如何在Resteasy中关闭ExecutorService

Question

I have a servlet that has an ExecutorService that makes HTTP requests to multiple destinations. I'm not sure how I shutdown the ExecutorService. I don't have destroy() method in Resteasy?

@Path("ops")
public class Dashboard{

ExecutorService threadExecutor = Executors.newCachedThreadPool();

@GET
@Path("data")
@Produces("application/json")
public Response getDataFromDCs(){
  try{
    threadExecutor.invokeAll(jobWorkers, 6000, TimeUnit.SECONDS);
  }catch(Exception e){}
  finally{
  //should call threadExecutor.shutdown() here? 
  }
}
}

Answer 1

You can create a Singleton Class that will have executor Service logic initiated , a destroy method and a service(jobWorker,int time,TimeUnit timeunit). Then write a Listener implementing HTTPServletListener and in contextDestroyed call the destroy method of the singleton class. This will save you from reinitiating executor on each service call and you can safely shutdown the executor on application shutdown. and in the webservice class in getDataFromDCs() get the instance of the singleton class and call it's service method passing the arguments.

Answer 2

you can call shutdown method of the threadExecutor. But it does not guarantee that all the task will finish. You should also use awaitTermination, for example:

while( !executor.awaitTermination(100, TimeUnit.SECONDS) ) {
    LOGGER.info("Awaiting completion of threads.");
}

http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ExecutorService.html#awaitTermination(long,%20java.util.concurrent.TimeUnit)