CODEWITHSUNDEEP
javaencryption
umb
umb

Reputation: 3

Problems with encrypt and decrypt

I'm trying to write code in Java that will encrypt file. I had used example from this site: http://www.avajava.com/tutorials/lessons/how-do-i-encrypt-and-decrypt-files-using-des.html

Everything works fine but I need code that will overwrite original file with encrypted one. I'd changed only this:

FileInputStream fis = new FileInputStream("original.txt");
FileOutputStream fos = new FileOutputStream("original.txt");
encrypt(key, fis, fos);

FileInputStream fis2 = new FileInputStream("original.txt");
FileOutputStream fos2 = new FileOutputStream("original.txt");

Encryption works, but after decryption decrypted file is empty. Can someone explain me what's the problem and how to solve it?

Thanks !

Upvotes: 0

Views: 144

Answers (1)

erickson
erickson

Reputation: 269857

You shouldn't read and overwrite the same file simultaneously with FileInputStream and FileOutputStream. Often, you'll get lucky, but the behavior is going to vary based on the underlying system, and that's not good. Instead, write to a temporary file, then move the temporary file to the location of the original file.

Upvotes: 2

Related Questions