Lock windows desktop from Java after timeout

Question

I want my java app to lock the windows desktop after a specific timeout. I have a timer which works fine, but I can't seem to execute the command to lock the workstation.

javax.swing.Timer tim = new javax.swing.Timer(1000, new ActionListener() {
   public void actionPerformed(ActionEvent e) {
   System.out.println("CARD NOT PRESENT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!");
   // LOCK SCREEN
   Runtime rt = Runtime.getRuntime();
   Process pr = rt.exec("%windir%/System32/rundll32.exe user32.dll,LockWorkStation");
   }
});

Is there some mistake in this? Or maybe an easier way to do this?

do you see the `CARD NOT PRESENT!...` text printed on standard out? — krock, Oct 04 '11 at 03:23

score 5 · Answer 1 · answered Mar 15 '12 at 15:28

5

Try absolute location:

Runtime.getRuntime().exec("C:\\Windows\\System32\\rundll32.exe user32.dll,LockWorkStation");

answered Mar 15 '12 at 15:28

Roman Malieiev

205
4
10

score 4 · Answer 2 · answered Oct 05 '15 at 12:49

4

This is working as well (tested on Windows 7 x86):

final String path = System.getenv("windir") + File.separator + "System32" + File.separator + "rundll32.exe";
Process pr = rt.exec(path + " user32.dll,LockWorkStation");

answered Oct 05 '15 at 12:49

Steve S.

923
2
9
19

score 4 · Accepted Answer · answered Oct 04 '11 at 03:27

I think there is a better way to test this :

1) put the command in a .bat file.

2) Run the bat file. does it work ?

3) If so , call the .bat file in your code.

4) Does it work ? If so, then you are done. I dont think there is any value in encoding windows specific code into runtime exec, just keep the bat file as a seperate file in your app .

Runtime.exec sometimes fails because the paths arent the same inside the JVM as they are in the native os.

Lock windows desktop from Java after timeout

3 Answers3