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• 前言
  • 一、建項目
    • • 1. 在父項目ams-cloud下建立maven子項目ams-websocket
      • 2.pom文件添加常用依賴，另外添加redis依賴等，我這裡直接引用common模塊
      • 3.添加bootstrap.yml文件
      • 4.創建application
  • 二、添加config類、攔截器類、處理器類等
    • • 1.添加config類
      • 2.添加攔截器類
      • 3.添加處理器類
  • 三、添加controller
    • • 1.controller如下：
        • 2.運行結果

前言

一、建項目

1. 在父項目ams-cloud下建立maven子項目ams-websocket

2.pom文件添加常用依賴，另外添加redis依賴等，我這裡直接引用common模塊

    <dependencies>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>

        <dependency>
            <groupId>com.ams</groupId>
            <artifactId>ams-common</artifactId>
            <version>${ams.version}</version>
        </dependency>

    </dependencies>

3.添加bootstrap.yml文件

server:
  port: 21000

spring:
  application:
    name: ams-websocket
  cloud:
    nacos:
      # 註冊中心
      discovery:
        server-addr: http://192.168.132.129:8848
      # 配置中心
      config:
        server-addr: ${spring.cloud.nacos.discovery.server-addr}
        file-extension: yaml
        shared-configs[0]:
          data-id: ams-common.yaml
          refresh: true
          
logging:
  level:
    spring.: DEBUG

4.創建application

@EnableDiscoveryClient
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@ComponentScan("com.ams")
public class WebsocketApp {
    public static void main(String[] args) {
        SpringApplication.run(WebsocketApp.class,args);
    }
}

二、添加config類、攔截器類、處理器類等

1.添加config類

@Configuration
@EnableWebSocket
public class WebsocketConfig implements WebSocketConfigurer {

    @Autowired
    private RedisUtils redisUtils;

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        // 註冊websocket組件 添加處理器和攔截器
        // websocket是websocket伺服器的請求路徑可以自己定義
        registry.addHandler(new WebsocketHandler(redisUtils),"/websocket")
                //指定自定義攔截器
                .addInterceptors(new WebsocketInterceptor(redisUtils))
                //允許跨域
                .setAllowedOrigins("*");

        //在某些低版本的瀏覽器中不支持websocket可以用sock-js替代
        registry.addHandler(new WebsocketHandler(redisUtils),"/sock-js")
                // 指定自定義攔截器
                .addInterceptors(new WebsocketInterceptor(redisUtils))
                // 允許跨域
                .setAllowedOrigins("*")
                // 開啟sockJs支持
                .withSockJS();

    }

}

2.添加攔截器類

@Slf4j
public class WebsocketInterceptor extends HttpSessionHandshakeInterceptor  {

    private final RedisUtils redisUtils;
    public WebsocketInterceptor(RedisUtils redisUtils){
        this.redisUtils=redisUtils;
    }
    
	/** 管理握手過程，存入用戶信息 */
    @Override
    public boolean beforeHandshake(ServerHttpRequest request,
                                   ServerHttpResponse response,
                                   WebSocketHandler handler,
                                   Map<String, Object> map) throws Exception {
        String header_key = "Sec-WebSocket-Protocol";
        HttpHeaders headers = request.getHeaders();
        String token = headers.getFirst(header_key);
        log.info("token = [{}]", token);
        HttpHeaders responseHeaders = response.getHeaders();
        UserAuthDTO userAuthDTO = getUserInfo(token);
        if(userAuthDTO == null){
            log.error("socket連接失敗 ---> token過期 ---> [{}]", token);
            response.setStatusCode(HttpStatus.NETWORK_AUTHENTICATION_REQUIRED);
            return false;
        }
        map.put("userAuthDTO",userAuthDTO);
        responseHeaders.add(header_key,token);
        return super.beforeHandshake(request, response, handler, map);

