Getting problem while editing a binary file

Question

Hi All,
I am trying to edit a binary file using Java.The file contain a string that I have to replace with some other string.For exanple let us assume following is the content of the file -
õgëÓÌ©™ÿÿ ABC õgëÓÌ©™ÿÿ
Here, I have to replace this ABC(a string) with some other string.Now,if the replace string length is more than 3(the length of exiting string) then, the binary file is generating some blank space at the end.
My Code::
//Here I am trying to insert "Hello" in place of "ABC".
FileInputStream fis = null;
fis = new FileInputStream(aFile);
FileOutputStream to = new FileOutputStream(aF);
byte[] aTes=new byte[1024];
String str="Hello";
aTes=str.getBytes();
byte[] buffer = new byte[4096];
int bytesRead;
while ((bytesRead = fis.read(buffer)) != -1) {
to.write(buffer, 0, 5);
to.write(aTes);
to.write(buffer, 5, bytesRead);
Plesae guide me to solve this problem.
Regards,
Soumitra

Answer 1

Okay. So was that code you posted supposed to be a failed answer to the question, and you need help with fixing it? Because to me it just looks like code which copies a file, with random modifications. It doesn't look for ABC in any way, it uses the magic number "5" for no apparent reason, and the other modifications are buggy too. So clarification of what the code is supposed to be would be helpful.