Why is file size increasing while copiying contents of the file.

Question

Hi,
Iam copying the contents of a file to another file using streams.But while doing this the size of the destination file is greater than the source file.For example, if iam copying the contents of file A whose size is 78 KB into file B then the size of B is 80 KB. Any body please explain the reason for this.The code i used for copying is given below.
Thanks in advance.
public static boolean copyFile(File srcFile,File destFile){
          FileInputStream fis = null;
          FileOutputStream fos = null;
          boolean isCopySucess = false;
          //============================================
          int ReadBytes = 0;
          int BUFSIZ = 4096;
          long fileSize ;
          long copiedBytes=0;
          try
                    fis = new FileInputStream(srcFile);
                    fos = new FileOutputStream(destFile);
                    fileSize = srcFile.length();
                    byte Buf[] = new byte[BUFSIZ];
                    while(copiedBytes < fileSize)
                         ReadBytes = fis.read(Buf, 0, BUFSIZ);
                         fos.write(Buf);
                         copiedBytes +=ReadBytes;
                    isCopySucess = true;
          }catch(Exception ex)
               isCopySucess = false;
               ex.printStackTrace();
          //============================================
          finally{
               try {
                    if(fis != null)
                         fis.close();
                    if(fos != null)
                         fos.close();
               } catch (final IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
               return isCopySucess;
     }

Answer 1

ReadBytes = fis.read(Buf, 0, BUFSIZ);
fos.write(Buf, 0, ReadBytes);