計划任務不適用於 websockets

Question

我有一個帶有 websockets 的 Spring Boot 應用程序：

@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();
    }    
}

它工作得很好。 然后我添加了@EnableSheduled並創建了 Scheduling 組件：

@Component
public class ScheduledTask {

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

並得到一個例外：

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]

我試圖從我的項目中刪除 websockets。 在此之后，一切都開始正常工作。 如何解決？

Answer 1

這可以通過手動定義TaskScheduler bean 來解決，例如參見這篇文章： https : //medium.com/@jing.xue/spring-boot-application-startup-error-with-websocket-enabled-832456bb2e

所以，在 Java 術語中，這將是

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

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

    return scheduler;
}

Answer 2

除了米歇爾接受的答案：

使用 Spring Boot 時，與其直接創建 TaskScheduler，不如為其使用構建器：

@Bean
public ThreadPoolTaskScheduler taskScheduler(TaskSchedulerBuilder builder) {
    return builder.build();
}

構建器在org.springframework.boot.autoconfigure.task.TaskSchedulingAutoConfiguration定義。 因此，使用這種方法，您將獲得與不使用 @EnableWebSocket 完全相同的調度程序（即它將使用來自 spring 配置屬性等的池大小）。

Answer 3

有一個更方便的方法來解決這個問題。 您可以使用@Configurable和@EnableScheduling注釋自定義調度程序類，並在其中實現SchedulingConfigurer接口。 然后你應該實現configureTasks方法，它有一個ScheduledTaskRegistrar對象作為它的輸入參數。 使用此對象，您可以定義和執行任何類型的計划任務。 請記住，您需要在父 Bean 中通知 Spring Framework Context 相關信息。

父 Bean 類的構造函數：

public ParentBean() {
        new AnnotationConfigApplicationContext(MyTaskScheduler.class);
}

MyTaskScheduler 類：

@Configurable
@EnableScheduling
public class MyTaskScheduler implements SchedulingConfigurer {
    @Override
    public void configureTasks (ScheduledTaskRegistrar taskRegistrar) {
        // -- Schedule task #1  --
        taskRegistrar.addFixedDelayTask(() -> { firstTask(); }, 10000);

        // -- Schedule task #2 --
        taskRegistrar.addFixedRateTask(() -> { secondTask(); }, 1000);
    }

    private void firstTask() {
        // -- Your first task logic goes here! --
    }

    private void secondTask() {
        // -- Your second task logic goes here! --
    }
}