How can I generate an MD5 hash?

java hash md5 hashcode
Akshay picture Akshay · Jan 6, 2009 · Viewed 1M times · Source

Is there any method to generate MD5 hash of a string in Java?

Answer

koregan picture koregan · Jan 6, 2009

The MessageDigest class can provide you with an instance of the MD5 digest.

When working with strings and the crypto classes be sure to always specify the encoding you want the byte representation in. If you just use string.getBytes() it will use the platform default. (Not all platforms use the same defaults)

import java.security.*;

..

byte[] bytesOfMessage = yourString.getBytes("UTF-8");

MessageDigest md = MessageDigest.getInstance("MD5");
byte[] thedigest = md.digest(bytesOfMessage);

If you have a lot of data take a look at the .update(byte[]) method which can be called repeatedly. Then call .digest() to obtain the resulting hash.

Related questions

Creating a hash from several Java string objects

What would be the fastest and more robust (in terms of uniqueness) way for implementing a method like public abstract String hash(String[] values); The values[] array has 100 to 1,000 members, each of a which with few dozen characters, and the …

Read More
Java - Hash algorithms - Fastest implementations

I want to know what is the best and fastest implementation of hash algorithms for Java especially MD5 and SHA-2 512 (SHA512) or 256. I want a function to get a string as an argument and return the hash as the result. …

Read More
Good Hash Function for Strings

I'm trying to think up a good hash function for strings. And I was thinking it might be a good idea to sum up the unicode values for the first five characters in the string (assuming it has five, otherwise …

Read More