Spring's AOP (ii)----JDK Dynamic proxy __jdk dynamic proxy

The JDK dynamic proxy is introduced at 1.3, and its underlying need relies on a tool class Java.lang.reflect.Proxy and an interface Java.lang.reflect.InvocationHandler

JDK Dynamic proxy must be agent based on interface

code example:
Jdkproxyutils.java

Package com.my.jdkproxy;

Import Java.lang.reflect.InvocationHandler;
Import Java.lang.reflect.Method;
Import Java.lang.reflect.Proxy;

Create JDK dynamic Proxy (tool Class) Public
class Jdkproxyutils implements Invocationhandler {

    //Proxy target object
    private object T for target object Arget; 

    Public jdkproxyutils (Object target) {
        this.target = target;
    }

    The target object method is invoked by invoke @Override public object
    Invoke (Object proxy, methods method, object[] args)
            throws Throwable {
        System.out.println ("Perform JDK agent enhancements ...) ");
        Return Method.invoke (target, args); Invoke target object Method
    }//

    create proxy for target object
    Createproxy () {
        //Loader object class loader
        //interfaces The target object implements
        the interface//h  callback object and requires Invocationhandler to execute the target object method return

        proxy.newproxyinstance (Target.getclass (). getClassLoader (), Target.getclass (). Getinterfaces (), this);

    }

Userdao.java

Package com.my.jdkproxy;

User Action Interface Public
interface Userdao {public
    void Save ();
    public void Update ();
    public void Delete ();

}

Userdaoimpl.java

Package com.my.jdkproxy;

User Action implementation class public classes
Userdaoimpl implements Userdao {

    @Override public
    Void Save () {
        SYSTEM.OUT.PRINTLN (save user ...) ");
    }

    @Override public
    Void Update () {
        System.out.println ("Update user ..."). ");
    }

    @Override public
    Void Delete () {
        System.out.println ("Delete user ...). ");
    }

}

Test.java

Package com.my.jdkproxy;


public class Test {

    //no agent Programming
    @org. Junit.test public
    void Demo1 () {
        System.out.println ("no agent Programming");
        Business Object
        Userdao Userdao = new Userdaoimpl ();

        Userdao.save ();
        Userdao.update ();
        Userdao.delete ();

        System.out.println ("----------------");
    }

    Apply JDK dynamic proxy
    @org. Junit.test public
    void Demo2 () {
        System.out.println ();
        SYSTEM.OUT.PRINTLN ("Application JDK dynamic Proxy");
        Target object
        Userdao Userdao = new Userdaoimpl ();

        Create JDK dynamic proxy for target object
        jdkproxyutils jdkproxyutils = new Jdkproxyutils (Userdao);//Incoming target object
        Userdao proxy = (Userdao ) Jdkproxyutils.createproxy (); Agent 

        //Invoke proxy object method must be created based on interface
        Proxy.save ();//Execute Invocationhandler Invoke method
        proxy.update ();
        Proxy.delete ();

    }

Run Result: