Spring Boot SockJS应用例子

1.SockJS用javascript实现的socket连接，兼容各种浏览器的WebSocket支持库
2.WebSocket是H5的，不支持H5的浏览器没法使用。
3.SockJS它提供类似于websocket的编程模式但是可以适应不同的浏览器（包括不支持websocket的浏览器）。


后端代码：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

package com.cesmart;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.ComponentScan;

@EnableAutoConfiguration
@ComponentScan(basePackages = "com.cesmart") // 扫描那些包得到bean.@ComponentScan({"com.teradata.notification","com.teradata.dal"})
public class Application {
    public static void main(String[] args) {
        ApplicationContext applicationContext = SpringApplication.run(Application.class, args);
    }
}

package com.cesmart.config;

import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;

public class MyHandler implements WebSocketHandler {
    // 连接继开处理
    @Override
    public void afterConnectionClosed(WebSocketSession arg0, CloseStatus arg1) throws Exception {
        // TODO Auto-generated method stub

        System.out.println("Connection closed..." + arg0.getRemoteAddress().toString());

    }

    // 连接建立处理
    @Override
    public void afterConnectionEstablished(WebSocketSession arg0) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("Connection established..." + arg0.getRemoteAddress().toString());
    }

    // 接收、发送信息处理
    @Override
    public void handleMessage(WebSocketSession arg0, WebSocketMessage<?> arg1) throws Exception {
        // TODO Auto-generated method stub
        try {
            System.out.println("Req: " + arg1.getPayload());
            // 发送信息
            TextMessage returnMessage = new TextMessage(arg1.getPayload() + " received at server");
            arg0.sendMessage(returnMessage);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // 错误处理（客户端突然关闭等接收到的错误）
    @Override
    public void handleTransportError(WebSocketSession arg0, Throwable arg1) throws Exception {
        // TODO Auto-generated method stub
        if (arg0.isOpen()) {
            arg0.close();
        }
        System.out.println(arg1.toString());
        System.out.println("WS connection error,close...");
    }

    @Override
    public boolean supportsPartialMessages() {
        // TODO Auto-generated method stub
        return false;
    }
}

package com.cesmart.config;

import java.util.Map;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;

/**
 * 类描述：拦截器
 */
public class MyHandshakeInterceptor extends HttpSessionHandshakeInterceptor {

    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
            Exception ex) {
        // TODO Auto-generated method stub
        System.out.println("After handshake " + request.getRemoteAddress().toString());
        super.afterHandshake(request, response, wsHandler, ex);
    }

    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler handler,
            Map<String, Object> map) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("Before handshake " + request.getRemoteAddress().toString());
        return super.beforeHandshake(request, response, handler, map);
    }

}

package com.cesmart.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;

@Configuration // 配置类
@EnableWebSocket // 声明支持websocket
public class WebSocketConfig implements WebSocketConfigurer {

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        // 注册websocket实现类，指定参数访问地址;allowed-origins="*" 允许跨域
        // addHandler是增加处理接口和设定URL
        // addInterceptors是增加拦截器处理（可以不用）
        registry.addHandler(myHandler(), "/ws").addInterceptors(myHandshake()).setAllowedOrigins("*");
        registry.addHandler(myHandler(), "/sockjs/ws").addInterceptors(myHandshake()).withSockJS();

        registry.addHandler(myHandler(), "/ws2").setAllowedOrigins("*");
        registry.addHandler(myHandler(), "/sockjs/ws2").setAllowedOrigins("*").withSockJS();
    }

    @Bean
    public MyHandler myHandler() {
        return new MyHandler();
    }

    @Bean
    public MyHandshakeInterceptor myHandshake() {
        return new MyHandshakeInterceptor();
    }
}

前端代码：

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Insert title here</title>
    <script type="text/javascript" src="//cdn.bootcss.com/sockjs-client/1.1.1/sockjs.min.js"></script>
    <script type="text/javascript">
        var url = "127.0.0.1:8090/";
        var websocket = null;
        if ('WebSocket' in window) {
            websocket = new WebSocket("ws://" + url + "/ws");//建立连接
        } else {
            websocket = new SockJS("http://" + url + "/sockjs/ws");//建立连接
        }
        //建立连接处理
        websocket.onopen = onOpen;
        //接收处理
        websocket.onmessage = onMessage;
        //错误处理
        websocket.onerror = onError;
        //断开连接处理
        websocket.onclose = onClose;

        function onOpen(openEvent) {
            document.getElementById("console").innerHTML = document.getElementById("console").innerHTML+ "OPEN<br/>";
        }

        function onMessage(event) {
            document.getElementById("console").innerHTML = document.getElementById("console").innerHTML+ event.data+"<br/>";
        }
        function onError() {
        }
        function onClose() {
            document.getElementById("console").innerHTML = document.getElementById("console").innerHTML+ "CLOSE<br/>";
        }

        function doSend() {
            console.log(websocket.readyState);
            if (websocket.readyState == SockJS.OPEN) {
                var msg = document.getElementById("message").value;
                //发送消息
                websocket.send(msg);
            } else {
                alert("连接失败!");
            }
        }


        function disconnect(){
            if (websocket != null) {
                websocket.close();
                websocket = null;
            }
        }

        function reconnect(){
            if (websocket != null) {
                websocket.close();
                websocket = null;
            }
            if ('WebSocket' in window) {
               websocket = new WebSocket("ws://" + url + "/ws");
            } else {
                websocket = new SockJS("http://" + url + "/sockjs/ws");
            }
            websocket.onopen = onOpen;
            websocket.onmessage = onMessage;
            websocket.onerror = onError;
            websocket.onclose = onClose;
        }
    </script>
</head>
<body>
<div>
    <button id="disconnect" onclick="disconnect()">断开连接</button>
    <button id="send" onclick="doSend()">发送消息</button>
    <button id="reconnect" onclick="reconnect()">重新连接</button>
</div>
<div>
    <textarea id="message" style=" 350px">Here is a message!</textarea>
</div>
<div>日志信息：</div>
<p id="console" width="600px"></p>
</body>
</html>

参考（websocket简单应用）：http://wiselyman.iteye.com/blog/2003336
参考（应用例子）：http://768992698.iteye.com/blog/2338250
参考（应用例子（TextWebSocketHandler ））：http://www.cnblogs.com/likun10579/p/5594828.html