如何在Java中设置定时器？

Question

如何在Java中设置定时器？

如何设置一个定时器，例如2分钟，尝试连接到数据库，然后在连接中出现任何问题时抛出异常？

Answer 1

用这个long&nbsp;startTime&nbsp;=&nbsp;System.currentTimeMillis();long&nbsp;elapsedTime&nbsp;=&nbsp;0L.while&nbsp;(elapsedTime&nbsp;<&nbsp;2*60*1000)&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;//perform&nbsp;db&nbsp;poll/check &nbsp;&nbsp;&nbsp;&nbsp;elapsedTime&nbsp;=&nbsp;(new&nbsp;Date()).getTime()&nbsp;-&nbsp;startTime;}//Throw&nbsp;your&nbsp;exception

Answer 2

好吧，我想我现在明白你的问题了。如果什么都没有发生，你可以使用未来尝试做一些事情，然后在一段时间后超时。例如：FutureTask<Void>&nbsp;task&nbsp;=&nbsp;new&nbsp;FutureTask<Void>(new&nbsp;Callable<Void>()&nbsp;{ &nbsp;&nbsp;@Override &nbsp;&nbsp;public&nbsp;Void&nbsp;call()&nbsp;throws&nbsp;Exception&nbsp;{ &nbsp;&nbsp;&nbsp;&nbsp;//&nbsp;Do&nbsp;DB&nbsp;stuff &nbsp;&nbsp;&nbsp;&nbsp;return&nbsp;null; &nbsp;&nbsp;}});Executor&nbsp;executor&nbsp;=&nbsp;Executors.newSingleThreadScheduledExecutor();executor.execute(task);try&nbsp;{ &nbsp;&nbsp;task.get(5,&nbsp;TimeUnit.SECONDS);}catch(Exception&nbsp;ex)&nbsp;{ &nbsp;&nbsp;//&nbsp;Handle&nbsp;your&nbsp;exception}