Java 动态代理

SmsService

package org.example;

public interface SmsService {
    String send(String message);
}

SmsServiceImpl

package org.example;

public class SmsServiceImpl implements SmsService {
    @Override
    public String send(String message) {
        System.out.println("发送信息" + message);
        return "已经发送信息： " + message;
    }
}

DynamicInvocationHandler —> 实际得代理类

package org.example;

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

public class DynamicInvocationHandler  implements InvocationHandler {
    private final Object target;
    public DynamicInvocationHandler(Object target) {
        this.target = target;
    }
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("before method " + method.getName());
        Object result = method.invoke(target, args);
        System.out.println("after method " + method.getName());
        return result;
    }
}

ProxyFactory

package org.example;

import java.lang.reflect.Proxy;

public class ProxyFactory {
    public static Object getProxy(Object target) {
        return Proxy.newProxyInstance(
                target.getClass().getClassLoader(), // 目标类的类加载器
                target.getClass().getInterfaces(),  // 代理需要实现的接口，可指定多个
                new DynamicInvocationHandler(target)   // 代理对象对应的自定义 InvocationHandler
        );

    }
}

Main

package org.example;

public class Main {
    public static void main(String[] args) {
        SmsService smsService = (SmsService) ProxyFactory.getProxy(new SmsServiceImpl());
        smsService.send("hello");
    }
}