160601、Websocet服务端实现

今天是六一儿童节，祝愿小朋友们节日快乐！大朋友们事事顺心！

Websocet服务端实现

WebSocketConfig.Java

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

@Configuration @EnableWebMvc @EnableWebSocket public class WebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {     @Override     public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {         registry.addHandler(systemWebSocketHandler(),"/webSocketServer").addInterceptors(newWebSocketHandshakeInterceptor());           registry.addHandler(systemWebSocketHandler(), "/sockjs/webSocketServer").addInterceptors(newWebSocketHandshakeInterceptor())                 .withSockJS();     }       @Bean     public WebSocketHandler systemWebSocketHandler(){         return new SystemWebSocketHandler();     }   }

不要忘记在springmvc的配置文件中配置对此类的自动扫描

?

1	<context:component-scan base-package="com.ldl.origami.websocket" />

@Configuration

@EnableWebMvc
@EnableWebSocket
这三个大致意思是使这个类支持以@Bean的方式加载bean，并且支持springmvc和websocket，不是很准确大致这样，试了一下@EnableWebMvc不加也没什么影响，@Configuration本来就支持springmvc的自动扫描

?

1	registry.addHandler(systemWebSocketHandler(),"/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor())

用来注册websocket server实现类，第二个参数是访问websocket的地址

?

1 2 3

registry.addHandler(systemWebSocketHandler(), "/sockjs/webSocketServer").addInterceptors(new WebSocketHandshakeInterceptor())                 .withSockJS();     }

这个是使用Sockjs的注册方法

首先SystemWebSocketHandler.java

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91

public class SystemWebSocketHandler implements WebSocketHandler {       private static final Logger logger;       private static final ArrayList<WebSocketSession> users;       static {         users = new ArrayList<>();         logger = LoggerFactory.getLogger(SystemWebSocketHandler.class);     }       @Autowired     private WebSocketService webSocketService;       @Override     public void afterConnectionEstablished(WebSocketSession session) throws Exception {         logger.debug("connect to the websocket success......");         users.add(session);         String userName = (String) session.getAttributes().get(Constants.WEBSOCKET_USERNAME);         if(userName!= null){             //查询未读消息             int count = webSocketService.getUnReadNews((String) session.getAttributes().get(Constants.WEBSOCKET_USERNAME));               session.sendMessage(new TextMessage(count + ""));         }     }       @Override     public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {           //sendMessageToUsers();     }       @Override     public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {         if(session.isOpen()){             session.close();         }         logger.debug("websocket connection closed......");         users.remove(session);     }       @Override     public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {         logger.debug("websocket connection closed......");         users.remove(session);     }       @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();             }         }     }       /**      * 给某个用户发送消息      *      * @param userName      * @param message      */     public void sendMessageToUser(String userName, TextMessage message) {         for (WebSocketSession user : users) {             if (user.getAttributes().get(Constants.WEBSOCKET_USERNAME).equals(userName)) {                 try {                     if (user.isOpen()) {                         user.sendMessage(message);                     }                 } catch (IOException e) {                     e.printStackTrace();                 }                 break;             }         }     } }

相关内容大家一看就能明白，就不多解释了

然后WebSocketHandshakeInterceptor.java

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

public class WebSocketHandshakeInterceptor implements HandshakeInterceptor {       private static Logger logger = LoggerFactory.getLogger(HandshakeInterceptor.class);     @Override     public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object                 > attributes) throws Exception {         if (request instanceof ServletServerHttpRequest) {             ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;             HttpSession session = servletRequest.getServletRequest().getSession(false);             if (session != null) {                 //使用userName区分WebSocketHandler，以便定向发送消息                 String userName = (String) session.getAttribute(Constants.SESSION_USERNAME);                 attributes.put(Constants.WEBSOCKET_USERNAME,userName);             }         }         return true;     }       @Override     public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception exception) {       } }

这个的主要作用是取得当前请求中的用户名，并且保存到当前的WebSocketHandler中，以便确定WebSocketHandler所对应的用户，具体可参考HttpSessionHandshakeInterceptor

用户登录建立websocket连接

index.jsp

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

<script type="text/javascript" src="http://localhost:8080/Origami/websocket/sockjs-0.3.min.js"></script>         <script>             var websocket;             if ('WebSocket' in window) {                 websocket = new WebSocket("ws://localhost:8080/Origami/webSocketServer");             } else if ('MozWebSocket' in window) {                 websocket = new MozWebSocket("ws://localhost:8080/Origami/webSocketServer");             } else {                 websocket = new SockJS("http://localhost:8080/Origami/sockjs/webSocketServer");             }             websocket.onopen = function (evnt) {             };             websocket.onmessage = function (evnt) {                 $("#msgcount").html("(<font color='red'>"+evnt.data+"</font>)")             };             websocket.onerror = function (evnt) {             };             websocket.onclose = function (evnt) {             }           </script>

使用sockjs时要注意

1、这两个的写法

?

1	<script type="text/javascript" src="http://localhost:8080/Origami/websocket/sockjs-0.3.min.js"></script>

?

1	websocket = new SockJS("http://localhost:8080/Origami/sockjs/webSocketServer");

2、web.xml中

?

1 2 3

<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_1.xsd">

?

1

version

?

1	web-app_3_1.xsd

这两个的版本都要是3.0+

然后在这个servlet中加入

?

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

?

1 2 3 4 5 6 7 8 9 10

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

然后所有的filter中也加入

?

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

3、添加相关依赖

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

<dependency>             <groupId>com.fasterxml.jackson.core</groupId>             <artifactId>jackson-annotations</artifactId>             <version>2.3.0</version>         </dependency>         <dependency>             <groupId>com.fasterxml.jackson.core</groupId>             <artifactId>jackson-core</artifactId>             <version>2.3.1</version>         </dependency>         <dependency>             <groupId>com.fasterxml.jackson.core</groupId>             <artifactId>jackson-databind</artifactId>             <version>2.3.3</version>         </dependency>

好了，现在websocket可以正常建立起来了

返回用户未读的消息

当连接建立后，会进入SystemWebSocketHandler的afterConnectionEstablished方法，代码看上边，取出WebSocketHandshakeInterceptor中保存的用户名

查询信息后使用session.sendMessage(new TextMessage(count + ""));返回给用户，从哪来回哪去

服务端推送消息给用户

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

@Controller public class AdminController {       static Logger logger = LoggerFactory.getLogger(AdminController.class);       @Autowired(required = false)     private AdminService adminService;       @Bean     public SystemWebSocketHandler systemWebSocketHandler() {         return new SystemWebSocketHandler();     }         @RequestMapping("/auditing")     @ResponseBody     public String auditing(HttpServletRequest request){         //无关代码都省略了         int unReadNewsCount = adminService.getUnReadNews(username);         systemWebSocketHandler().sendMessageToUser(username, new TextMessage(unReadNewsCount + ""));         return result;     } }

在这里可以使用sendMessageToUser给某个用户推送信息，也可以使用sendMessageToUsers给所有用户推送信息