java - 计划任务不适用于 websockets

Question

我有一个带有 websockets 的 spring boot 应用程序:

@SpringBootApplication(exclude = {SecurityAutoConfiguration.class})
@EnableScheduling
public class TestApplication {

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

WebSocket 配置:

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry webSocketHandlerRegistry) {
        webSocketHandlerRegistry.addHandler(socketHandler(), "/connect/*")
                .setAllowedOrigins("*")
                .addInterceptors(handshakeInterceptor());
    }

    @Bean
    public WebSocketHandler socketHandler() {
        return new CustomHandler();
    }

    @Bean
    public HandshakeInterceptor handshakeInterceptor() {
        return new CustomInterceptor();
    }    
}

它运行良好。然后我添加了 @EnableSheduled 并创建了 Scheduling 组件:

@Component
public class ScheduledTask {

    @Scheduled(fixedRate = 1000)
    public void printHello() {
        System.out.println("hello");
    }
}

并得到一个异常:

org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'defaultSockJsTaskScheduler' is expected to be of type 'org.springframework.scheduling.TaskScheduler' but was actually of type 'org.springframework.beans.factory.support.NullBean'
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:392) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:224) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1116) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1083) ~[spring-beans-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.resolveSchedulerBean(ScheduledAnnotationBeanPostProcessor.java:313) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.finishRegistration(ScheduledAnnotationBeanPostProcessor.java:254) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.onApplicationEvent(ScheduledAnnotationBeanPostProcessor.java:231) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.scheduling.annotation.ScheduledAnnotationBeanPostProcessor.onApplicationEvent(ScheduledAnnotationBeanPostProcessor.java:103) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:402) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:359) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:896) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.finishRefresh(ServletWebServerApplicationContext.java:163) ~[spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:552) ~[spring-context-5.1.7.RELEASE.jar:5.1.7.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142) ~[spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.5.BUILD-20190515.065035-40.jar:2.1.5.BUILD-SNAPSHOT]
    at ru.test.project.TestApplication.main(TestApplication.java:17) [classes/:na]

我试图从我的项目中删除 websockets。在此之后，一切都开始正常工作。如何解决？

Answer 1

这可以通过手动定义一个 TaskScheduler bean 来解决，例如参见这篇文章:https://medium.com/@jing.xue/spring-boot-application-startup-error-with-websocket-enabled-832456bb2e

因此，在 Java 术语中，这将是

@Bean
public TaskScheduler taskScheduler() {
    TaskScheduler scheduler = new ThreadPoolTaskScheduler();

    scheduler.setPoolSize(2);
    scheduler.setThreadNamePrefix("scheduled-task-");
    scheduler.setDaemon(true);

    return scheduler;
}