How do you turn on and off a monitor from within a Java application?

Question

How do you turn on and off a monitor from within a Java application?

In case you\'re wondering why, this is a kiosk style application where it would be great to turn

Answer 1

Assuming you deploy your Java Applications on Windows, you can use this WIN32API functions:

// turn off monitor
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, (LPARAM) 2); 

// turn on monitor
SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, (LPARAM) -1);    

Then you write a little C-JNI wrapper to functions that call the mentioned SendMessage and use the little wrapper to turn off the monitor from Java.

Answer 2

While you can query the monitor configurations with Java, there is no way to turn the monitors on and off programatically without using JNI.

Answer 3

I have seen this exe named nircmd on the net. It is a freeware and can be used on by anyone.It has a built in function for doing this.

nircmd.exe monitor off 

A detailed help is also found in the website. Just use it in your program and call it using

Runtime.getRuntime().exec(this.getClass().getResource("nircmd.exe").getPath());

or put it to the windows directory and run it from there.

Answer 4

You can open a full screen swing window, make it completely black, so the monitor, as far as observable behavior is concerned, is turned off.