利用spring-websocket包搭建websocket服务

折腾了将近一天，终于搭建好websocket服务，中间遇到不少的坑，现在记录一下，也供他们参考少走弯路。

开发环境：<spring.version>4.2.5.RELEASE</spring.version>     Tomcat8   jdk8  maven

spring搭建websocket有两种方式：

1、利用javaee-api以注解的形式搭建，见上一篇博文《spring+tomcat8实现websocket 》

2、利用spring-websocket包搭建，本篇介绍的内容。

注意：这种方式必须注释掉这个，不然会冲突

<!-- <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>7.0</version>
        </dependency> -->

需要用到的spring包：

<dependency>  
           <groupId>org.springframework</groupId>  
           <artifactId>spring-websocket</artifactId>  
           <version>${spring.version}</version>  
        </dependency>  
        <dependency>  
           <groupId>org.springframework</groupId>  
           <artifactId>spring-messaging</artifactId>  
           <version>${spring.version}</version>  
        </dependency>
其他辅助包：

<dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson-version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>${jackson-version}</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>${jackson-version}</version>
        </dependency>

Java代码：两个类  WebSocketConfig 和 SystemWebSocketHandler

@Configuration
@EnableWebMvc
@EnableWebSocket
public class WebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer{

	@Override
	public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
		registry.addHandler(systemWebSocketHandler(),"/webSocketServer");
		registry.addHandler(systemWebSocketHandler(),"/webSocketServer/sockjs").setAllowedOrigins("*").withSockJS();
		 //registry.addHandler(systemWebSocketHandler(),"/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor());
		 //registry.addHandler(systemWebSocketHandler(), "/sockjs/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor()).withSockJS();
		 //registry.addHandler(systemWebSocketHandler(), "/webSocketServer/sockjs").withSockJS();
		 /*registry.addHandler(systemWebSocketHandler(),"/ws").addInterceptors(new WebSocketHandshakeInterceptor());
	        registry.addHandler(systemWebSocketHandler(), "/ws/sockjs").addInterceptors(new WebSocketHandshakeInterceptor())
	                .withSockJS();*/
	}
	
	@Bean
    public WebSocketHandler systemWebSocketHandler(){
        return new SystemWebSocketHandler();
    }
	

import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.messaging.Message;
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;

import com.mspj.frame.core.web.controller.BaseWebControllerImpl;

public class SystemWebSocketHandler implements WebSocketHandler {
	 
	private Logger log = LoggerFactory.getLogger(SystemWebSocketHandler.class);
	
    private static final ArrayList<WebSocketSession> users = new ArrayList<WebSocketSession>();;
 
 
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
    	System.out.println("ConnectionEstablished");
    	log.debug("ConnectionEstablished");
        users.add(session);
        
        session.sendMessage(new TextMessage("connect"));
        session.sendMessage(new TextMessage("new_msg"));
        
    }
 
    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
    	System.out.println("handleMessage" + message.toString());
    	log.debug("handleMessage" + message.toString());
        //sendMessageToUsers();
    	session.sendMessage(new TextMessage(new Date() + ""));
    }
 
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        if(session.isOpen()){
            session.close();
        }
        users.remove(session);
        
        log.debug("handleTransportError" + exception.getMessage());
    }
 
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
        users.remove(session);
        log.debug("afterConnectionClosed" + closeStatus.getReason());
        
    }
 
    @Override
    public boolean supportsPartialMessages() {
        return false;
    }
 
    /**
     * 给所有在线用户发送消息
     *
     * @param message
     */
    public void sendMessageToUsers(TextMessage message) {
        for (WebSocketSession user : users) {
            try {
                if (user.isOpen()) {
                    user.sendMessage(message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
 
}

前端调式页面代码

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>WebSocket/SockJS Echo Sample (Adapted from Tomcat's echo sample)</title>
    <style type="text/css">
        #connect-container {
            float: left;
            width: 400px
        }

        #connect-container div {
            padding: 5px;
        }

        #console-container {
            float: left;
            margin-left: 15px;
            width: 400px;
        }

        #console {
            border: 1px solid #CCCCCC;
            border-right-color: #999999;
            border-bottom-color: #999999;
            height: 170px;
            overflow-y: scroll;
            padding: 5px;
            width: 100%;
        }

        #console p {
            padding: 0;
            margin: 0;
        }
    </style>

