JNA - Query Windows Processes

Question

I'm trying to use JNA to return details on a specific Windows Process. Not exactly sure how to do this. Couldn't find much on the interwebs for help. Some information I would like returned include CPU and memory usage. The below is just an example I found.

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;

import com.sun.jna.*;
import com.sun.jna.Library.Handler;
import com.sun.jna.platform.win32.*;
import com.sun.jna.platform.win32.Advapi32Util.*;
import com.sun.jna.platform.win32.WinNT.*;
import com.sun.jna.ptr.IntByReference;
import com.sun.jna.win32.*;

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


public class WindowsProcess {

    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));  
        Thelp32.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 1

This works with JNA 3.5.0. The example you have isn't compatible with more recent versions of the library, I think.

import com.sun.jna.platform.win32.Kernel32;
import com.sun.jna.platform.win32.Tlhelp32;
import com.sun.jna.platform.win32.WinDef;
import com.sun.jna.platform.win32.WinNT;
import com.sun.jna.win32.W32APIOptions;
import com.sun.jna.Native; 

public class ListProcesses {
    public static void main(String[] args) {
        Kernel32 kernel32 = (Kernel32) Native.loadLibrary(Kernel32.class, W32APIOptions.UNICODE_OPTIONS);
        Tlhelp32.PROCESSENTRY32.ByReference processEntry = new Tlhelp32.PROCESSENTRY32.ByReference();          

        WinNT.HANDLE snapshot = kernel32.CreateToolhelp32Snapshot(Tlhelp32.TH32CS_SNAPPROCESS, new WinDef.DWORD(0));
        try  {
            while (kernel32.Process32Next(snapshot, processEntry)) {             
                System.out.println(processEntry.th32ProcessID + "\t" + Native.toString(processEntry.szExeFile));
            }
        }
        finally {
            kernel32.CloseHandle(snapshot);
        }
    } 
}

See also my answer elsewhere .