How to set a Timer in Java

Question

How to set a Timer  say for 2 minutes  to try to connect to a Database then throw exception if there is any issue in connection

User · Answer

new java util Timer   schedule new TimerTask             Override         public void run                 System out println  Executed                    your code here               1000 5 5000 mlsec  i e  5 seconds  u can change accordngly                  1000 5 1000 5

User · Answer

Android  if someone looking to implement timer on android using java      you need use UI thread like this to perform operations    Timer timer   new Timer    timer schedule new TimerTask                 Override             public void run                     ActivityName this runOnUiThread new Runnable                         Override                       public void run                               do something                                                                              2000

User · Answer

Ok  I think I understand your problem now   You can use a Future to try to do something and then timeout after a bit if nothing has happened   E g    FutureTask lt Void gt  task   new FutureTask lt Void gt  new Callable lt Void gt         Override   public Void call   throws Exception          Do DB stuff     return null           Executor executor   Executors newSingleThreadScheduledExecutor    executor execute task    try     task get 5  TimeUnit SECONDS     catch Exception ex         Handle your exception

User · Answer

So the first part of the answer is how to do what the subject asks as this was how I initially interpreted it and a few people seemed to find helpful   The question was since clarified and I ve extended the answer to address that   Setting a timer  First you need to create a Timer  I m using the java util version here    import java util Timer        Timer timer   new Timer      To run the task once you would do   timer schedule new TimerTask        Override   public void run            Your database code here        2 60 1000      Since Java-8 timer schedule    - gt     your database code here     2 60 1000     To have the task repeat after the duration you would do   timer scheduleAtFixedRate new TimerTask        Override   public void run            Your database code here        2 60 1000  2 60 1000       Since Java-8 timer scheduleAtFixedRate    - gt     your database code here     2 60 1000  2 60 1000     Making a task timeout  To specifically do what the clarified question asks  that is attempting to perform a task for a given period of time  you could do the following   ExecutorService service   Executors newSingleThreadExecutor     try       Runnable r   new Runnable              Override         public void run                    Database task                       Future lt   gt  f   service submit r        f get 2  TimeUnit MINUTES          attempt the task for two minutes   catch  final InterruptedException e           The thread was interrupted during sleep  wait or join   catch  final TimeoutException e           Took too long    catch  final ExecutionException e           An exception from within the Runnable task   finally       service shutdown        This will execute normally with exceptions if the task completes within 2 minutes   If it runs longer than that  the TimeoutException will be throw   One issue is that although you ll get a TimeoutException after the two minutes  the task will actually continue to run  although presumably a database or network connection will eventually time out and throw an exception in the thread   But be aware it could consume resources until that happens

User · Answer

Use this   long startTime   System currentTimeMillis    long elapsedTime   0L   while  elapsedTime  lt  2 60 1000          perform db poll check     elapsedTime    new Date    getTime   - startTime       Throw your exception

[java] How to set a Timer in Java?

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