springboot整合socketio，实现后端websocket通讯

服务端需要使用 netty-socketio ，示例项目 netty-socketio-demo ，基本上看看demo示例项目就能很快上手了，但是demo中的示例代码场景为js做客户端，如果需要在java中连接websocket server，可以参考下面的示例：

package com.me.learn.socket.server;
import com.corundumstudio.socketio.AckRequest;
import com.corundumstudio.socketio.Configuration;
import com.corundumstudio.socketio.SocketIOClient;
import com.corundumstudio.socketio.SocketIOServer;
import com.corundumstudio.socketio.listener.ConnectListener;
import com.corundumstudio.socketio.listener.DataListener;
import io.socket.engineio.client.Socket;
public class DemoSocketServer {
    public static void main(String[] args) throws InterruptedException {
        Configuration config = new Configuration();
        config.setHostname("localhost");
        config.setPort(9092);
        final SocketIOServer server = new SocketIOServer(config);
        server.addConnectListener(new ConnectListener() {
            @Override
            public void onConnect(SocketIOClient client) {
                String token = client.getHandshakeData().getUrlParams().get("token").get(0);
                if (!token.equals("8888888")) {
                    client.disconnect();//校验token示例
                }
                System.out.println("sessionId:" + client.getSessionId() + ",token:" + token);
            }
        });
        server.addEventListener(Socket.EVENT_MESSAGE, String.class, new DataListener<String>() {
            @Override
            public void onData(SocketIOClient client, String data, AckRequest ackSender) throws Exception {
                System.out.println("client data:" + data);
                server.getBroadcastOperations().sendEvent(Socket.EVENT_MESSAGE, "hi");
            }        });
        server.start();
        Thread.sleep(Integer.MAX_VALUE);
        server.stop();
    }}

客户端是需使用 socket.io-client-java

package com.me.learn.socket.client;
import io.socket.client.IO;
import io.socket.client.Socket;
import io.socket.emitter.Emitter;
import java.net.URISyntaxException;
public class DemoSocketClient {
    public static void main(String[] args) throws URISyntaxException, InterruptedException {
        IO.Options options = new IO.Options();
        options.transports = new String[]{"websocket"};
        options.reconnectionAttempts = 2;
        options.reconnectionDelay = 1000;//失败重连的时间间隔
        options.timeout = 500;//连接超时时间(ms)//
        final Socket socket = IO.socket("http://localhost:9092/?token=123456", options);//错误的token值连接示例
        final Socket socket = IO.socket("http://localhost:9092/?token=8888888", options);
        socket.on(Socket.EVENT_CONNECT, new Emitter.Listener() {
            @Override
            public void call(Object... args) {
                socket.send("hello");
            }
        });
        socket.on(Socket.EVENT_DISCONNECT, new Emitter.Listener() {
            @Override
            public void call(Object... args) {
                System.out.println("连接关闭");
            }
        });
        socket.on("message", new Emitter.Listener() {
            @Override
            public void call(Object... args) {
                System.out.println("sessionId:" + socket.id());
                for (Object obj : args) {
                    System.out.println(obj);
                }
                System.out.println("收到服务器应答，将要断开连接...");
                socket.disconnect();
            }
        });
        socket.connect();
    }}

注意：以上实现通讯的代码从开源项目的demo做参考即可实现，这里需要注意的是版本不兼容的问题，正常运行版本要求：netty-socketio 为1.7.x版本 socket.io-client 为1.0.x版本