public static String getStackTrace( Throwable aThrowable ) { 
    Writer result = new StringWriter(); 
    PrintWriter printWriter = new PrintWriter( result ); 
    aThrowable.printStackTrace( printWriter ); 
    return result.toString(); 
  }

JTextArea myConsole = new JTextArea(); 
JTextAreaOutputStream outStream = new JTextAreaOutputStream(myConsole); 
JTextAreaOutputStream errStream = new JTextAreaOutputStream(myConsole); 
System.setOut(new PrintStream(outStream)); 
System.setErr(new PrintStream(errStream));

import java.io.*;

public class LineCount
{
     static public void main(String args[]) throws Exception
     {

          //Change the directory where the count files are existing
          File di   = new File("c:/count");
          File fl[] = di.listFiles();
          int j;
          int count=0;
          String str="";
          String totalinfo="";

           for (j=0; j < fl.length; j++)
          {
              System.out.println(""+fl[j]);
              FileInputStream fis = new FileInputStream(fl[j].getCanonicalFile());
              LineNumberReader l = new LineNumberReader(
                                                  new BufferedReader(new InputStreamReader(fis)));
              while ((str=l.readLine())!=null)
             {
                count = l.getLineNumber();
             }
            System.out.println(count);

            String filename = fl[j].getName().toString();
            totalinfo = filename+"-------------"+count;

             FileOutputStream file = new FileOutputStream("c:/one.txt",true); //append
            PrintStream printtofile = new PrintStream(file);
            printtofile.println(totalinfo);
            printtofile.close();
            file.close();
        }
   }
}

public static void main(String args[]) 

{ 

try 

{ 

File dir = new File("c:\\"); 

String[] children = dir.list(); 

if (children == null) 

{ 

System.out.println("Directory does not exist or is not a Directory"); 

} else 

{ 

for (int i=0; i < children.length ; i++ ) 

// Get filename of file or directory 

{ 

String filename = new String ( children[i]); 

System.out.println(filename); 

} 

} 

// It is also possible to filter the list of returned files. 

// This example does not return any files that start with `.'. 

FilenameFilter filter = new FilenameFilter() { 

public boolean accept(File dir, String name) { 

return !name.startsWith("."); 

} 

}; 

children = dir.list(filter); 

// The list of files can also be retrieved as File objects 

File[] files = dir.listFiles(); 

// This filter only returns directories 

FileFilter fileFilter = new FileFilter() { 

public boolean accept(File file) { 

return file.isDirectory(); 

} 

}; 

files = dir.listFiles(fileFilter); 

} 

catch (Exception ioe){ 

ioe.printStackTrace(); 

} 

}