BufferedReader fileIn= new  BufferedReader( new  InputStreamReader( new  FileInputStream( chooser.getSelectedFile().getPath()  ),"UTF-8"));

String strLine;
 while  ((strLine = fileIn.readLine()) !=  null ) {
      strBuffer.append(strLine);
      strBuffer.append( "\r\n" );
}
fileIn.close();

txtFormat.setText(strBuffer.toString());

ByteArrayOutputStream baos =  new  ByteArrayOutputStream();
baos.write(txtFormat.getText().getBytes(),  0 , txtFormat.getText().length());
 byte  []btTmp = baos.toByteArray();

FileInputStream fileInStream =  new  FileInputStream(chooser.getSelectedFile().getPath());
                
 byte  []btTmp2 =  new   byte [fileInStream.available()];
fileInStream.read(btTmp2);
System.out.println(btTmp2[ 0 ] );
System.out.println(btTmp2[ 1 ] );
System.out.println(btTmp2[ 2 ] );