File Input Stream

Question

Hello !
The FileInputStream has a constructor which uses FileDescriptor object as "FileInputStream(FileDescriptor fdobj)"
The practical use of FileDescriptor object is the FileInputStream and FileOutputStream to contain it.
Can someone help me how to make an elaborate use of it ? I want to use it in some manner in the following program .
God bless you.
NADEEM.
import java.io.* ;
public class CopyingText {
public static void main(String args[])  { 
Thread t = new Thread();
  try {
   System.out.println("Enter java CopyingText Source.txt Target.txt");
   FileInputStream  a = new FileInputStream(args[0]);
   FileOutputStream b = new FileOutputStream(args[1],true);        
   System.out.println("Source size: " + a.available());
   System.out.println(a.getFD());
    CopyingTxt rw  = new CopyingTxt(a,b);
    rw.fileCopying();
//    rw.bytesAvailable();             Giving IOException: Bad file descriptor : Reason ?
  } catch(Exception e) {
    System.out.println("Exception : main() :" + e );
    t.dumpStack();
class CopyingTxt   {
  private int i  , j  ;
  FileInputStream  fa ;
  FileOutputStream fb ;
  CopyingTxt(FileInputStream a, FileOutputStream b) {
   fa = a ;
   fb = b ;
  public int bytesAvailable() throws IOException {
   System.out.println(fa.getFD());
   System.out.println(fa.available());
    return fa.available() ;
  public void fileCopying() throws IOException {
   do {
    i = fa.read();
    j++ ;                                  
    if(i != -1) fb.write(i) ;
   } while(i != -1);                       //EOF condition  -1 .
   System.out.println("Bytes read : " + (j-1) + " / " + fa.available());
   bytesAvailable();
   fa.close();
//    fa.finalize();
   fb.close();
//    fb.finalize();
}

Answer 1

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