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<!-- springboot依赖maven仓库版本 --> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.2.5.RELEASE</version> </parent> <!-- SpringBoot通用依赖模块 --> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter</artifactId> </dependency> <!-- --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <!--排除tomcat依赖: 准备替换undertow部署--> <exclusion> <artifactId>spring-boot-starter-tomcat</artifactId> <groupId>org.springframework.boot</groupId> </exclusion> </exclusions> </dependency> <!--undertow容器,替换springboot内置容器tomcat--> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-undertow</artifactId> </dependency> <!--springboot WebSocket --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-websocket</artifactId> </dependency> <dependencies>
因为一般的请求都是HTTP请求(单向通信),HTTP是一个短连接(非持久化),且通信只能由客户端发起,HTTP协议做不到服务器主动向客户端推送消息。举个例子:前后端交互就是前端发送请求,从后端拿到数据后展示到页面,如果前端没有主动请求接口,那后端就不能发送数据给前端。然而,WebSocket确能很好的解决这个问题,服务端可以主动向客户端推送消息,客户端也可以主动向服务端发送消息,实现了服务端和客户端真正的平等。
package com.chengfu.config; import org.springframework.boot.web.servlet.ServletContextInitializer; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.socket.server.standard.ServerEndpointExporter; import javax.servlet.ServletContext; import javax.servlet.ServletException; @Configuration public class WebSocketConfig implements ServletContextInitializer { // 原文链接:https://blog.csdn.net/weixin_44185837/article/details/124942482 /** * 这个bean的注册,用于扫描带有@ServerEndpoint的注解成为websocket,如果你使用外置的tomcat就不需要该配置文件 */ @Bean public ServerEndpointExporter serverEndpointExporter() { return new ServerEndpointExporter(); } @Override public void onStartup(ServletContext servletContext) throws ServletException { } }
package com.chengfu.socket; import lombok.extern.slf4j.Slf4j; import org.springframework.stereotype.Component; import javax.websocket.*; import javax.websocket.server.PathParam; import javax.websocket.server.ServerEndpoint; import java.io.IOException; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.CopyOnWriteArraySet; /** * websocket服务端,接收websocket客户端长连接 */ @ServerEndpoint("/websocket/api1/{id}") @Component @Slf4j public class WebSocketServer { // 与某个客户端的连接会话,需要通过它来给客户端发送数据 private Session session; // session集合,存放对应的session private static ConcurrentHashMap<Integer, Session> sessionPool = new ConcurrentHashMap<>(); // concurrent包的线程安全Set,用来存放每个客户端对应的WebSocket对象。 private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<>(); /** * 建立WebSocket连接 * * @param session * @param userId 用户ID */ @OnOpen public void onOpen(Session session, @PathParam(value = "id") Integer userId) { log.info("WebSocket建立连接中,连接用户ID:{}", userId); try { Session historySession = sessionPool.get(userId); // historySession不为空,说明已经有人登陆账号,应该删除登陆的WebSocket对象 if (historySession != null) { webSocketSet.remove(historySession); historySession.close(); } } catch (IOException e) { log.error("重复登录异常,错误信息:" + e.getMessage(), e); } // 建立连接 this.session = session; webSocketSet.add(this); sessionPool.put(userId, session); log.info("建立连接完成,当前在线人数为:{}", webSocketSet.size()); } /** * 发生错误 * * @param throwable e */ @OnError public void onError(Throwable throwable) { throwable.printStackTrace(); } /** * 连接关闭 */ @OnClose public void onClose() { webSocketSet.remove(this); log.info("连接断开,当前在线人数为:{}", webSocketSet.size()); } /** * 接收客户端消息 * * @param message 接收的消息 */ @OnMessage public void onMessage(String message) { log.info("收到客户端发来的消息:{}", message); } /** * 推送消息到指定用户 * * @param userId 用户ID * @param message 发送的消息 */ public static void sendMessageByUser(Integer userId, String message) { log.info("用户ID:" + userId + ",推送内容:" + message); Session session = sessionPool.get(userId); try { session.getBasicRemote().sendText(message); } catch (IOException e) { log.error("推送消息到指定用户发生错误:" + e.getMessage(), e); } } /** * 群发消息 * * @param message 发送的消息 */ public static void sendAllMessage(String message) { log.info("发送消息:{}", message); for (WebSocketServer webSocket : webSocketSet) { try { webSocket.session.getBasicRemote().sendText(message); } catch (IOException e) { log.error("群发消息发生错误:" + e.getMessage(), e); } } } }
