Java tool/method to force-kill a child process

There is a leaner way to do this using Java JNA.

This works definitely for Windows and Linux, i assume that you can do the same for other platforms too.

The biggest problem of Java process handling is the lack of a method to get the process id of the process started with untime.getRuntime().exec().

Assuming you got the pid of a process, you always can start a kill -9 command in linux, or use similar ways to kill a process in windows.

Here is a way to get the process id natively for linux (borrowed from the selenium framework, 🙂 ), and with the help of JNA this also can be done for windows (using native Windows API calls).

For this to work (for Windows) you first have to get the JNA Library at JAVA NATIVE ACCESS (JNA): Downloads or get it from maven

Look at the following code, which will get the pid of a (in this example windows) program (most of the code is actually debris to get a working java program going):

import com.sun.jna.*;
import java.lang.reflect.Field;
import java.util.logging.Level;
import java.util.logging.Logger;

public class Main {

static interface Kernel32 extends Library {

    public static Kernel32 INSTANCE = (Kernel32) Native.loadLibrary("kernel32", Kernel32.class);

    public int GetProcessId(Long hProcess);
}

public static void main(String[] args) {
    try {
        Process p;

        if (Platform.isWindows())
            p = Runtime.getRuntime().exec("cmd /C ping msn.de");
        else if (Platform.isLinux())
            p = Runtime.getRuntime().exec("cmd /C ping msn.de");

        System.out.println("The PID: " + getPid(p));

        int x = p.waitFor();
        System.out.println("Exit with exitcode: " + x);

    } catch (Exception ex) {
        Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
    }
}

public static int getPid(Process p) {
    Field f;

    if (Platform.isWindows()) {
        try {
            f = p.getClass().getDeclaredField("handle");
            f.setAccessible(true);
            int pid = Kernel32.INSTANCE.GetProcessId((Long) f.get(p));
            return pid;
        } catch (Exception ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
    } else if (Platform.isLinux()) {
        try {
            f = p.getClass().getDeclaredField("pid");
            f.setAccessible(true);
            int pid = (Integer) f.get(p);
            return pid;
        } catch (Exception ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    else{}
    return 0;
}
}

Hope this helps, ;)…