Dynamic proxy in proxy Mode

Parse instances in dynamic proxy mode in detail:

1. First, create an interface (there are real methods to be implemented ):

PublicinterfaceSubject {

PublicvoidRequest (); // method to be implemented

}

2. Write a real theme class to implement the subject interface (and implement the method ):

PublicclassRealsubject
ImplementsSubject {

PublicvoidRequest () {// method in the implementation Interface

System.Out. Println ("implementation method of real theme ");

}

}

3. Write a dynamic proxy class to implement the invocationhandler interface:

// The dynamic proxy class should implement the invocationhandler interface (under the java. Lang. Reflect package)

PublicclassProxyhandle
Implements
Invocationhandler {

Object OBJ =
Null;

// Write a binding method and bind different interfaces for proxy

PublicObject BIND (Object OBJ ){

This. OBJ = OBJ;

// The return value of this method is an object.

// Proxy has a method newproxyinstace (); there are three parameters: First: The Class Loader that represents the real class instance of the proxy

// The second parameter indicates the interface implemented by the real class to be proxy

// The third is the proxy class itself.

ReturnProxy.Newproxyinstance(Obj. getclass (). getclassloader (), obj. getclass (). getinterfaces (),
This);

}

// Invocationhandler interface method invoke ()

// The method in invoke () indicates the method in the implementation interface of the real class.

PublicObject
Invoke (Object proxy, method, object [] ARGs)

ThrowsThrowable {

// Call the invoke () method in the parameter method, which has two parameters

// The first parameter indicates the real class of the proxy.

// The second parameter indicates the input parameter object array.

System.Out. Println ("proxy previous task ~~~ ");

Object o = method. Invoke (This. OBJ, argS );

System.Out. Println ("task after proxy ~~ ");

ReturnO; // return the implementation class of a proxy Interface

}

}

4. Test the dynamic proxy class: testproxy
Public class testproxy {
Public static void main (string ARGs []) {
Proxyhandle pH = new proxyhandle (); // get the proxy class Object
// Real subject object bound to the proxy
Subject sub = (subject) Ph. BIND (New realsubject (); // bind the real subject to the proxy
Sub. Request (); // call the request of a real object (a method in the implementation Interface)
// At this time, the invock () method in the proxy class will be automatically called to complete the proxy process
}
// If the proxy has different real classes, directly change the parameters in the BIND () method, and pass in the real class you want to proxy to OK.
// This enables dynamic proxy.
}
In this way, a dynamic proxy instance is completed in four steps, and each step is explained in the code.