[网络协议]区块链中Java基于WebSocket构建P2P网络

一、pom依赖

       <dependency>
            <groupId>org.java-websocket</groupId>
            <artifactId>Java-WebSocket</artifactId>
            <version>1.5.1</version>
        </dependency>

二、服务端代码

package com.peck.blockchain.p2p;

import org.java_websocket.WebSocket;
import org.java_websocket.handshake.ClientHandshake;
import org.java_websocket.server.WebSocketServer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.testng.util.Strings;

import javax.annotation.PostConstruct;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

/**
 * @author songanning
 * @ClassName:P2pPointServer
 * @Description:基于springBoot的WebSocket服务端
 * @Date:2021/11/23 10:18
 */
@Component
public class P2pPointServer {
    /**
    * 日志记录
    */
    private Logger logger = LoggerFactory.getLogger(P2pPointServer.class);

    /**
    * 本机Server的WebSocket端口
     * 多机测试可以改变该值
    */
    private int port = 7001;

    /**
    * 所有连接到服务端的WebSocket缓存器
    */
    private List<WebSocket> localSockets = new ArrayList<WebSocket>();

    public List<WebSocket> getLocalSockets() {
        return localSockets;
    }

    public void setLocalSockets(List<WebSocket> localSockets) {
        this.localSockets = localSockets;
    }

    /**
     * 初始化P2P Server端
     *
     */
    @PostConstruct
    @Order(1)
    public void initServer() {
        /**
        * 初始化WebSocket的服务端定义内部类对象socketServer，源于WebSocketServer；
         * new InetSocketAddress(port) 是WebSocketServer构造器的参数
         * InetSocketAddress是（Ip地址+端口号）类型，即端口地址类型
        */
        final WebSocketServer socketServer = new WebSocketServer(new InetSocketAddress(port)) {
            /**
            * 重写5个事件方法，事件发生时触发对应的方法
            */
            @Override
            //创建连接成功时触发
            public void onOpen(WebSocket webSocket, ClientHandshake clientHandshake) {
                sendMessage(webSocket,"北京服务端成功创建连接");
                //当成功创建一个WebSocket连接时，将该链接加入连接池
                localSockets.add(webSocket);
            }

            @Override
            //断开连接时触发
            public void onClose(WebSocket webSocket, int i, String s, boolean b) {
                logger.info(webSocket.getRemoteSocketAddress() + "客户端与服务器断开连接！");
                //当客户端断开连接时，WebSocket连接池删除该链接
                localSockets.remove(webSocket);
            }

            @Override
            //收到客户端发送来的消息时触发
            public void onMessage(WebSocket webSocket, String msg) {
                logger.info("北京服务端接收到客户端消息：" + msg);
                sendMessage(webSocket,"收到消息");
            }

            @Override
            //连接发生错误时调用，紧接着触发onClose方法
            public void onError(WebSocket webSocket, Exception e) {
                logger.info(webSocket.getRemoteSocketAddress() + "客户端连接错误！");
                localSockets.remove(webSocket);
            }

            @Override
            public void onStart() {
                logger.info("北京服务端监听socketServer端启动......");
            }
        };
        socketServer.start();
        logger.info("北京服务端监听socketServer端口：" + port);
    }
    /**
    * 向连接到本机的某客户端发送消息
    */
    public void sendMessage(WebSocket ws,String message) {
        logger.info("发送给" + ws.getRemoteSocketAddress().getPort() + "的篇p2p消息是：" + message);
        ws.send(message);
    }

    /**
     * 向所有连接到本机的客户端广播消息
     * @param message
     */
    public void broatcast(String message) {
        if (localSockets.size() == 0 || Strings.isNullOrEmpty(message)) {
            return;
        }

        logger.info("Glad to say broatcast to clients being startted!");
        for (WebSocket socket : localSockets) {
            this.sendMessage(socket,message);
        }
        logger.info("Glad to say broatcast to clients has overred!");
    }
}

三、客户端代码

package com.peck.blockchain.p2p;

import org.java_websocket.WebSocket;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.handshake.ServerHandshake;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import org.testng.util.Strings;

import javax.annotation.PostConstruct;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.List;


/**
 * @author songanning
 * @ClassName:P2pPointClient
 * @Description:基于SpringBoot的WebSocket客户端
 * @Date:2021/11/23 11:09
 */
@Component
public class P2pPointClient {
    /**
    * 日志记录
    */
    private Logger logger = LoggerFactory.getLogger(P2pPointClient.class);

    /**
    * p2p 网络中的节点既是服务端，又是客户端。作为服务端运行在7001端口
     * (P2pPointServer 的port字段)，同时作为客户通过ws://localhost:7001连接到服务器
    */
    private String wsUrl = "ws://localhost:7001/";

    /**
    * 所有客户端WebSocket的连接池缓存
    */
    private List<WebSocket> localSockets = new ArrayList<>();

    public List<WebSocket> getLocalSockets() {
        return localSockets;
    }

    public void setLocalSockets(List<WebSocket> localSockets) {
        this.localSockets = localSockets;
    }

    /**
    * 连接到服务器
    */
    @PostConstruct
    @Order(2)
    public void connentPeer() {
        try {
            final WebSocketClient socketClient = new WebSocketClient(new URI(wsUrl)) {
                @Override
                public void onOpen(ServerHandshake serverHandshake) {
                    sendMessage(this,"北京客户端成功创建客户端");
                    localSockets.add(this);
                }

                @Override
                public void onMessage(String msg) {
                    logger.info("北京客户端收到北京服务端发送的消息：" + msg);
                }

                @Override
                public void onClose(int i, String s, boolean b) {
                    logger.info("北京客户端关闭");
                    localSockets.remove(this);
                }

                @Override
                public void onError(Exception e) {
                    logger.info("北京客户端报错");
                    localSockets.remove(this);
                }
            };
            //客户端开始连接服务端
            socketClient.connect();
        }catch (URISyntaxException e) {
            e.printStackTrace();
        }
    }

    /**
     * 向服务端发送消息，当前WebSocket的远程Socket地址就是服务端
     * @param ws
     * @param message
     */
    public void sendMessage(WebSocket ws,String message) {
        logger.info("发送给" + ws.getRemoteSocketAddress().getPort() + "的p2p消息：" + message);
        ws.send(message);
    }

    /**
     * 向所有连接过的服务端广播消息
     * @param message 待广播的消息
     */
    public void broadcast(String message) {
        if (localSockets.size() == 0 || Strings.isNullOrEmpty(message)) {
            return;
        }
        logger.info("Glad to say broatcast to servers being startted!");
        for (WebSocket socket:localSockets) {
            this.sendMessage(socket,message);
        }
        logger.info("Glad to say broatcast to servers has overred!");
    }
}

四、运行截图