Question

问题：@ServerEndpoint类中的@Autowired bean为null

如何确保下面的WebSocketController类将注入bean，即如何让它由Spring管理？我可以连接到websocket，所以它可以工作，但是gameService在WebSocketController类实例中总是为null，所以我认为它是由tomcat以某种方式而不是Spring创建的。

我使用Spring启动。我只需要弄清楚如何将bean注入这个websocket控制器类。

WebSocketController类

@Component
@ServerEndpoint("/sock")
public class WebSocketController {

    @Autowired
    private GameService gameService;

    private static Set<Session> clients = Collections.synchronizedSet(new HashSet<Session>());

    @OnMessage
    public void handleMessage(Session session, String message) throws IOException {

        session.getBasicRemote().sendText(
                "Reversed: " + new StringBuilder(message).reverse());
    }

    @OnOpen
    public void onOpen(Session session) {
        clients.add(session);
        System.out.println("New client @"+session.getId());
        if (gameService == null) System.out.println("game service null");
    }

    @OnClose
    public void onClose(Session session) {
        clients.remove(session);
        System.out.println("Client disconnected @" + session.getId());
    }
}

GameService接口和实现

public interface GameService {
    List<Character> getCharacters();
}

@Service
public class GameServiceMockImpl implements GameService {

    @Override
    public List<Character> getCharacters() {
        List<Character> list = new ArrayList<>();
        list.add(new Character("aaa","1.png",100));
        list.add(new Character("aaa","2.jpg",100));
        list.add(new Character("aaa","3.jpg",100));
        return list;
    }
}

申请类

@SpringBootApplication
public class App  {

    public static void main(String args[]){
        SpringApplication.run(App.class,args);
    }

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}

编辑：

使用Spring 4 WebSockets根本不起作用，我甚至无法通过浏览器连接。

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(myHandler(), "/myHandler");
    }

    @Bean
    public WebSocketHandler myHandler() {
        return new MyHandler();
    }

}


public class MyHandler extends TextWebSocketHandler {

    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) {
        System.out.println(message.getPayload());
    }

}

Answer 1

也许这篇文章可以提供帮助：

https://spring.io/blog/2013/05/23/spring-framework-4-0-m1-websocket-support

您可以使用依赖项（使用spring版本＆gt; 4）

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-websocket</artifactId>
    <version>${spring.version}</version>
</dependency>

然后简单地

@ServerEndpoint(value = "/echo", configurator = SpringConfigurator.class)
public class WebSocketEndpoint {

    @Inject
    private BroadcastService broadcaster;

Answer 2

您正在尝试集成Spring和Java WebSocket API。注释为@Component的类被注册到spring bean，其实例由spring管理，但如果类由@ServerEndpoint注释，则它被注册到服务器端WebSocket端点，并且每次都对应端点＆＃39; s WebSocket连接到服务器，其实例由JWA实现创建和管理。我们不能同时使用这两个注释。

您可以使用CDI注入（您的服务器也应该支持）

@ServerEndpoint("/sock")
public class WebSocketController {

    @Inject
    private GameService gameService;

或者查看this doc，Spring 4支持WebSocket

WebSockets JSR 356 Spring集成@ServerEndpoint

2 个答案: