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Wait() Example

Phillipe Rodrigues
Ranch Hand

Joined: Oct 30, 2007
Posts: 165
I tried an example for wait() after reading a tutorial.

The Example is as below:

On executing theabove I get the below error.

Exception in thread "main" java.lang.IllegalMonitorStateException: current thread not owner
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(
at com.aciworldwide.application.TestApp.main(

Where am I doing wrong.What does the error mean how can I correct it?

amitabh mehra
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Joined: Dec 05, 2006
Posts: 98
wait() must be called from within a synchronized context and a thread cannot invoke wait() on an object until it owns that object's lock.
sarvesh meens
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Joined: Mar 31, 2006
Posts: 43

* Thread should obtain the object's monitor before invoking wait() or notify() on it.
* Locks,synchronized blocks/methods are the techniques to acquire object monitor. Depending on application requirement,suitable technique should be adopted.
* wait() should always be matched with a notify(). If you get rid of java.lang.IllegalMonitorStateException in the above example by aquiring the object's(one) monitor,main-thread will wait for-ever.
* You may find this discussion helpful.
[ June 05, 2008: Message edited by: sarvesh meens ]
Dawn Charangat
Ranch Hand

Joined: Apr 26, 2007
Posts: 249
should work correctly, if you put that wait call inside a synchronized block
Nitesh Kant

Joined: Feb 25, 2007
Posts: 1638

Hi Dawn,

It is generally not a good idea to WakeTheZombies
In all possibilities the original poster is not really waiting for inputs anymore!

apigee, a better way to API!
I agree. Here's the link:
subject: Wait() Example
It's not a secret anymore!