java动态代理

User.java

public class User {

	private String name;
	private int age;
	private int id;
	
	

	@Override
	public String toString() {
		return "{"+name+" , "+age+" , "+id+"}";
	}

	public User(String name, int age, int id) {
		super();
		this.name = name;
		this.age = age;
		this.id = id;
	}

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

}

 

UserManager.java

public interface UserManager {

	public void addUser(User user);
	
	public void delUser(User user);
	
	public void queryUserByID(int id);
}

UserManagerImpl.java

public class UserManagerImpl implements UserManager {

	@Override
	public void addUser(User user) {
		System.out.println("UserManagerImpl.addUser--->>name="+user.getName());
	}

	@Override
	public void delUser(User user) {
		System.out.println("UserManagerImpl.delUser--->>name="+user.getName());
	}

	@Override
	public void queryUserByID(int id) {
		System.out.println("UserManagerImpl.id--->>id="+id);
	}
}

ProxyTest.java

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class ProxyTest implements InvocationHandler {

	Object target;
	
	public Object proxyObject(Object target) {
		this.target = target;
		return Proxy.newProxyInstance(target.getClass().getClassLoader(), target
				.getClass().getInterfaces(), this);
	}
	
	@Override
	public Object invoke(Object proxy, Method method, Object[] args)
			throws Throwable {
		Object ret = null;
		System.out.println(method.getName());
		for(int i=0;i<args.length;i++){
			System.out.println(args[i]);
		}
		//执行方法并返回方法的返回值没有则返回null
		ret = method.invoke(target, args);
		return ret;
	}
}

 

Client.java

public class Client {
	public static void main(String[] args) {
		User user = new User("小明", 22, 1);
		UserManager userManager = (UserManager) new ProxyTest()
				.proxyObject(new UserManagerImpl());
		userManager.delUser(user);
	}
}

执行结果：

delUser
{小明 , 22 , 1}
UserManagerImpl.delUser--->>name=小明