Spring和Websocket相結(jié)合實現(xiàn)消息的推送

更新時間：2016年02月01日 10:19:47 投稿：mrr

這篇文章主要介紹了Spring和Websocket相結(jié)合實現(xiàn)消息的推送的相關(guān)資料，本文介紹的非常詳細(xì)具有參考借鑒價值，感興趣的朋友一起學(xué)習(xí)吧

本文主要有三個步驟

1、用戶登錄后建立websocket連接，默認(rèn)選擇websocket連接，如果瀏覽器不支持，則使用sockjs進行模擬連接
2、建立連接后，服務(wù)端返回該用戶的未讀消息
3、服務(wù)端進行相關(guān)操作后，推送給某一個用戶或者所有用戶新消息相關(guān)環(huán)境 Spring4.0.6(要選擇4.0+),tomcat7.0.55

Websocet服務(wù)端實現(xiàn)

WebSocketConfig.java

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

不要忘記在springmvc的配置文件中配置對此類的自動掃描

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

@Configuration
@EnableWebMvc
@EnableWebSocket

這三個大致意思是使這個類支持以@Bean的方式加載bean，并且支持springmvc和websocket，不是很準(zhǔn)確大致這樣，試了一下@EnableWebMvc不加也沒什么影響，@Configuration本來就支持springmvc的自動掃描

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

用來注冊websocket server實現(xiàn)類，第二個參數(shù)是訪問websocket的地址

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

這個是使用Sockjs的注冊方法

首先SystemWebSocketHandler.java

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){
//查詢未讀消息
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;
}
/**
* 給所有在線用戶發(fā)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();
}
}
}
/**
* 給某個用戶發(fā)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;
}
}
}
}

相關(guān)內(nèi)容大家一看就能明白，就不多解釋了

然后WebSocketHandshakeInterceptor.java

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區(qū)分WebSocketHandler，以便定向發(fā)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) {
}
}

這個的主要作用是取得當(dāng)前請求中的用戶名，并且保存到當(dāng)前的WebSocketHandler中，以便確定WebSocketHandler所對應(yīng)的用戶，具體可參考HttpSessionHandshakeInterceptor

用戶登錄建立websocket連接

index.jsp

<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時要注意

1、這兩個的寫法

<script type="text/javascript" src="http://localhost:8080/Origami/websocket/sockjs-0.3.min.js"></script>
websocket = new SockJS(http://localhost:8080/Origami/sockjs/webSocketServer);

2、web.xml中

<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">

version

web-app_3_1.xsd

這兩個的版本都要是3.0+

然后在這個servlet中加入

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

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

3、添加相關(guān)依賴

<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，現(xiàn)在websocket可以正常建立起來了

返回用戶未讀的消息

當(dāng)連接建立后，會進入SystemWebSocketHandler的afterConnectionEstablished方法，代碼看上邊，取出WebSocketHandshakeInterceptor中保存的用戶名

查詢信息后使用session.sendMessage(new TextMessage(count + ""));返回給用戶，從哪來回哪去

服務(wù)端推送消息給用戶

@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){
//無關(guān)代碼都省略了
int unReadNewsCount = adminService.getUnReadNews(username);
systemWebSocketHandler().sendMessageToUser(username, new TextMessage(unReadNewsCount + ""));
return result;
}
}

在這里可以使用sendMessageToUser給某個用戶推送信息，也可以使用sendMessageToUsers給所有用戶推送信息

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