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 |
Comment and Contribute
