How do you create a Message Digest with the Java Security API? (Message Digest code example)
Created May 4, 2012
Lennart Jorelid
A: A simple example of creating and using the MessageDigest class. Note that the factory method getInstance is the only way to create a MessageDigest object. After calling the digest method, the Message Digest object is reset to its original state.
Code example | public static void main(String[] args) throws Exception { // Create a Message Digest from a Factory method MessageDigest md = MessageDigest.getInstance("SHA-1"); // Create the message String orig = "And now for something completely different... the larch."; byte[] msg = orig.getBytes(); // Update the message digest with some more bytes // This can be performed multiple times before creating the hash md.update(msg); // Create the digest from the message byte[] aMessageDigest = md.digest(); // Printout System.out.println("Original: " + new String(msg)); System.out.println("Message Digest: " + new String(aMessageDigest)); } |
Resulting output | Original: And now for something completely different... the larch. Message Digest: ♦═7→ ╚B╩b╩l |