I get exception when using Thread sleep x or wait

Question

I have tried to delay - or put to sleep - my Java program  but an error occurs   I m unable to use Thread sleep x  or wait    The same error message appears       unreported exception java lang InterruptedException  must be caught or declared to be thrown    Is there any step required before using the Thread sleep   or wait   methods

User · Answer

Have a look at this excellent brief post on how to do this properly    Essentially  catch the InterruptedException  Remember that you must add this catch-block  The post explains this a bit further

User · Answer

Thread sleep   is simple for the beginners and may be appropriate for unit tests and proofs of concept      But please DO NOT use sleep   for production code  Eventually sleep   may bite you badly    Best practice for multithreaded multicore java applications to use the  thread wait  concept  Wait releases all the locks and monitors held by the thread  which allows other threads to acquire those monitors and proceed while your thread is sleeping peacefully    Code below demonstrates that technique   import java util concurrent TimeUnit  public class DelaySample       public static void main String   args           DelayUtil d   new DelayUtil           System out println  started    new Date            d delay 500          System out println  half second after    new Date            d delay 1  TimeUnit MINUTES           System out println  1 minute after    new Date               DelayUtil implementation   import java util concurrent TimeUnit  import java util concurrent locks Condition  import java util concurrent locks ReentrantLock   public class DelayUtil                   Delays the current thread execution          The thread loses ownership of any monitors          Quits immediately if the thread is interrupted                param durationInMillis the time duration in milliseconds           public void delay final long durationInMillis          delay durationInMillis  TimeUnit MILLISECONDS                        param duration the time duration in the given   code sourceUnit         param unit            public void delay final long duration  final TimeUnit unit            long currentTime   System currentTimeMillis            long deadline   currentTime unit toMillis duration           ReentrantLock lock   new ReentrantLock            Condition waitCondition   lock newCondition             while   deadline-currentTime  gt 0                try                   lock lockInterruptibly                        waitCondition await deadline-currentTime  TimeUnit MILLISECONDS                 catch  InterruptedException e                    Thread currentThread   interrupt                    return                finally                   lock unlock                              currentTime   System currentTimeMillis

User · Answer

As other users have said you should surround your call with a try      catch      block  But since Java 1 5 was released  there is TimeUnit class which do the same as Thread sleep millis  but is more convenient  You can pick time unit for sleep operation   try       TimeUnit NANOSECONDS sleep 100       TimeUnit MICROSECONDS sleep 100       TimeUnit MILLISECONDS sleep 100       TimeUnit SECONDS sleep 100       TimeUnit MINUTES sleep 100       TimeUnit HOURS sleep 100       TimeUnit DAYS sleep 100     catch  InterruptedException e          Handle exception     Also it has additional methods   TimeUnit Oracle Documentation

User · Answer

Alternatively  if you don t want to deal with threads  try this method   public static void pause int seconds       Date start   new Date        Date end   new Date        while end getTime   - start getTime    lt  seconds   1000           end   new Date              It starts when you call it  and ends when the number of seconds have passed

User · Answer

public static void main String   args  throws InterruptedException       type code     short z 1000    Thread sleep z    will provide 1 second delay  alter data type of z or value of z for longer delays required         type code     eg -  class TypeCasting      public static void main String   args  throws InterruptedException       short f   1      int a   123687889      short b   2      long c   4567      long d 45      short z 1000      System out println  Value of a b and c are n    a     n    b     n    c    respectively        c   a      b    short  c      System out println  Typecasting                   Thread sleep z       System out println  Value of B after Typecasting    b       System out println  Value of A is    a

User · Answer

When using Android  the only time when I use Java  I would recommend using a handler instead putting the thread to sleep   final Handler handler   new Handler        handler postDelayed new Runnable              Override         public void run                 Log i TAG   I ve waited for two hole seconds to show this                       2000     Reference  http   developer android com reference android os Handler html

User · Answer

Put your Thread sleep in a try catch block   try         thread to sleep for the specified number of milliseconds     Thread sleep 100     catch   java lang InterruptedException ie        System out println ie

User · Answer

Use java util concurrent TimeUnit   TimeUnit SECONDS sleep 1     Sleep for one second or  TimeUnit MINUTES sleep 1     Sleep for a minute   As this is a loop  this presents an inherent problem - drift  Every time you run code and then sleep you will be drifting a little bit from running  say  every second  If this is an issue then don t use sleep   Further  sleep isn t very flexible when it comes to control   For running a task every second or at a one second delay I would strongly recommend a  ScheduledExecutorService  1  and either  scheduleAtFixedRate  2  or  scheduleWithFixedDelay  3    To run the method myTask every second  Java 8    public static void main String   args        final ScheduledExecutorService executorService   Executors newSingleThreadScheduledExecutor        executorService scheduleAtFixedRate App  myTask  0  1  TimeUnit SECONDS      private static void myTask         System out println  Running

User · Answer

My ways to add delay to a Java program   public void pause1 long sleeptime        try           Thread sleep sleeptime         catch  InterruptedException ex              ToCatchOrNot          public void pause2 long sleeptime        Object obj   new Object        if  sleeptime  gt  0            synchronized  obj                try                   obj wait sleeptime                 catch  InterruptedException ex                      ToCatchOrNot                                 public void pause3 long sleeptime        expectedtime   System currentTimeMillis     sleeptime      while  System currentTimeMillis    lt  expectedtime              Empty Loop              This is for sequential delay but for Loop delays refer to Java Delay Wait

User · Answer

You have a lot of reading ahead of you  From compiler errors through exception handling  threading and thread interruptions  But this will do what you want   try       Thread sleep 1000                     1000 milliseconds is one second    catch InterruptedException ex        Thread currentThread   interrupt

User · Answer

A simpler way to wait is to use System currentTimeMillis    which returns the number of milliseconds since midnight on January 1  1970 UTC  For example  to wait 5 seconds   public static void main String   args          some code     long original   System currentTimeMillis        while  true            if  System currentTimeMillis - original  gt   5000                break                        more code after waiting     This way  you don t have to muck about with threads and exceptions  Hope this helps

User · Answer

Try this   try       Thread sleep 100    catch Exception e       System out println  Exception caught

User · Answer

Use the following coding construct to handle exceptions  try     Thread sleep 1000     catch  InterruptedException ie          Handle exception

[java] I get exception when using Thread.sleep(x) or wait()

Examples related to java

Examples related to sleep