JDK提供的动态代理

JDK提供的动态代理

提供接口和实现类

package cn.chen.proxy.jdk;

public interface UserMgr {

    void addUser();

}

package cn.chen.proxy.jdk;

public class UserMgrImpl implements UserMgr {
    @Override
    public void addUser() {
        System.out.println("1.插入记录到User表");
        System.out.println("2.做日志在另外一张表");
    }
}

对代理类进行处理

package cn.chen.proxy.jdk;

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

public class TransProxyByJDK implements InvocationHandler{

    private Object target;

    public TransProxyByJDK(Object target) {
        this.target = target;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("transacation start");
        method.invoke(target, args);
        System.out.println("transacation commit");
        return null;
    }
}

测试

package cn.chen.proxy.jdk;

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

public class Client {

    public static void main(String[] args) throws Exception {
        UserMgr userMgr = new UserMgrImpl();
        InvocationHandler h = new TransProxyByJDK(userMgr);
        UserMgr u = (UserMgr) Proxy.newProxyInstance(userMgr.getClass().getClassLoader() ,new Class[]{UserMgr.class}, h);
        u.addUser();
    }

}


transacation start
1.插入记录到User表
2.做日志在另外一张表
transacation commit

Process finished with exit code 0

JDK的动态代理中代理类必须实现接口，cglib实现动态代理则不用:cglib实现动态代理