如何将Spring Webflux Websocket路由作为注解？

Spring WebFlux是Spring框架提供的响应式编程模型的一部分，它允许我们使用注解来定义WebFlux WebSocket的路由。

要将Spring WebFlux WebSocket路由作为注解，我们可以按照以下步骤进行操作：

首先，我们需要在Spring Boot项目的依赖中添加相关的WebFlux和WebSocket依赖。可以在项目的pom.xml文件中添加如下依赖：

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

创建一个WebSocket处理器类，该类使用@Controller注解标记，并定义WebSocket的处理方法。例如：

import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import import org.springframework.web.reactive.socket.WebSocketSession;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

@RestController
public class MyWebSocketHandler implements WebSocketHandler {

    @Override
    public Mono<Void> handle(WebSocketSession session) {
        Flux<WebSocketMessage> messageFlux = /* 处理WebSocket消息的逻辑 */;
        return session.send(messageFlux);
    }
}

在WebSocket处理器类中，我们可以使用@MessageMapping注解来定义特定消息的处理方法。例如：

import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import import org.springframework.web.reactive.socket.WebSocketSession;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;

@RestController
public class MyWebSocketHandler implements WebSocketHandler {

    @MessageMapping("/hello")
    public Flux<String> handleHelloMessage(WebSocketMessage message) {
        /* 处理收到的WebSocket消息的逻辑 */
        return Flux.just("Hello, " + message.getPayload());
    }

    @Override
    public Mono<Void> handle(WebSocketSession session) {
        Flux<WebSocketMessage> messageFlux = /* 处理WebSocket消息的逻辑 */;
        return session.send(messageFlux);
    }
}

创建一个WebSocket路由配置类，该类使用@Configuration注解标记，并定义WebSocket的路由配置。例如：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.reactive.config.EnableWebFlux;
import org.springframework.web.reactive.config.WebFluxConfigurer;
import org.springframework.web.reactive.handler.SimpleUrlHandlerMapping;
import org.springframework.web.reactive.socket.server.support.WebSocketHandlerAdapter;

@Configuration
@EnableWebFlux
public class WebSocketConfig implements WebFluxConfigurer {

    @Bean
    public WebSocketHandlerAdapter handlerAdapter() {
        return new WebSocketHandlerAdapter();
    }

    @Bean
    public SimpleUrlHandlerMapping handlerMapping(MyWebSocketHandler handler) {
        SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
        mapping.setUrlMap(Collections.singletonMap("/ws", handler));
        mapping.setOrder(1);
        return mapping;
    }
}

在上述配置中，我们创建了一个WebSocketHandlerAdapter和一个SimpleUrlHandlerMapping，并将我们的WebSocket处理器注册到了路由配置中。

现在，我们可以使用@RestController注解标记一个Controller类，并在其中使用@RequestMapping注解来定义WebSocket的路由。例如：

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class WebSocketController {

    @RequestMapping("/ws")
    public String webSocketEndpoint() {
        return "WebSocket Endpoint";
    }
}