    }

    /** 通過redis讀取用戶信息 **/
    public UserAuthDTO getUserInfo(String token) {
        String key = token;
        if(StrUtil.isEmpty(key)){
            return null;
        }
        UserAuthDTO userAuthDTO = (UserAuthDTO) redisUtils.get(key);
        if(userAuthDTO==null){
            log.error("redis用戶信息空 ---> 登錄過期/token不正確");
            return null;
        }
        return userAuthDTO;
    }
}

3.添加處理器類

@Slf4j
public class WebsocketHandler extends AbstractWebSocketHandler  {

    //定義全局變數用於保存所有用戶的會話
    /** 系統管理員 **/
    public static final Map<String, WebSocketSession> SYSUSER_SOCKETS = new HashMap<>();

    private static RedisUtils redisUtils;
    public WebsocketHandler(RedisUtils redisUtils){
        WebsocketHandler.redisUtils = redisUtils;
    }

    /**
     * webSocket連接創建後調用
     */
    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        Map<String, Object> attrMap = session.getAttributes();
        UserAuthDTO userAuthDTO = (UserAuthDTO) attrMap.get("userAuthDTO");
        SYSUSER_SOCKETS.put(userAuthDTO.getUserId().toString(),session);
        log.info("管理員[{}]連接成功，當前線上人數[{}]", userAuthDTO.getUsername(), SYSUSER_SOCKETS.size());
    }

    /**
     * 接收到消息會調用
     */
    @Override
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        try {
       		log.info("收到客戶端消息[{}]", message);
            if(session.isOpen()){
                session.sendMessage(message);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 連接關閉會調用
     */
    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        log.info("客戶端關閉連接....");
        Map<String, Object> attrMap = session.getAttributes();
        // 刪除緩存
        deleteSocket(attrMap);
        // 關閉連接
        session.close();
        log.info("已關閉socket連接");
    }

    /**
     * 刪除socket緩存
     */
    public static void deleteSocket(Map<String, Object> attr) {
        UserAuthDTO userAuthDTO = (UserAuthDTO) attr.get("userAuthDTO");
        if (!SYSUSER_SOCKETS.isEmpty()) {
            SYSUSER_SOCKETS.remove(userAuthDTO.getUserId().toString());
            log.info("管理員[{}]關閉連接了，當前線上人數[{}]", userAuthDTO.getUsername(), SYSUSER_SOCKETS.size());
        }
    }

    /**
     * 連接出錯會調用
     */
    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        log.error("socket連接出錯...");
        exception.printStackTrace();
        Map<String, Object> attrMap = session.getAttributes();
        //刪除緩存
        deleteSocket(attrMap);
        // 關閉連接
        session.close();
        log.error("已關閉socket連接");
    }
}

三、添加controller

1.controller如下：

@RestController
@RequestMapping("/websocket")
@Slf4j
@RequiredArgsConstructor
public class WebsocketController {

    /** 獲取線上管理用戶 */
    @GetMapping(value = "getLoginSysUser")
    public R<List<UserAuthDTO>> getLoginSysUser(){
        Map<String, WebSocketSession> userMap = WebsocketHandler.SYSUSER_SOCKETS;
        List<UserAuthDTO> list = new ArrayList<>();
        userMap.forEach((k,v)->{
            Map<String, Object> attrMap = v.getAttributes();
            UserAuthDTO userAuthDTO = (UserAuthDTO) attrMap.get("userAuthDTO");
            list.add(userAuthDTO);
        });
        return R.ok(list);
    }
    
}

2.運行結果

2022-03-04 16:58:56.822  INFO 15272 --- [nio-21000-exec-2] c.c.f.m.w.config.WebsocketInterceptor    : token = [83868c09-a744-4a7a-a16e-24dc3d7e8cdc]
2022-03-04 16:58:59.335  INFO 15272 --- [nio-21000-exec-2] c.c.f.m.w.handler.WebsocketHandler       : 管理員[admin]連接成功，當前線上人數[1]