Re: Using "synchronized" but still getting IllegalMonitorStateException

From:
Robert Klemme <shortcutter@googlemail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 06 Apr 2009 19:26:35 +0200
Message-ID:
<73usbpF111sgeU1@mid.individual.net>
On 06.04.2009 18:54, laredotornado wrote:

I'm trying to execute this bit of JUnit test code (Java 1.5):

    public void testEventLoggerFailure() {
        try {
            synchronized(this) {
                EventLogger el = new EventLogger(null,
                       null,
                       null,
                       null);
                el.start();
                el.wait();
            } // synchronized
        } catch (Exception e) {
            e.printStackTrace();
            fail(e.getMessage());
        } // catch
    } // testEventLoggerFailure

but yet, at the "el.wait()" line the below exceptioin is thrown ...

java.lang.IllegalMonitorStateException: current thread not owner
    at java.lang.Object.wait(Native Method)
 > ...

Any ideas? Thanks, - Dave


You can only wait on the monitor that you are holding, i.e. "this" in
the case above. Frankly, I have no idea what you are trying to achieve
with the code and it seems you do not know how synchronized, wait and
notify work. I suggest you get yourself a copy of Doug Lea's book:

http://www.informit.com/store/product.aspx?isbn=0201310090&rll=1

Cheers

    robert

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