找了一些资料没发现springboot有处理@ServerEndpoint注解的websocket请求,但是可以使用servlet容器技术来实现ws请求的过滤。ws请求的拦截可以通过配置方式二来实现,详见下。
package com.chengfu.config; import org.apache.commons.lang3.StringUtils; import org.springframework.stereotype.Component; import javax.servlet.*; import javax.servlet.http.HttpServletRequest; import java.io.IOException; import java.util.Arrays; /** * servlet级别请求过滤 */ @Component public class WebSocketFilterConfig implements Filter { // websocket请求过滤清单 private static final String[] FILTER_LIST = {"/websocket/api1/"}; @Override public void init(FilterConfig filterConfig) throws ServletException { Filter.super.init(filterConfig); } @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException { HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest; String servletPath = httpServletRequest.getServletPath(); // anyMatch: 有一个条件满足就返回true boolean match = Arrays.stream(FILTER_LIST).anyMatch(servletPath::startsWith); // boolean match = Arrays.stream(FILTER_LIST).anyMatch(filterUrl -> servletPath.startsWith(filterUrl)); // 符合ws请求的url开始校验,其他请求一概放过 if (match) { String token = httpServletRequest.getHeader("token"); if (StringUtils.isNotBlank(token)) { filterChain.doFilter(servletRequest, servletResponse); } // else { // JSONObject result = new JSONObject(); // HttpServletResponse httpServletResponse = (HttpServletResponse) servletResponse; // httpServletResponse.setContentType("application/json;charset=utf-8"); // httpServletResponse.setCharacterEncoding("utf-8"); // PrintWriter writer = httpServletResponse.getWriter(); // writer.write(result.toJSONString()); // writer.flush(); // writer.close(); // } } else { // 不包含过滤清单,直接放过请求 filterChain.doFilter(servletRequest, servletResponse); } } @Override public void destroy() { Filter.super.destroy(); } }
连接成功!
package com.chengfu.config; import com.chengfu.interceptor.WebSocketAuthInterceptor; import com.chengfu.socket.WebSocketServer2; import org.springframework.context.annotation.Configuration; import org.springframework.web.socket.config.annotation.EnableWebSocket; import org.springframework.web.socket.config.annotation.WebSocketConfigurer; import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry; // 启用配置 @Configuration // 启用websocket服务端 @EnableWebSocket public class WebSocketConfig2 implements WebSocketConfigurer { // 原文链接:https://blog.csdn.net/weixin_44185837/article/details/124942482 // 实现自: WebSocketConfigurer // 注册websocket拦截器 @Override public void registerWebSocketHandlers(WebSocketHandlerRegistry webSocketHandlerRegistry) { webSocketHandlerRegistry // 只有符合"/websocket/api2/**", "/websocket/api3/**"的请求url,才能进入WebSocketServer2的服务端连接进行数据处理 .addHandler(new WebSocketServer2(), "/websocket/api2/**", "/websocket/api3/**") // WebSocketServer2的握手拦截器处理:尽量避免被无用的请求攻击,在建立连接的时候通过检查授权成功之后才能进行访问 .addInterceptors(new WebSocketAuthInterceptor()) // 允许跨域访问 .setAllowedOrigins("*"); } }
package com.chengfu.interceptor; import lombok.extern.slf4j.Slf4j; import org.apache.commons.lang3.StringUtils; import org.springframework.http.HttpHeaders; import org.springframework.http.server.ServerHttpRequest; import org.springframework.http.server.ServerHttpResponse; import org.springframework.stereotype.Component; import org.springframework.web.socket.WebSocketHandler; import org.springframework.web.socket.server.HandshakeInterceptor; import java.util.List; import java.util.Map; /** * websocket握手拦截 */ @Component @Slf4j public class WebSocketAuthInterceptor implements HandshakeInterceptor { /** * 返回true允许直接通过,返回false拒绝连接 * * @param serverHttpRequest * @param serverHttpResponse * @param webSocketHandler * @param map * @return * @throws Exception */ @Override public boolean beforeHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception { log.error("握手开始!"); // 确保授权正确才能进行websocket连接 HttpHeaders headers = serverHttpRequest.getHeaders(); List<String> header = headers.get("token"); if (header == null || header.size() == 0) { return false; } String token = header.get(0); if (StringUtils.isBlank(token)) { return false; } // TODO: token do something log.error("握手token:{}", token); return true; } @Override public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) { log.error("握手结束"); } }
package com.chengfu.socket; import lombok.extern.slf4j.Slf4j; import org.springframework.http.HttpHeaders; import org.springframework.stereotype.Component; import org.springframework.web.socket.CloseStatus; import org.springframework.web.socket.TextMessage; import org.springframework.web.socket.WebSocketSession; import org.springframework.web.socket.handler.TextWebSocketHandler; import java.io.IOException; import java.time.LocalDateTime; import java.util.concurrent.ConcurrentHashMap; // 配合webSocketConfig2使用 @Component @Slf4j public class WebSocketServer2 extends TextWebSocketHandler { /** * socket 建立成功事件 @OnOpen * * @param session * @throws Exception */ @Override public void afterConnectionEstablished(WebSocketSession session) throws Exception { // websocket入参 // ===============从url上面获取参数 String rawPath = session.getUri().getRawPath(); // String rawQuery = session.getUri().getRawQuery();// 从url上面获取参数 String query = session.getUri().getQuery(); // 从url上面获取参数 // ================= // ================从header上面获取参数 HttpHeaders headers = session.getHandshakeHeaders(); // 从header上获取参数 // ================ String token = headers.get("token").get(0); if (token != null) { WebSocketSession s = WebSessionManager.get(token); if (s != null) { // 当前用户之前已经建立连接,关闭 WebSessionManager.remove(token); } // 重新建立session WebSessionManager.add(token, session); log.error("建立websocket连接:{}", token); } } /** * 接收消息事件 @OnMessage * * @param session * @param message * @throws Exception */ @Override protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception { // 获得客户端传来的消息 String payload = message.getPayload(); System.out.println("server 接收到发送的消息 " + payload); // 服务端发送回去 session.sendMessage(new TextMessage("server 发送消息 " + payload + " " + LocalDateTime.now())); } /** * socket 断开连接时 @OnClose * * @param session * @param status * @throws Exception */ @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { Object token = session.getAttributes().get("token"); if (token != null) { // 用户退出,移除缓存 WebSessionManager.remove(token.toString()); } } } // 来源:https://www.cnblogs.com/meow-world/articles/16283492.html // websocket的session管理器 class WebSessionManager { /** * 保存连接 session 的地方 */ private static final ConcurrentHashMap<String, WebSocketSession> SESSION_POOL = new ConcurrentHashMap<>(); /** * 添加 session * * @param key */ public static void add(String key, WebSocketSession session) { // 添加 session SESSION_POOL.put(key, session); } /** * 删除 session,会返回删除的 session * * @param key * @return */ public static WebSocketSession remove(String key) { // 删除 session return SESSION_POOL.remove(key); } /** * 删除并同步关闭连接 * * @param key */ public static void removeAndClose(String key) { WebSocketSession session = remove(key); if (session != null) { try { // 关闭连接 session.close(); } catch (IOException e) { // todo: 关闭出现异常处理 e.printStackTrace(); } } } /** * 获得 session * * @param key * @return */ public static WebSocketSession get(String key) { // 获得 session return SESSION_POOL.get(key); } }
注!
1. postman版本要升级到10以上,我这里测试版本为v10.17.1;
2. Ctrl+N,打开创建请求的小窗,选择WebSocket;
postman请求地址:
建立websocket连接之前,先进行握手处理,检查headers参数之后,如果符合要求,开始建立连接。
拦截发现headers没有token标识,拒绝客户端连接请求,请求头添加token后,重新请求:
检测到token之后,成功建立连接:
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