【RPC通信框架】基于接口的客户端实现动态代理原理

一、接口的代理类实现

1、客户端接口代理类

package com.spring.sxf.study.springtradedao.reflector.demo;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.springframework.aop.framework.ProxyFactory;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;

/**
 *
 * @date 7:44 PM 2019/12/26
 */
public class PayFactory implements FactoryBean<Object>, InitializingBean {

    /**
     * 要代理的远程接口
     */
    private Class<?> face;

    /**
     * 对接口生成的代理对象
     */
    private Object proxy;


    public void setFace(Class<?> cls) {
        this.face = cls;
    }

    @Override
    public Object getObject() throws Exception {
        return proxy;
    }

    @Override
    public Class<?> getObjectType() {
        return face;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        //基于spring的aop代理机制，生成代理对象
        proxy = new ProxyFactory(face, new RemoteHandler()).getProxy();
    }

}

/**
 * 处理客户端请求的实现
 */
class RemoteHandler implements MethodInterceptor {

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        //可以在该方法内实现服务发现，服务路由

        String name = invocation.getMethod().getName();
        Object[] arg=invocation.getArguments();

        System.out.println("methodName=>" + name);

        if("pay".equals(name)){

            Req req= (Req) arg[0];
            System.out.println("请求信息如下:["+req.getName()+"]["+req.getAge()+"]");

            PayRes payRes=new PayRes();
            payRes.setMsg("success");
            payRes.setTag(true);
            return payRes;
        }else{
            return "我是中国人";
        }
    }
}

2、远程接口信息

package com.spring.sxf.study.springtradedao.reflector.demo;

/**
 *
 * @date 7:40 PM 2019/12/26
 */
public interface PayService {

    PayRes pay(Req req);

    String refund(String refundNo);

}




package com.spring.sxf.study.springtradedao.reflector.demo;

/**
 * @date 7:41 PM 2019/12/26
 */
public class Req {

    private String name;
    private long age;

    public String getName() {
        return name;
    }

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

    public long getAge() {
        return age;
    }

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



package com.spring.sxf.study.springtradedao.reflector.demo;

/**
 * @date 7:41 PM 2019/12/26
 */
public class PayRes {

    private boolean tag;
    private String msg;

    public boolean isTag() {
        return tag;
    }

    public void setTag(boolean tag) {
        this.tag = tag;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

3、测试

package com.spring.sxf.study.springtradedao.reflector.Test;

import com.spring.sxf.study.springtradedao.reflector.demo.PayFactory;
import com.spring.sxf.study.springtradedao.reflector.demo.PayRes;
import com.spring.sxf.study.springtradedao.reflector.demo.PayService;
import com.spring.sxf.study.springtradedao.reflector.demo.Req;

import org.springframework.aop.support.AopUtils;
import org.springframework.core.io.DefaultResourceLoader;

import java.lang.reflect.Method;

/**
 * @date 8:09 PM 2019/12/26
 */
public class Test {

    public static void main(String[] args) throws Exception {
        testProxy();
//        testReflector();

    }



    /**
     * methodName=>pay
     * 请求信息如下:[sxf][100]
     * 响应结果为:success
     * methodName=>refund
     * result=>我是中国人
     * @throws Exception
     */
    public static void testProxy() throws Exception {
        PayFactory payFactory=new PayFactory();
        payFactory.setFace(PayService.class);
        payFactory.afterPropertiesSet();
        PayService payService= (PayService) payFactory.getObject();

        Req req=new Req();
        req.setName("sxf");
        req.setAge(100);
        PayRes payRes=payService.pay(req);
        System.out.println("响应结果为:"+payRes.getMsg());

        String result=payService.refund("122333");
        System.out.println("result=>"+result);
    }


    /**
     * 当前对象为代理对象
     * 当前代理对象的代理的类为=>class com.sun.proxy.$Proxy0
     * 目标代理类为=>interface com.spring.sxf.study.springtradedao.reflector.demo.PayService
     * @throws Exception
     */
    public static  void testReflector() throws Exception {
        PayFactory payFactory=new PayFactory();
        payFactory.setFace(PayService.class);
        payFactory.afterPropertiesSet();
        PayService payService= (PayService) payFactory.getObject();

        if(AopUtils.isAopProxy(payService)){
            System.out.println("当前对象为代理对象");
            Class<?> cls=AopUtils.getTargetClass(payService);
            System.out.println("当前代理对象的代理的类为=>"+cls);

            Class target=payFactory.getObjectType();
            System.out.println("目标代理类为=>"+target);

            Method method=null;
            Method[] methods= target.getDeclaredMethods();
            for(Method method1:methods){
                if(method1.getName().equals("pay")){
                    method=method1;
                }
            }


            Req req=new Req();
            req.setName("sxf");
            req.setAge(100);

            PayRes o = (PayRes) method.invoke(payService,req);

            System.out.println("执行结果=>"+o.getMsg());





        }else{
            System.out.println("class=>"+payService.getClass());
        }




    }


}