手写DubboRPC

流程图

ClientBootstrap

package com.netty.dubboRPC.customer;

import com.netty.dubboRPC.netty.NettyClient;
import com.netty.dubboRPC.publicInterface.HelloService;

public class ClientBootstrap {
    //协议头
    public static final String providerName = "HelloService#hello#";

    public static void main(String[] args) throws InterruptedException {
        //创建一个消费者
        NettyClient customer = new NettyClient();
        //创建代理对象
        HelloService service = (HelloService) customer.getBean(HelloService.class, providerName);
        for (; ; ) {
            Thread.sleep(2 * 1000);
            //通过代理对象调用服务提供者的方法
            String res = service.hello("你好，dubbo");
            System.out.println("调用结果 res:" + res);
        }
    }
}

NettyClient

package com.netty.dubboRPC.netty;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

import java.lang.reflect.Proxy;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class NettyClient {
    //线程池
    private static ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    private static NettyClientHandler client;

    //使用代理模式，获取代理对象
    public Object getBean(final Class<?> serviceClass, final String providerName) {

        return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class<?>[]{serviceClass}, (proxy, method, args) -> {
            //此段{}中的代码，客户端每调用一次hello，就会进入该代码
            if (client == null) {
                initClient();
            }
            //设置发给服务端信息,providerName协议头，args[0]是客户端调用api hello(?)中的参数
            client.setPara(providerName + args[0]);
            return executor.submit(client).get();
        });
    }

    //初始化客户端
    private static void initClient() throws InterruptedException {
        client = new NettyClientHandler();
        //创建EventLoopGroup
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY, true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline p = ch.pipeline();
                            p.addLast(new StringDecoder())
                                    .addLast(new StringEncoder())
                                    .addLast(client);
                        }
                    });

            b.connect("127.0.0.1", 7000).sync();
            //ChannelFuture f = b.connect("127.0.0.1", 7000).sync();
            //f.channel().closeFuture().sync();
        } finally {
            //group.shutdownGracefully();
        }
    }
}

NettyClientHandler

package com.netty.dubboRPC.netty;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.CharsetUtil;

import javax.swing.plaf.IconUIResource;
import java.util.concurrent.Callable;

public class NettyClientHandler extends ChannelInboundHandlerAdapter implements Callable {
    private ChannelHandlerContext context;
    private String result;//返回结果
    private String para;//传入参数

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        context = ctx;
    }

    @Override
    public synchronized void channelRead(ChannelHandlerContext ctx, Object msg) {
        result = msg.toString();
        notify();
    }

    @Override
    public synchronized Object call() throws Exception {
        context.writeAndFlush(para);
        //context.writeAndFlush(Unpooled.copiedBuffer(para, CharsetUtil.UTF_8));
        wait();
        return result;
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }

    void setPara(String para) {
        this.para = para;

    }
}

HelloServiceImpl

package com.netty.dubboRPC.provider;

import com.netty.dubboRPC.publicInterface.HelloService;

public class HelloServiceImpl implements HelloService {
    //private int count = 0;
    private static int count = 0;

    @Override
    public String hello(String msg) {
        if (msg != null) {
            return "您好客户端，我已收到：" + msg + "第" + (++count);
        } else {
            return "您好客户端，我收到null";
        }
    }
}

ServerBootstrap

package com.netty.dubboRPC.provider;

import com.netty.dubboRPC.netty.NettyServer;

//启动服务提供者
public class ServerBootstrap {
    public static void main(String[] args) throws Exception {
        NettyServer.startServer("127.0.0.1", 7000);
    }
}

HelloService

package com.netty.dubboRPC.publicInterface;

public interface HelloService {
    String hello(String msg);
}