Reading an image in byte form

Question

hii guys
i m trying to read an image and convert it to byte array and later to do some change in that byte array and later recreate a new image.
For that i m using FileInputStream and FileOutputStream and its read and write methods
but now i dont know how to append that byte and recreate that image.
actually i want to do that , convert the image in byte array form and replacing some bytes of the image by my text msg bytes and recreate a new image.
how an i do that.
plz help me.
its urgent.

Answer 1

import java.io.*;
class image
public static void main(String[] arg) throws IOException
String msg;
int len,i;
FileInputStream fin;
FileOutputStream fout;
try
try
fin=new FileInputStream("01.jpg");
catch( Exception e)
System.out.println("Input image not found");
return;
try
fout=new FileOutputStream("001.jpg");
catch( Exception e)
System.out.println("output image cannt be created");
return;
catch(Exception e)
System.out.println("output image cannt be created");
return;
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
System.out.println("Enter the secret msg :: ");
msg=br.readLine();
byte[] msg1=msg.getBytes();
len=msg1.length;
System.out.println(len);
for(i=0;i<len;i++)
System.out.println(msg1);
try
do
byte by=(byte)fin.read();
//System.out.print(" "+by);
if(fin.available()>0)
fout.write(by);
}while(fin.available()>0);
catch(Exception e)
System.out.println("File error");
fin.close();
fout.close();
till now i only imputed the sg , change it into byte form .
now i want to replace the msg bytes into the image byte as :- 1 image byte ,1 msg byte, 1 image byte , 1 msg byte........ so on
until the msg bytes are not finished.