超时后如何取消任务？

本文介绍了超时后如何取消任务？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一些 Task 执行可能会挂起的I / O阻止操作（从 URL 获取文件）

I have some Task execute a I/O blocking operation that can hang (fetching a file from an URL)

task = new Task<List<WSDLOperation>>() { @Override protected List<WSDLOperation> call() { List<WSDLOperation> services = new ArrayList<>(); try { services = WSDLService.createService(wsdlURL).getOperations(); } catch (Exception ex) { LOG.log(Level.WARNING, "Can't reach {0}", wsdlURL); } return services; } }; }

方法 createService 可以永远等待，而不会抛出任何 Exception 。 （我使用Main类中定义的全局（静态公共） ExecutorService 执行任务）。

The method createService can wait forever without throwing any Exception. (I execute the task using a global (static public)ExecutorService defined in Main class).

推荐答案

如何在超时后使用Future和取消任务：

How use future and cancel task after timeout:

import java.util.concurrent.Callable; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import java.util.concurrent.TimeUnit; import java.util.concurrent.TimeoutException; public class Test { public static void main(String[] args) throws Exception { ExecutorService executor = Executors.newSingleThreadExecutor(); Task t = new Task(); Future<String> future = executor.submit(t); try { System.out.println("Started.."); System.out.println(future.get(5, TimeUnit.SECONDS)); // throws // TimeoutException System.out.println("Finished!"); } catch (TimeoutException e) { future.cancel(true); System.out.println("Terminated!"); } } } class Task implements Callable<String> { @Override public String call() throws Exception { for (int i = 0; i < 1000; i++) { Thread.sleep(1000); System.out.println("task running!"); } return "Ready!"; } }