升級到Spring Boot後@Async不工作1.3.3

Question

我有一個在Spring Boot 1.2.3下運行的應用程序，它使用的方法註解爲@Async。迄今爲止它一直在正常工作。

升級到Spring Boot 1.3.3後，標記爲@Async的方法不會在單獨的線程中調用。

下面是說明了問題的一個範例程序：

App.java：

package test; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.beans.factory.annotation.Autowired; 
import org.springframework.boot.CommandLineRunner; 
import org.springframework.boot.SpringApplication; 
import org.springframework.boot.autoconfigure.EnableAutoConfiguration; 
import org.springframework.context.annotation.ComponentScan; 
import org.springframework.context.annotation.Configuration; 
import org.springframework.scheduling.annotation.EnableAsync; 


@Configuration 
@EnableAutoConfiguration 
@ComponentScan(basePackages = { "test" }) 
@EnableAsync 
public class App implements CommandLineRunner { 

    private static final Logger log = LoggerFactory.getLogger(App.class); 

    @Autowired 
    AsyncClass async; 

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

    public void run(String... arg0) throws Exception { 
     log.info("in run"); 
     async.start(); 
     log.info("done run"); 
    } 

} 

AsyncClass.java：

package test; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.context.annotation.Bean; 
import org.springframework.scheduling.annotation.Async; 
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor; 
import org.springframework.stereotype.Component; 


@Component 
public class AsyncClass { 

    private static final Logger log = LoggerFactory.getLogger(AsyncClass.class); 

    @Async("myTaskExecutor") 
    public void start() { 
     log.info("in async task"); 
     try { 
      Thread.sleep(2000); 
     } catch (InterruptedException e) { } 
     log.info("done async task"); 
    } 

    @Bean 
    public ThreadPoolTaskExecutor myTaskExecutor() { 

     ThreadPoolTaskExecutor bean = new ThreadPoolTaskExecutor(); 
     bean.setCorePoolSize(1); 
     bean.setMaxPoolSize(1); 
     bean.setQueueCapacity(10); 
     bean.setThreadPriority(1); 
     bean.setWaitForTasksToCompleteOnShutdown(true); 
     return bean; 
    } 

} 

的pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 
    <modelVersion>4.0.0</modelVersion> 
    <groupId>dbush</groupId> 
    <artifactId>async-test</artifactId> 
    <version>0.0.1-SNAPSHOT</version> 
    <name>async-test</name> 

    <properties> 
     <java.version>1.8</java.version> 
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
     <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 
     <maven.compiler.source>${java.version}</maven.compiler.source> 
     <maven.compiler.target>${java.version}</maven.compiler.target>  
    </properties> 

    <parent> 
     <groupId>org.springframework.boot</groupId> 
     <artifactId>spring-boot-starter-parent</artifactId> 
     <!-- this is the only line that differs --> 
     <version>1.3.3.RELEASE</version> 
    </parent> 

    <dependencies> 
     <dependency> 
      <groupId>org.springframework.boot</groupId> 
      <artifactId>spring-boot-starter-web</artifactId> 
      <exclusions> 
       <exclusion> 
        <groupId>org.slf4j</groupId> 
        <artifactId>log4j-over-slf4j</artifactId> 
       </exclusion> 
      </exclusions> 
     </dependency> 
    </dependencies> 

</project> 

在1.2.3下，日誌start方法中的語句顯示它們在線程myTaskExecutor-1中運行。在1.3.3下，相同的日誌顯示它們在線程main中運行。

任何想法可能是錯誤的嗎？

Answer 1

您需要將您的bean工廠方法放在註釋爲@Configuration的其他類中。 Executor將以這種方式用於@Async方法的執行。

@Configuration 
@EnableAsync 
public class AsyncConfig { 
    @Bean(name = "myTaskExecutor") 
    public ThreadPoolTaskExecutor myTaskExecutor() { 
     return new ThreadPoolTaskExecutor(); 
    } 
} 

Answer 2

注入配置類可能是一個挑戰，我不會推薦它，特別是如果該類也是一個實際的bean。恕我直言，你的班級確實太多了。接下來移動它所屬的ThreadPoolTaskExecutor的配置。

而不是自動裝配創建一個@Bean方法，它將返回CommandLineRunner而不是您實現它。

@SpringBootApplication 
@EnableAsync 
public class App { 

    private static final Logger log = LoggerFactory.getLogger(App.class); 

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

    @Bean 
    public CommandLineRunner runner(AsyncClass async) { 

     return new CommandLineRunner() { 
     public void run(String... arg0) throws Exception { 
      log.info("in run"); 
      async.start(); 
      log.info("done run"); 
     }  
     }; 

    } 

    @Bean 
    public ThreadPoolTaskExecutor taskExecutor() { 

     ThreadPoolTaskExecutor bean = new ThreadPoolTaskExecutor(); 
     bean.setCorePoolSize(1); 
     bean.setMaxPoolSize(1); 
     bean.setQueueCapacity(10); 
     bean.setThreadPriority(1); 
     bean.setWaitForTasksToCompleteOnShutdown(true); 
     return bean; 
    } 
} 

然後清理你的AsyncClass。