I call Process32First function to get info of first process of running processes. But it does not return anything. It does not change my pe variable's value.

Here is complete code of my class :

import com.sun.jna.FromNativeContext; import com.sun.jna.Native; import com.sun.jna.NativeLong; import com.sun.jna.Platform; import com.sun.jna.Pointer; import com.sun.jna.PointerType; import com.sun.jna.Structure;

//import com.sun.jna.Structure.ByReference; import com.sun.jna.ptr.ByReference; import com.sun.jna.ptr.PointerByReference; import com.sun.jna.win32.StdCallLibrary; import com.sun.jna.win32.W32APIFunctionMapper; import com.sun.jna.win32.W32APITypeMapper;

import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date;

import java.util.HashMap; import java.util.Map;

public class Win32IdleTime {

static byte[] buff= new byte[1024]; static char[] tmp= new char[1024]; static String buf =" ";

public interface Kernel32 extends StdCallLibrary { Kernel32 INSTANCE = (Kernel32)Native.loadLibrary("kernel32", Kernel32.class);

class HANDLE extends PointerType { /** Override to the appropriate object for INVALID_HANDLE_VALUE. */ public Object fromNative(Object nativeValue, FromNativeContext context) { Object o = super.fromNative(nativeValue, context); if (INVALID_HANDLE_VALUE.equals(o)) return INVALID_HANDLE_VALUE; return o; } } /** Constant value representing an invalid HANDLE. */ HANDLE INVALID_HANDLE_VALUE = new HANDLE() { { super.setPointer(Pointer.createConstant(-1)); } public void setPointer(Pointer p) { throw new UnsupportedOperationException("Immutable reference"); } };

HANDLE CreateToolhelp32Snapshot(int dwFlags,int th32ProcessID); boolean CloseHandle(HANDLE hObject);

public class PROCESSENTRY32 extends Structure {

public static class ByReference extends PROCESSENTRY32 implements Structure.ByReference {};

public int dwSize; public int cntUsage; public int th32ProcessID; public Pointer th32DefaultHeapID; //ULONG_PTR public int th32ModuleID; public int cntThreads; public int th32ParentProcessID; public NativeLong pcPriClassBase; public int dwFlags; public char[] szExeFile;

public PROCESSENTRY32() { szExeFile = new char[250]; } }

boolean Process32First(HANDLE hSnapshot, PROCESSENTRY32.ByReference lppe); boolean Process32Next(HANDLE hSnapshot, PROCESSENTRY32.ByReference lppe); //PeByReference lppe

HANDLE OpenProcess(int dwDesiredAccess, boolean bInheritHandle, int dwProcessId); int GetPriorityClass(HANDLE hProcess);

};

public static boolean get_Process_List() { Kernel32.HANDLE hProcessSnap; Kernel32.HANDLE hProcess; Kernel32.PROCESSENTRY32 pe32; Kernel32.PROCESSENTRY32.ByReference pe;

int dwPriorityClass;

if (Platform.isWindows()) {

Kernel32 kernel32 = Kernel32.INSTANCE;

pe = new Kernel32.PROCESSENTRY32.ByReference();

hProcessSnap = kernel32.CreateToolhelp32Snapshot( 0x00000002, 0 ); if( hProcessSnap == kernel32.INVALID_HANDLE_VALUE ) { System.out.println("CreateToolhelp32Snapshot (of processes)"); return false; } // Set the size of the structure before using it. // Retrieve information about the first process, // and exit if unsuccessful if( !kernel32.Process32First( hProcessSnap, pe ) ) {

kernel32.CloseHandle( hProcessSnap ); // clean the snapshot object return false;

}

// Now walk the snapshot of processes, and // display information about each process in turn do {

System.out.println("\n \n==================================================== =" ); System.out.println("\nPROCESS NAME: " + pe.szExeFile );

System .out.println("\n-----------------------------------------------------" );

// Retrieve the priority class. dwPriorityClass = 0; hProcess = kernel32.OpenProcess( 0x0400, false, pe.th32ProcessID ); if( hProcess == null ) System.out.println("OpenProcess"); else { dwPriorityClass = kernel32.GetPriorityClass( hProcess ); if( dwPriorityClass==0 ) System.out.println("GetPriorityClass"); kernel32.CloseHandle( hProcess ); }

System.out.println( "\n Process ID = "+ pe.th32ProcessID ); System.out.println( "\n Thread count = "+ pe.cntThreads ); System.out.println( "\n Parent process ID = "+ pe.th32ParentProcessID ); System.out.println( "\n Priority base = "+ pe.pcPriClassBase ); if( dwPriorityClass!=0 ) System.out.println( "\n Priority class = "+ dwPriorityClass );

} while( kernel32.Process32Next( hProcessSnap, pe ) );

kernel32.CloseHandle( hProcessSnap ); return true;

} return false; }

Sincerely, Olzii