How to get a list of current open windows/process

Question

Does any one know how do I get the current open windows or process of a local machine using Java?

What I'm trying to do is: list the current open task, windows or process open, like in Windows Taskmanager, but using a multi-platform approach - using only Java if it's possible.

Answer 1

On Windows there is an alternative using JNA:

import com.sun.jna.Native;
import com.sun.jna.platform.win32.*;
import com.sun.jna.win32.W32APIOptions;

public class ProcessList {

    public static void main(String[] args) {
        WinNT winNT = (WinNT) Native.loadLibrary(WinNT.class, W32APIOptions.UNICODE_OPTIONS);

        WinNT.HANDLE snapshot = winNT.CreateToolhelp32Snapshot(Tlhelp32.TH32CS_SNAPPROCESS, new WinDef.DWORD(0));

        Tlhelp32.PROCESSENTRY32.ByReference processEntry = new Tlhelp32.PROCESSENTRY32.ByReference();

        while (winNT.Process32Next(snapshot, processEntry)) {
            System.out.println(processEntry.th32ProcessID + "\t" + Native.toString(processEntry.szExeFile));
        }

        winNT.CloseHandle(snapshot);
    }
}

Answer 2

package com.vipul;

import java.applet.Applet;
import java.awt.Checkbox;
import java.awt.Choice;
import java.awt.Font;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class BatchExecuteService extends Applet {
    public Choice choice;

    public void init() 
    {
        setFont(new Font("Helvetica", Font.BOLD, 36));
        choice = new Choice();
    }

    public static void main(String[] args) {
        BatchExecuteService batchExecuteService = new BatchExecuteService();
        batchExecuteService.run();
    }

    List<String> processList = new ArrayList<String>();

    public void run() {
        try {
            Runtime runtime = Runtime.getRuntime();
            Process process = runtime.exec("D:\\server.bat");
            process.getOutputStream().close();
            InputStream inputStream = process.getInputStream();
            InputStreamReader inputstreamreader = new InputStreamReader(
                    inputStream);
            BufferedReader bufferedrReader = new BufferedReader(
                    inputstreamreader);
            BufferedReader bufferedrReader1 = new BufferedReader(
                    inputstreamreader);

            String strLine = "";
            String x[]=new String[100];
            int i=0;
            int t=0;
            while ((strLine = bufferedrReader.readLine()) != null) 
            {
        //      System.out.println(strLine);
                String[] a=strLine.split(",");
                x[i++]=a[0];
            }
    //      System.out.println("Length : "+i);

            for(int j=2;j<i;j++)
            {
                System.out.println(x[j]);
            }
        }
        catch (IOException ioException) 
        {
            ioException.printStackTrace();
        }

    }
}

   You can create batch file like 

TASKLIST /v /FI "STATUS eq running" /FO "CSV" /FI "Username eq LHPL002\soft" /FI "MEMUSAGE gt 10000" /FI "Windowtitle ne N/A" /NH

Answer 3

This is another approach to parse the the process list from the command "ps -e":

try {
    String line;
    Process p = Runtime.getRuntime().exec("ps -e");
    BufferedReader input =
            new BufferedReader(new InputStreamReader(p.getInputStream()));
    while ((line = input.readLine()) != null) {
        System.out.println(line); //<-- Parse data here.
    }
    input.close();
} catch (Exception err) {
    err.printStackTrace();
}

If you are using Windows, then you should change the line: "Process p = Runtime.getRun..." etc... (3rd line), for one that looks like this:

Process p = Runtime.getRuntime().exec
    (System.getenv("windir") +"\\system32\\"+"tasklist.exe");

Hope the info helps!

Answer 4

You can easily retrieve the list of running processes using jProcesses

List<ProcessInfo> processesList = JProcesses.getProcessList();

for (final ProcessInfo processInfo : processesList) {
    System.out.println("Process PID: " + processInfo.getPid());
    System.out.println("Process Name: " + processInfo.getName());
    System.out.println("Process Used Time: " + processInfo.getTime());
    System.out.println("Full command: " + processInfo.getCommand());
    System.out.println("------------------");
}

Answer 5

There is no platform-neutral way of doing this. In the 1.6 release of Java, a "Desktop" class was added the allows portable ways of browsing, editing, mailing, opening, and printing URI's. It is possible this class may someday be extended to support processes, but I doubt it.

If you are only curious in Java processes, you can use the java.lang.management api for getting thread/memory information on the JVM.

Answer 6

For windows I use following:

        Process process = new ProcessBuilder("tasklist.exe", "/fo", "csv", "/nh").start();
    new Thread(() -> {
        Scanner sc = new Scanner(process.getInputStream());
        if (sc.hasNextLine()) sc.nextLine();
        while (sc.hasNextLine()) {
            String line = sc.nextLine();
            String[] parts = line.split(",");
            String unq = parts[0].substring(1).replaceFirst(".$", "");
            String pid = parts[1].substring(1).replaceFirst(".$", "");
            System.out.println(unq + " " + pid);
        }
    }).start();
    process.waitFor();
    System.out.println("Done");