    <script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>

    <script type="text/javascript">
        var ws = null;
        var url = null;
        var transports = [];

        function setConnected(connected) {
            document.getElementById('connect').disabled = connected;
            document.getElementById('disconnect').disabled = !connected;
            document.getElementById('echo').disabled = !connected;
        }

        function connect() {
            if (!url) {
                alert('Select whether to use W3C WebSocket or SockJS');
                return;
            }
            
			
            //ws = new WebSocket('ws://192.168.10.107:8080/mspjapi/webSocketServer');/* (url.indexOf('sockjs') != -1) ? 
                //new SockJS(url, undefined, {protocols_whitelist: transports}) :  */
                ws = new SockJS("http://192.168.10.107:8080/mspjapi/webSocketServer/sockjs");
                //console.log("http://192.168.10.107:8080/mspjapi/webSocketServer/sockjs");
                
            ws.onopen = function () {
                setConnected(true);
                log('Info: connection opened.');
            };
            
            ws.onmessage = function (event) {
                log('Received: ' + event.data);
            };
            
            ws.onclose = function (event) {
                setConnected(false);
                log('Info: connection closed.');
                log(event);
            };
        }

        function disconnect() {
            if (ws != null) {
                ws.close();
                ws = null;
            }
            setConnected(false);
        }

        function echo() {
            if (ws != null) {
                var message = document.getElementById('message').value;
                log('Sent: ' + message);
                ws.send(message);
            } else {
                alert('connection not established, please connect.');
            }
        }

        function updateUrl(urlPath) {
            if (urlPath.indexOf('sockjs') != -1) {
                url = urlPath;
                document.getElementById('sockJsTransportSelect').style.visibility = 'visible';
            }
            else {
              if (window.location.protocol == 'http:') {
                  url = 'ws://' + window.location.host + urlPath;
              } else {
                  url = 'wss://' + window.location.host + urlPath;
              }
              document.getElementById('sockJsTransportSelect').style.visibility = 'hidden';
            }
        }

        function updateTransport(transport) {
          transports = (transport == 'all') ?  [] : [transport];
        }
        
        function log(message) {
            var console = document.getElementById('console');
            var p = document.createElement('p');
            p.style.wordWrap = 'break-word';
            p.appendChild(document.createTextNode(message));
            console.appendChild(p);
            while (console.childNodes.length > 25) {
                console.removeChild(console.firstChild);
            }
            console.scrollTop = console.scrollHeight;
        }
    </script>
</head>
<body>
<noscript><h2 style="color: #ff0000">Seems your browser doesn't support Javascript! Websockets 
    rely on Javascript being enabled. Please enable
    Javascript and reload this page!</h2></noscript>
<div>
    <div id="connect-container">
        <input id="radio1" type="radio" name="group1" onclick="updateUrl('/mspjapi');">
            <label for="radio1">W3C WebSocket</label>
        <br>
        <input id="radio2" type="radio" name="group1" onclick="updateUrl('/spring-websocket-test/sockjs/echo');">
            <label for="radio2">SockJS</label>
        <div id="sockJsTransportSelect" style="visibility:hidden;">
            <span>SockJS transport:</span>
            <select onchange="updateTransport(this.value)">
              <option value="all">all</option>
              <option value="websocket">websocket</option>
              <option value="xhr-polling">xhr-polling</option>
              <option value="jsonp-polling">jsonp-polling</option>
              <option value="xhr-streaming">xhr-streaming</option>
              <option value="iframe-eventsource">iframe-eventsource</option>
              <option value="iframe-htmlfile">iframe-htmlfile</option>
            </select>
        </div>
        <div>
            <button id="connect" onclick="connect();">Connect</button>
            <button id="disconnect" disabled="disabled" onclick="disconnect();">Disconnect</button>
        </div>
        <div>
            <textarea id="message" style="width: 350px">Here is a message!</textarea>
        </div>
        <div>
            <button id="echo" onclick="echo();" disabled="disabled">Echo message</button>
        </div>
    </div>
    <div id="console-container">
        <div id="console"></div>
    </div>
</div>

<a href="echoendpoint.jsp">echoendpoint test</a>
<a href="websocket2.jsp">echoendpoint test</a>

</body>
</html>

最后说下几个坑点：

1、html页面访问限制的问题的：403 Forbidden

registry.addHandler(systemWebSocketHandler(),"/webSocketServer/sockjs").setAllowedOrigins("*").withSockJS();

2、web.xml配置需要升级成3.1

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">

3、web.xml里面所有过滤器需要加上

<async-supported>true</async-supported>

如：

<servlet>
        <servlet-name>SpringMVC</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
        <async-supported>true</async-supported>
    </servlet>