to change the original class method on the basis of dynamic add other methods.

3 Roles for proxy mode

1. Abstract role 2. Real role

3. Proxy roles

1. Static Proxy

The proxy class invokes the method of the proxy class.

2. Dynamic Agent---More commonly used

 Public Interface people {            void  eat ();    }

 Public class Implements people {    publicvoid  eat () {        System.out.println ("eat");}    }

Proxy class---Need to implement Invocationhandler interface

 Public classPorxyhandlerImplementsInvocationhandler {People people=NULL;  PublicPorxyhandler (People people) { This. People =people; }     Publicobject Invoke (Object proxy, Method method, object[] args)throwsThrowable { This. before ();        Method.invoke (people, args);  This. After (); return NULL; }        Private voidbefore () {System.out.println (Wash); }        Private voidAfter () {System.out.println ("Wash the dishes"); }}

 Public class Client {        publicstaticvoid  main (string[] args) {        new Class[]{people.  Classnew Proxyhandler (new  Zhangsan ()));        People.eat ();            }}

Java design mode--proxy mode