Close another application from Java but not started by the present Java application

Question

Basically if I start a Notepad by going to start->accessories->notepad then my Java program should close this. Is it possible? If not in Java, any other language?

Answer 1

If you know PID of a process use below code to kill a application from Java:

Runtime.getRuntime().exec("taskkill /F /PID <process_id>");

where, is your process id, /F is used to force kill. Note this works only if you're using windows.

From here you can expand this to work for getting process id dynamically and killing instead of hard-coding.

Using system property os.name you can get name of os and change command accordingly.

Answer 2

In addition to the post above, you can filter out the PID with this code(don´t know if it can work more simple)

This code does list all Processes, and you can filter out some specific one, if you want

package runtime;

import java.util.Scanner;

public class Process_Check {

 public static void main(String[] args) throws Exception {
        Processes.ALL_PROCESSES.listProcesses();
   }
 public static enum Processes implements IProcessListingStrategy {
        ALL_PROCESSES;

        private IProcessListingStrategy processListing = selectProcessListingStrategy();

        public void listProcesses() throws Exception {
            processListing.listProcesses();
        }

        private IProcessListingStrategy selectProcessListingStrategy() {
            //todo add support for mac ...
            return isWindows() ? new WinProcessListingStrategy() : new LinuxProcessListingStrategy();
        }

        private static boolean isWindows() {
            return System.getProperty("os.name").toLowerCase().indexOf("win") >= 0;

        }
    }

    static interface IProcessListingStrategy {
        void listProcesses() throws Exception;
    }

    static abstract class AbstractNativeProcessListingStrategy implements IProcessListingStrategy {
        public void listProcesses() throws Exception {
            Process process = makeProcessListingProcessBuilder().start();
            Scanner scanner = new Scanner(process.getInputStream());
            while (scanner.hasNextLine()) {
                System.out.println(scanner.nextLine());
            }
            scanner.close();
            process.waitFor();
        }

        protected abstract ProcessBuilder makeProcessListingProcessBuilder();
    }
    static class WinProcessListingStrategy extends AbstractNativeProcessListingStrategy {
        @Override
        protected ProcessBuilder makeProcessListingProcessBuilder() {
            return new ProcessBuilder("cmd", "/c", "tasklist");
        }
    }

    static class LinuxProcessListingStrategy extends AbstractNativeProcessListingStrategy {
        @Override
        protected ProcessBuilder makeProcessListingProcessBuilder() {
            return new ProcessBuilder("ps", "-e");
        }
    }
}