Sleep method of java.lang.Thread is used to pause current execution of thread for specific period of time.
Some important points about sleep method are :
- It causes current executing thread to sleep for specific amount of time.
- Its accuracy depends on system timers and schedulers.
- It keeps the monitors it has acquired, so if it is called from synchronized context, no other thread can enter that block or method.
- If we call interrupt() method , it will wake up the sleeping thread.
|
1 2 3 4 5 6 |
synchronized(lockedObject) { Thread.sleep(1000); // It does not release the lock on lockedObject. // So either after 1000 miliseconds, current thread will wake up, or after we call //t. interrupt() method. |
Example: Create a class FirstThread.java as below.
|
1 2 3 4 5 6 7 8 9 10 11 12 |
package org.arpit.java2blog.thread; public class FirstThread implements Runnable{ public void run() { System.out.println("Thread is running"); } } |
Create main class named ThreadSleepExampleMain.java
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 |
package org.arpit.java2blog.thread; public class ThreadSleepExampleMain { public static void main(String args[]) { FirstThread ft= new FirstThread(); Thread t=new Thread(ft); t.start(); long startTime=System.currentTimeMillis(); try { // putting thread on sleep Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } long endTime=System.currentTimeMillis(); long timeDifference=(endTime-startTime); System.out.println("Time difference between before and after sleep call: "+timeDifference); } } |
When you run above program, you will get following output.
|
1 2 3 4 |
Thread is running Time difference between before and after sleep call: 1001 |
You can see there is delay of 1 milliseconds. As mentioned earlier,its accuracy depends on system timers and schedulers.
