Spring 3:如何从TaskExecutor调用@Async注释方法

Question

我是Spring的异步任务执行新手,所以如果这听起来像个愚蠢的问题,请原谅我.

我读到@Async注释是从Spring 3.x开始在方法级别引入的,该方法的调用将异步发生.我还读到我们可以在spring配置文件中配置ThreadPoolTask​​Executor.

我无法理解的是,如何从tak执行器调用@Async注释方法让我们假设--AsyncTaskExecutor

早些时候我们曾经做过类似的事情:

@Autowired protected AsyncTaskExecutor executor;

然后

executor.submit(<Some Runnable or Callable task>)

我无法理解@Async注释方法和TaskExecutor之间的关系.

我尝试在互联网上搜索很多但却无法得到任何相关信息.

有人可以为此提供一个例子.

Answer 1

这是一个@Async使用示例:

@Async
void doSomething() {
    // this will be executed asynchronously
}

现在从另一个类调用该方法,它将异步运行.如果你想要一个返回值,请使用aFuture

@Async
Future<String> returnSomething(int i) {
    // this will be executed asynchronously
}

之间的关系@Async,并TaskExecutor是@Async使用了TaskExecutor幕后.来自文档:

默认情况下,在方法上指定@Async时,将使用的执行程序是提供给"注释驱动"元素的执行程序,如上所述.但是,当需要指示在执行给定方法时应该使用除默认值之外的执行程序时,可以使用@Async批注的value属性.

因此,要设置默认执行程序,请将其添加到spring配置中

<task:annotation-driven executor="myExecutor" />

或者使用特定的执行程序进行单次使用尝试

@Async("otherExecutor")

请参阅http://docs.spring.io/spring/docs/3.2.x/spring-framework-reference/html/scheduling.html#scheduling-annotation-support-async

Answer 2

完整示例

1. 配置弹簧

   @Configuration        
   @EnableAsync        
   @ComponentScan("com.async")
   public class AppConfig {
   
       @Bean
       public AsyncManager asyncManger() {
           return new AsyncManager();
       }
   
       @Bean
       public AsyncExecutor asyncExecutor() {
           return new AsyncExecutor();
       }
   }
   

2. 已创建 Executor 类，我已创建 Executor 以便 spring 负责线程管理。

   public class AsyncExecutor extends AsyncConfigurerSupport {
   
       @Override
       public Executor getAsyncExecutor() {
           ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
           executor.setCorePoolSize(2);
           executor.setMaxPoolSize(2);
           executor.setQueueCapacity(500);
           executor.setThreadNamePrefix("Violation-");
           executor.initialize();
           return executor;
       }
   }
   

3. 创建经理。

   public class AsyncManager {
   
       @Autowired
       private AsyncService asyncService;
   
       public void doAsyncTask(){
           try {
               Map<Long, ViolationDetails> violation = asyncService.getViolation();
               if(!org.springframework.util.CollectionUtils.isEmpty(violation)){
                   violation.entrySet().forEach( violationEntry -> {System.out.println(violationEntry.getKey() +"" +violationEntry.getValue());});
               }
               System.out.println("do some async task");
           } catch (Exception e) {
           }
   
       }
   }
   

4. 配置您的服务类。

   @Service
   public class AsyncService {
   
       @Autowired
       private AsyncExecutor asyncExecutor;
   
       @Async
       public Map<Long,ViolationDetails> getViolation() {
           // TODO Auto-generated method stub
           List<Long> list = Arrays.asList(100l,200l,300l,400l,500l,600l,700l);
           Executor executor = asyncExecutor.getAsyncExecutor();
           Map<Long,ViolationDetails>  returnMap = new HashMap<>();
           for(Long estCode : list){
               ViolationDetails violationDetails = new ViolationDetails(estCode);
               returnMap.put(estCode, violationDetails);
               executor.execute((Runnable)new ViolationWorker(violationDetails));
           }
           return returnMap;       
       }
   }
   class ViolationWorker implements Runnable{
   
       private ViolationDetails violationDetails;
   
       public ViolationWorker(ViolationDetails violationDetails){
           this.violationDetails = violationDetails;
       }
   
       @Override
       public void run() {
           violationDetails.setViolation(System.currentTimeMillis());
           System.out.println(violationDetails.getEstablishmentID() + "    " + violationDetails.getViolation());
       }
   }
   

5. 模型。

   public class ViolationDetails {
       private long establishmentID;
       private long violation;
   
   
       public ViolationDetails(long establishmentID){
           this.establishmentID = establishmentID;
       }
   
       public long getEstablishmentID() {
           return establishmentID;
       }
       public void setEstablishmentID(long establishmentID) {
           this.establishmentID = establishmentID;
       }
       public long getViolation() {
           return violation;
       }
       public void setViolation(long violation) {
           this.violation = violation;
       }
   
   }
   

6. 测试运行

   public class AppTest {
       public static void main(String[] args) throws SQLException {
           AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
           ctx.register(AppConfig.class);
           ctx.refresh();
   
           AsyncManager task= ctx.getBean(AsyncManager.class);
           task.doAsyncTask();
       }
   }