Error during WebSocket handshake: Unexpected response code: 200

前端建立websocket链接的时候，控制台打印Error during WebSocket handshake: Unexpected response code: 200，
这种情况多半是因为服务端的拦截器出了问题。

要知道websocket是基于http的，建立websocket链接的时候也用经过握手，这个握手走的就是传统的http请求（好像不同浏览器实现的细节也不太一样，chrome应该是走的http），因此如果服务端有拦截器的话，是会把握手信息拦截下来的。

解决办法：
我的服务端是springboot+shrio， 解决办法很简单

@Configuration
public class ShiroConfig {

    /**
     * Shiro的Web过滤器Factory 命名:shiroFilter
 * * @param securityManager * @return
     */
    @Bean(name = "shiroFilter")
    public ShiroFilterFactoryBean shiroFilterFactoryBean(SecurityManager securityManager) {
        System.out.println(("注入Shiro的Web过滤器-->shiroFilter" + ShiroFilterFactoryBean.class));
        ShiroFilterFactoryBean shiroFilterFactoryBean = new ShiroFilterFactoryBean();

        shiroFilterFactoryBean.setSecurityManager(securityManager);
        shiroFilterFactoryBean.setLoginUrl("/user/login");
        shiroFilterFactoryBean.setSuccessUrl("/index");
        shiroFilterFactoryBean.setUnauthorizedUrl("/403");
        Map<String, String> filterChainDefinitionMap = new LinkedHashMap<String, String>();
        filterChainDefinitionMap.put("/logout", "logout");

        filterChainDefinitionMap.put("/user/login", "anon");
        filterChainDefinitionMap.put("/websocket", "anon"); //避免拦截/websocket链接
        filterChainDefinitionMap.put("/reg", "anon");
        filterChainDefinitionMap.put("/plugins/**", "anon");
        filterChainDefinitionMap.put("/pages/**", "anon");
        filterChainDefinitionMap.put("/api/**", "anon");
        filterChainDefinitionMap.put("/dists/img/*", "anon");
        filterChainDefinitionMap.put("/**", "authc");

        shiroFilterFactoryBean.setFilterChainDefinitionMap(filterChainDefinitionMap);
        shiroFilterFactoryBean.getFilters().put("authc",  new MyFormAuthenticationFilter());


        return shiroFilterFactoryBean;
    }
   }

核心代码其实就这一行 filterChainDefinitionMap.put("/websocket", “anon”);

另外附上我的websocket配置：

@Configuration
public class WebsocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}

/**
 * 坑点：
 * \@ServerEndpoint注解的类，不可以用AOP， 否则会出现无法注入的情况
 */
@ServerEndpoint(value = "/websocket")
@Component
public class WSServer {
    private static Hashtable<String, WSServer> websocketTable = new Hashtable<>();

    private static final String TYPE_INIT = "0";
    private static final String TYPE_EXCEPTION = "-1";
    private Session session;
    
    //心跳定时器
    private Timer pulsTimer;
    private long timerPeriod = 45 * 1000;
    private String userName;    //标识用户

    @OnOpen
    public void onOpen(Session session){
        this.session = session;

        //第一个链接后，启动定时器发送定时心跳
        if(pulsTimer == null){
            pulsTimer = new Timer();
            pulsTimer.schedule(new TimerTask() {
                @Override
                public void run() {
                    try {
                        WSServer.broadcast(WSMessage.pulseMessage());
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }
            }, 0L, timerPeriod);
        }
    }

    @OnClose
    public void onClose() {
        if(!StringUtils.isEmpty(userName)){
            websocketTable.remove(userName);
        }
    }

    /**
     * {
     *     type:"1",
     *     message:"JSON",
     *     rdnum："用来唯一标识这条消息的id"
     * }
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        try {
            JSONObject jsonObject = JSONObject.parseObject(message);
            String type = jsonObject.getString("type");
            switch (type){
                case TYPE_INIT: init(jsonObject);break;
                default:;
            }
        }catch (JSONException e){
            e.printStackTrace();
            WSMessage wsMessage = new WSMessage(TYPE_EXCEPTION, "json格式出错");
            sendMessage(wsMessage);
        }

    }

    @OnError
    public void onError(Session session, Throwable error) {
        error.printStackTrace();
    }


    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }

    public void sendMessage(WSMessage message){
        try {
            sendMessage(message.toString());
        }catch (IOException e){
            e.printStackTrace();
        }
    }

    public void init(JSONObject jsonObject){
        JSONObject messge = jsonObject.getJSONObject("message");
        if(messge != null){
            String userName = messge.getString("userName");
            if(StringUtils.isEmpty(userName)){
                websocketTable.put(userName, this);
            }
        }
    }


    public static synchronized void broadcast(String message)  throws IOException{
        for(Iterator<String> iterator = websocketTable.keySet().iterator(); iterator.hasNext(); ){
            WSServer wsServer = websocketTable.get(iterator.next());
            wsServer.sendMessage(message);
        }
    }

    public static synchronized void broadcast(WSMessage message)  throws IOException{
        broadcast(message.toString());
    }

    public static synchronized void broadcast(WSMessage message, String userName)  throws IOException{
        broadcast(message.toString(), userName);
    }

    public static synchronized void broadcast(String message, String userName)  throws IOException{
        WSServer wsServer = websocketTable.get(userName);
        if(wsServer != null){
            wsServer.sendMessage(message);
        }
    

    public static synchronized int getOnlineCount() {
        return websocketTable.size();
    }
}

看都看到这儿了，点个赞再走呗(。・∀・)ノ