基于java做一个socket.io客户端

前言

最近公司这边让我去订阅一个第三方机构的websocket server，也是头疼，免不了和对方各种沟通，大家都很忙，收到回复很慢，开发方向也不知道。先是做了一个普通websocket的客户端，但后面了解到对方是基于socket.io做的一个server，又重新做了一个基于socket.io-client-java开源库的客户端。涉及到公司商业机密，所以做了一个demo，转自https://blog.csdn.net/q56231293811/article/details/84873776

1. Client(Socket.IO Client Library for Java)

先上代码

package com.dasnnj.practice.share.socket;

import io.socket.client.IO;
import io.socket.client.Socket;

import java.util.Arrays;

/**
 * Description <P> TODO : socket.io client端 <P>
 *
 * @author DASNNJ <a href="mailto:dasnnj@outlook.com"> dasnnj@outlook.com </a>
 * @date 2019-04-27 18:32
 */
public class Client {

    public static void main(String[] args) {
        String url = "http://localhost:9999";
        try {
            IO.Options options = new IO.Options();
            options.transports = new String[]{"websocket"};
            //失败重试次数
            options.reconnectionAttempts = 10;
            //失败重连的时间间隔
            options.reconnectionDelay = 1000;
            //连接超时时间(ms)
            options.timeout = 500;
            final Socket socket = IO.socket(url, options);
            //监听自定义msg事件
            socket.on("msg", objects -> System.out.println("client: 收到msg->" + Arrays.toString(objects)));
	    //监听自定义订阅事件	
            socket.on("sub", objects -> System.out.println("client: " + "订阅成功，收到反馈->" + Arrays.toString(objects)));
            socket.on(Socket.EVENT_CONNECT, objects -> {
                socket.emit("sub", "我是訂閲對象");
                System.out.println("client: " + "连接成功");
            });
            socket.on(Socket.EVENT_CONNECTING, objects -> System.out.println("client: " + "连接中"));
            socket.on(Socket.EVENT_CONNECT_TIMEOUT, objects -> System.out.println("client: " + "连接超时"));
            socket.on(Socket.EVENT_CONNECT_ERROR, objects -> System.out.println("client: " + "连接失败"));
            socket.connect();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
} 

流程：

1. 启动client会创建scoket,并将uri,options等参数set进去

2. 监听一些事件（可自定义），也就是将event为key，回调为value，put 进callbacks(其为ConcurrentMap)
   

3. connect 主动连接

4. 当连接成功时候会触发Socket.EVENT_CONNECT事件，执行了socket.emit("sub", "我是訂閲對象");订阅操作

2. Server(Socket.IO服务器的开源Java实现。基于Netty服务器框架。)

这边server只监听了sub事件（server监听client emit(提交)的sub事件,而client监听的是server emit（反馈）的sub事件）和断开连接事件，并循环发送广播消息（smg事件）

package com.dasnnj.practice.share.socket;

import com.corundumstudio.socketio.Configuration;
import com.corundumstudio.socketio.SocketIOServer;

import java.util.Map;

/**
 * Description <P> TODO : socket.io server端 <P>
 *
 * @author DASNNJ <a href="mailto:dasnnj@outlook.com"> dasnnj@outlook.com </a>
 * @date 2019-04-27 18:31
 */

public class Server {
    public static void main(String[] args) {
        Configuration config = new Configuration();
        config.setHostname("localhost");
        config.setPort(9999);
        SocketIOServer server = new SocketIOServer(config);
        server.addConnectListener(client -> {
            System.out.println("server: " + client.getRemoteAddress() + "客户端连接成功");
        });
	//添加sub事件
        server.addEventListener("sub", String.class, (client, data, ackRequest) -> {
            String c= client.getRemoteAddress().toString();
            //获取客户端url参数
            Map params = client.getHandshakeData().getUrlParams();
            System.out.println("server: " + c+ "：客户端：订阅成功，订阅信息為->" + data);
            //sub事件成功反馈
            client.sendEvent("sub", c+ "客户端你好，我是服务端，你订阅成功了");
        });

        //添加客户端断开连接事件
        server.addDisconnectListener(client -> {
            String c= client.getRemoteAddress().toString();
            //获取设备ip
            String clientIp = c.substring(1, c.indexOf(":"));
            System.out.println("server: " + clientIp + "-------------------------" + "客户端已断开连接");
        });
        server.start();
        int i = 0;
        while (true) {
            try {
                Thread.sleep(1500);
                //广播消息
                i++;
                server.getBroadcastOperations().sendEvent("msg", "30", "hello" + i, "false");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
}

3. pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.dasnnj.practice</groupId>
  <artifactId>practice</artifactId>
  <version>1.0-SNAPSHOT</version>
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <configuration>
          <source>8</source>
          <target>8</target>
        </configuration>
      </plugin>
    </plugins>
  </build>


  <dependencies>
    <dependency>
      <groupId>io.socket</groupId>
      <artifactId>socket.io-client</artifactId>
      <version>1.0.0</version>
    </dependency>
    <dependency>
      <groupId>com.corundumstudio.socketio</groupId>
      <artifactId>netty-socketio</artifactId>
      <version>1.7.16</version>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-nop</artifactId>
      <version>1.7.2</version>
    </dependency>
  </dependencies>
</project>

4. 再次感谢

转自 java netty-socketio 与 io.socket的使用，当时看了这位大佬的教程解决了问题