Java ExcutorService优雅关闭方式解析
关闭时可使用如下代码
publicstaticvoidwaitUntilTerminate(finalExecutorServiceexecutorService,finalinttimeout){
try{
executorService.shutdown();
if(!executorService.awaitTermination(timeout,TimeUnit.SECONDS)){//超时后直接关闭
executorService.shutdownNow();
}
}catch(InterruptedExceptione){//awaitTermination出现中断异常也将触发关闭
executorService.shutdownNow();
}
}
但是实际使用中，可能会出现即使使用了shutdownNow方法，还是无法终止线程的问题，那是因为你的线程无法被中断
shutdownNow方法简单理解就是给在运行的线程发一个中断信号，如果你的线程忽略这个信号，那就无法停下来
举个例子来说明这个问题
publicclassShutDownUtilsTest{
privateExecutorServiceexecutorService;
@Before
publicvoidinit(){
executorService=Executors.newFixedThreadPool(1);
}
@Test
publicvoidshutDownOKTest(){
ShutDownUtils.waitUntilTerminate(executorService,1);
CommonUtils.sleep(1);//等待线程处理中断
Assert.assertTrue(executorService.isTerminated());
}
@Test
publicvoidshutDownNowFailTest(){
executorService.execute(this::canNotStopThread);
ShutDownUtils.waitUntilTerminate(executorService,0);
CommonUtils.sleep(1);//等待线程处理中断
Assert.assertFalse(executorService.isTerminated());
}
@Test
publicvoidshutDownNowOKTest(){
executorService.execute(this::stopThread);
ShutDownUtils.waitUntilTerminate(executorService,0);
CommonUtils.sleep(1);//等待线程处理中断
Assert.assertTrue(executorService.isTerminated());
}
privatevoidcanNotStopThread(){
for(longi=0;i<Long.MAX_VALUE;i++){
}
}
privatevoidstopThread(){
for(longi=0;i<Long.MAX_VALUE&&!Thread.currentThread().isInterrupted();i++){
}
}
}
从上面的测试用例可以看到canNotStopThread无法被shutDownNow终止
然而stopThread可以被正常终止，因为通过Thread.currentThread().isInterrupted()在判断线程是否收到了中断信号
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持毛票票。