java @Asynchronous方法:不运行异步

Question

我尝试让异步进程运行.基于此示例:http://tomee.apache.org/examples-trunk/async-methods/README.html

但是addWorkflow(Workflow workflow)只有当代码run(Workflow workflow)完全完成时,该方法才会返回.

然后当它返回并被result.get();调用时,我将获得异常:

引起:java.lang.IllegalStateException:Object不代表一个真实的Future

有什么建议我缺少什么？

@Singleton
public class WorkflowProcessor {

@EJB
private  WorkflowManager workflowManager;

private final static Logger log = Logger.getLogger(WorkflowProcessor.class.getName());



public void runWorkflows(Collection<Workflow> workflows) throws Exception{  
    final long start = System.nanoTime();
    final long numberOfWorkflows = workflows.size();
    Collection<Future<Workflow>> asyncWorkflows = new ArrayList<>();

    for(Workflow workflow : workflows){
        Future<Workflow> w = addWorkflow(workflow);
        asyncWorkflows.add(w);
    }    
    log.log(Level.INFO, "workflow jobs added {0}", new Object[]{numberOfWorkflows});
    for(Future<Workflow> result : asyncWorkflows){
       result.get();
    }

    final long total = TimeUnit.NANOSECONDS.toSeconds(System.nanoTime() - start);
    log.log(Level.INFO, "WorkflowProcessor->runWorkflows {0} workflows completed in:{1}", new Object[]{numberOfWorkflows, total});

}

@Asynchronous
@Lock(LockType.READ)
@AccessTimeout(-1)
private Future<Workflow> addWorkflow(Workflow workflow){

    run(workflow);

    return new AsyncResult<Workflow>(workflow);                
}


private void run(Workflow workflow){
    this.workflowManager.runWorkflow(workflow);
}

Answer 1

所以通常的方法是在调用方法的另一个bean中使用@Asynchronous方法.

@Stateless
public class ComputationProcessor {

 @Asynchronous
 public Future<Data> performComputation {
   return new AsyncResult<Data>(null);
 }
}

@Stateless
public class ComputationService {

 @Inject
 private ComputationProcessor mProcessor;

 public void ...() {
   Future<Data> result = mProcessor.performComputation();
   ...
 }
}

正如您所发现的,如果@Asynchronous方法与调用者位于同一个bean中,它将无法工作.