Example (from Wikipedia):
import com.sun.jna.win32.StdCallLibrary;
import com.sun.jna.Native;
/** Simple example of Windows native library declaration and usage. */
public class BeepExample {
public interface Kernel32 extends StdCallLibrary {
// FREQUENCY is expressed in hertz and ranges from 37 to 32767
// DURATION is expressed in milliseconds
public boolean Beep(int FREQUENCY, int DURATION);
public void Sleep(int DURATION);
}
public static void main(String[] args) {
Kernel32 lib = (Kernel32) Native.loadLibrary("kernel32",
Kernel32.class);
lib.Beep(698, 500);
lib.Sleep(500);
lib.Beep(698, 500);
}
}
In this case, we load it from the "kernel32.dll" library.
I hope this makes JNA clearer.
EDIT: I'll explain the code:
You need to define an interface(that extends com.sun.jna.Library) with the functions you need from the library.
Then, call com.sun.jna.Native.loadLibrary("LibraryName", InterfaceName.class).
Finally, store the output in a variable with the type of the interface.
Just call the functions from that variable.
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