qui peut me corriger ce programme?

je veux que  programme affiche la liste des processus avec leurs répertoires, mais ca marche pas ,qui peut m'aider?


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.*;
import java.lang.*;
 
 
public class  ListProc{
 
    public static void main(String[] args) {
        String strOutput = "";
        String strError = "";
       
 File rep=null;
 File dir=null;
        try {
         String [] command=new String[] {"tasklist"};
         String [] envp=new String[] {};
          Process p = Runtime.getRuntime().exec(command,envp, dir );
                     
            rep=dir;
            
            BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
            BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
            
 
            
           while (strOutput != null) {
 
               if (strOutput.length() < 1) {
                  } else   {
                            
                                System.out.println(strOutput);
                          
                }
                 
 
                strOutput = stdInput.readLine();
            }
            
       
 }
 
            strError = stdError.readLine();
 
            if (strError != null) {
                System.out.println("An error occured");
 
                while (strError != null) {
                    System.out.println(strError);
                    strError = stdError.readLine();
                }
            }
        } catch (IOException ioe) {
            System.out.println("An IOException occured");
            ioe.printStackTrace();
            System.exit(-1);
        }
        catch (SecurityException s){
         System.out.println(s);}
       
   
    }
    }