Spring集成websocket抛出“'outputChannel'或'outputChannelName'是必需的”异常

Question

我是 Spring 集成框架的新手。 在运行 spring 集成 websocket 示例 code 我得到 需要“outputChannel”或“outputChannelName”例外。

我错过了什么吗？

以下是我的代码，

@Configuration
@ComponentScan
@EnableAutoConfiguration
@RestController
public class Application {

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

    @Bean
    ServerWebSocketContainer serverWebSocketContainer() {
        return new ServerWebSocketContainer("/names").withSockJs();
    }

    @Bean
    MessageHandler webSocketOutboundAdapter() {
        return new WebSocketOutboundMessageHandler(serverWebSocketContainer());
    }

    @Bean(name = "webSocketFlow.input")
    MessageChannel requestChannel() {
        return new DirectChannel();
    }

    @Bean
    IntegrationFlow webSocketFlow() {
        return f -> {
            Function<Message, Object> splitter = m -> serverWebSocketContainer().getSessions().keySet().stream()
                    .map(s -> MessageBuilder.fromMessage(m).setHeader(SimpMessageHeaderAccessor.SESSION_ID_HEADER, s).build()).collect(Collectors.toList());
            f.split(Message.class, splitter).channel(c -> c.executor(Executors.newCachedThreadPool())).handle(webSocketOutboundAdapter());
        };
    }

    @RequestMapping("/hi/{name}")
    public void send(@PathVariable String name) {
        requestChannel().send(MessageBuilder.withPayload(name).build());
    }
}

异常堆栈，

java.lang.IllegalStateException: 'outputChannel' or 'outputChannelName' is required
    at org.springframework.util.Assert.state(Assert.java:70)
    at org.springframework.integration.endpoint.MessageProducerSupport.afterSingletonsInstantiated(MessageProducerSupport.java:153)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:781)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867)

Answer 1

java.lang.IllegalStateException: 'outputChannel' or 'outputChannelName' is required
at org.springframework.util.Assert.state(Assert.java:70)
at org.springframework.integration.endpoint.MessageProducerSupport.afterSingletonsInstantiated(MessageProducerSupport.java:153)

注意 - MessageProducerSupport。您的代码没有显示任何类型的内容，因此您只是在您的应用程序中向我们隐藏了一些内容。

我猜你可能有类似的东西：

@Bean
public WebSocketInboundChannelAdapter webSocketInboundChannelAdapter() {
    ...
}

而正是这个必须用setOutputChannel() 声明。

或者，如果您使用它作为 Java DSL 的起点 - IntegrationFlows.from(webSocketInboundChannelAdapter())，则不要使用 @Bean 声明它。框架会在之后为您处理正确的配置和注册。