Submitted On 20-FEB-2002
Alindstrom
Well, the workaround is not sufficient since the "nice"
terminal window shows up again. It seems like the java app
does not have a handle to the JVM, so when closed the JVM
continues running using 10-11 MB memory in win2k.
I'll continue to look for a solution on this ..
Submitted On 07-SEP-2002
javarules.com
For the sake of the individual who wrote this and others who
may stumble upon it, this bug report should be closed. It is
much ado about nothing (based on a faulty program).
Shutdown hooks work fine when using javaw. For example,
execute the following program using javaw Test and you will
see that the file is written to the current working directory.
import java.io.*;
public class Test {
public static void main(String[] args) {
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
try{ PrintWriter pw = new PrintWriter(
new FileOutputStream("test.txt"));
pw.println("SHUTDOWN HOOKS RUNNING");
pw.close();
} catch(Exception e) {}
System.err.println("SHUTDOWN HOOKS RUNNING");
}
});
}
}
Of course, the System.out.println message will not appear,
but that is only because there is no console.
Submitted On 06-OCT-2003
bsampieri
While I agree that java.exe and javaw.exe should behave the
same in this regard, maybe the reason is that javaw.exe is
more suited for GUI apps, and those could therefore use a
window listener on the GUI frame/window to handle cleanup?
Submitted On 14-OCT-2003
mad_frog
To javarules.com
Modify your code this way:
import java.io.*;
public class Test {
public static void main(String[] args) {
Runtime.getRuntime().addShutdownHook(new Thread() {
public void run() {
try{ PrintWriter pw = new PrintWriter(
new FileOutputStream("test.txt"));
pw.println("SHUTDOWN HOOKS RUNNING");
pw.close();
} catch(Exception e) {}
System.err.println("SHUTDOWN HOOKS RUNNING");
}
});
//!
Thread.currentThread().sleep(600000);
}
}
Run this code using javaw.exe in Windows 2000 and Log Off
Windows while the thread is sleeping. The shutdown hook will
not be executed. I had to write my own native launcher that
uses java.exe and hides the console window using Windows
technique because of this issue.
Submitted On 15-OCT-2003
gary.craig
Using java.exe instead of javaw.exe is not a reasonable
workaround.
Javaw should be fixed to behave as documented.
This issue exists on XP (at least) in addition to W2000.
Submitted On 03-FEB-2004
gary.craig
This also exists in 1.4.2_02, on XP
Submitted On 23-FEB-2004
mthornton
If the application concerned has windows then using
java.exe doesn't work either. The shutdown hook at
logoff only works for applications that have no gui. Nor
is it possible to listen for events on the frame/window --
- no close event is received at logoff.
For applications with a gui, Windows send a message
to the applications message loop which java current
ignores, but this is the ONLY way the JVM will be
notified of impending process termination due to user
logoff or operating system shutdown.
So javarules.com and bsampieri, neither of you have
properly understood the problem described in this bug
report. Yes, shutdown does work if you exit all (non
daemon) threads or if you call System.exit. The
problem is it does not run in response to external
messages from the operating system.
Submitted On 23-FEB-2004
mthornton
To behave properly the JVM should process the
WM_ENDSESSION message. It should not return from
this message until all shutdown tasks have been
completed. The WM_QUIT message should also be
handled in this way.
Submitted On 24-FEB-2004
mthornton
On further investigation it seems that processes with
message loops may receive both a signal and the
WM_ENDSESSION message. However the process is
liable to abrupt termination as soon as the message
handler returns, and thus before the shutdown hooks
have completed (or even started). The JVM should be
changed so that both the signal and the
WM_ENDSESSION message can initiate shutdown
processing and that both block until that processing is
complete. It is also likely that the timing of signals,
WM_ENDSESSION messages and process
termination varies between versions of Windows
(Windows 9x is documented as having slightly different
behaviour).
This problem should be reclassified as a bug not an
RFE. An RFE would be the ability to choose the
response to a WM_QUERYENDSESSION message
(e.g. decline the request for logoff).
Submitted On 15-APR-2006
cowwoc
I tracked down the problem. Java's WindowProc handles WM_ENDSESSION just fine, but it does not actually wait for the shutdown hooks to finish executing before returning.
The trick is this: if you have a JFrame visible, shutdown hooks will run to termination (Java is waiting on the JFrame to shut down) whereas if you have no visible windows, the application will get terminated immediately without running the shutdown hooks.
Submitted On 15-APR-2006
cowwoc
I finally found a workaround for this issue!
On initialization, run:
JWindow shutdownHookWorkaround = new JWindow();
shutdownHookWorkaround.setSize(0, 0);
shutdownHookWorkaround.setVisible(true);
Runtime.getRuntime().addShutdownHook(shutdownHook);
then inside your shutdown hook, run:
EventQueue.invokeLater(new Runnable()
{
public void run()
{
shutdownHookWorkaround.setVisible(false);
shutdownHookWorkaround.dispose();
}
});
Submitted On 10-APR-2007
The workaround from cowwoc works for me in that way, that i receive the shutdown signal, but the jvm is still shut down immediately :-/ When using java (not javaw) the Windows message for terminating the application comes up and the jvm waits until the shutdown is comlete. So, i think the problem still exists...
Submitted On 03-JUL-2008
I am having the exact same issue here and it is really frustrating. My issue occurs because I have a SystemTray application using the JDIC module. When I run it with java.exe the shutdown hooks run to completion. When I run using Javaw.exe the shutdown hook isn't called at all. This is because there isn't a visible window in the system to catch the window shutdown message.
When I use the work around of creating the JWindow of size 1 the shutdown hook is invoked but rarely completes because the JVM shuts down too quickly. :(
PLEASE NOTE: JDK6 is formerly known as Project Mustang
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