[后端] webSocket demo跑通

backend/microservice-provider-access-8002/pom.xml

@@ -103,6 +103,12 @@
             <groupId>com.squareup.okhttp3</groupId>
             <artifactId>okhttp</artifactId>
         </dependency>
+
+        <!-- WebSocket -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-websocket</artifactId>
+        </dependency>
     </dependencies>
 
 

backend/microservice-provider-access-8002/src/main/java/com/cxyxiaomo/epp/access/config/WebSocketConfig.java

@@ -0,0 +1,28 @@
+package com.cxyxiaomo.epp.access.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;
+
+/**
+ * 开启WebSocket支持
+ */
+@Configuration
+public class WebSocketConfig implements ServletContextInitializer {
+    /**
+     * 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 {
+
+    }
+}

backend/microservice-provider-access-8002/src/main/java/com/cxyxiaomo/epp/access/controller/WebSocketServer.java

@@ -0,0 +1,112 @@
+package com.cxyxiaomo.epp.access.controller;
+
+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;
+
+@ServerEndpoint("/websocket/{userId}")
+@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 = "userId") 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);
+            }
+        }
+    }
+}

backend/microservice-provider-access-8002/src/main/java/com/cxyxiaomo/epp/access/pojo/WebSocketData.java

@@ -0,0 +1,19 @@
+package com.cxyxiaomo.epp.access.pojo;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.experimental.Accessors;
+
+@Data
+@NoArgsConstructor
+@Accessors(chain = true) // 链式写法
+public class WebSocketData {
+    // 小程序: "miniprogram"  门禁: "guard"
+    private String type;
+
+    // 需要执行的动作
+    private String action;
+
+    // 传输的数据（JSON字符串）
+    private String json;
+}

backend/pom.xml

@@ -127,6 +127,13 @@
                 <version>4.10.0</version>
             </dependency>
 
+            <!-- WebSocket -->
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-starter-websocket</artifactId>
+                <version>2.7.6</version>
+            </dependency>
+
             <!-- Fastjson -->
             <dependency>
                 <groupId>com.alibaba.fastjson2</groupId>