spring WebSocket示例详解

<dependency>
  <groupId>javax.websocket</groupId>
  <artifactId>javax.websocket-api</artifactId>
  <version>1.0</version>
  <scope>provided</scope>
</dependency>
<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-websocket</artifactId>
  <version>4.1.4.RELEASE</version>
</dependency>

@Configuration
@EnableWebMvc
@EnableWebSocket
public class WebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {
  @Override
  public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
    //允许连接的域,只能以http或https开头
    String[] allowsOrigins = {"http://www.xxx.com"};
    
    //WebIM WebSocket通道
    registry.addHandler(chatWebSocketHandler(),"/      webSocketIMServer").setAllowedOrigins(allowsOrigins).addInterceptors(myInterceptor());
    registry.addHandler(chatWebSocketHandler(), "/sockjs/w     ebSocketIMServer").setAllowedOrigins(allowsOrigins).addInterceptors(myInterceptor()).withSockJS();
  }
  @Bean
  public ChatWebSocketHandler chatWebSocketHandler() {
    return new ChatWebSocketHandler();
  }
  @Bean
  public WebSocketHandshakeInterceptor myInterceptor(){
    return new WebSocketHandshakeInterceptor();
  }
}

public class WebSocketHandshakeInterceptor implements HandshakeInterceptor {

  @Override
  public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object
        > attributes) throws Exception {
    if (request instanceof ServletServerHttpRequest) {
      attributes.put("username",userName);
    }
    return true;
  }

  @Override
  public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {

  }
}

public class ChatWebSocketHandler extends TextWebSocketHandler{
  
  private final static List<WebSocketSession> sessions = Collections.synchronizedList(new ArrayList<WebSocketSession>());
  //接收文本消息，并发送出去
  @Override
  protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
    chatTextMessageHandler(message.getPayload());
    super.handleTextMessage(session, message);
  }
  //连接建立后处理
  @SuppressWarnings("unchecked")
  @Override
  public void afterConnectionEstablished(WebSocketSession session) throws Exception {
    logger.debug("connect to the websocket chat success......");
    sessions.add(session);
    //处理离线消息
  }
  //抛出异常时处理
  @Override
  public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
    if(session.isOpen()){
      session.close();
    }
    logger.debug("websocket chat connection closed......");
    sessions.remove(session);
  }
  //连接关闭后处理
  @Override
  public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
    logger.debug("websocket chat connection closed......");
    sessions.remove(session);
  }

  @Override
  public boolean supportsPartialMessages() {
    return false;
  }
}

var host = window.location.host;
var websocket;
if ('WebSocket' in window) {
  websocket = new ReconnectingWebSocket("ws://"
    + host + "/webSocketIMServer", null, {debug:true, maxReconnectAttempts:4});
} else if ('MozWebSocket' in window) {
  websocket = new MozWebSocket("ws://" + host
    + "/webSocketIMServer");
} else {
  websocket = new SockJS("http://" + host
      + "/sockjs/webSocketIMServer");
}
websocket.onopen = function(evnt) {
  console.log("websocket连接上");
};
websocket.onmessage = function(evnt) {
  messageHandler(evnt.data);
};
websocket.onerror = function(evnt) {
  console.log("websocket错误");
};
websocket.onclose = function(evnt) {
  console.log("websocket关闭");
}