MD5 Encryption Java style

Here is a little nugget you might enjoy how to do some MD5 Encryption with Java pretty easy really.  Mostly taken from this book:

 

package test.md5.encrypt;

import java.io.ByteArrayInputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;

import junit.framework.TestCase;

public class TestMessageDigest extends TestCase {
	private static String[] hexDigits = {"0", "1", "2", "3",
		                                 "4", "5", "6", "7",
		                                 "8", "9", "a", "b",
		                                 "c", "d", "e", "f"};
	public void testEncrypt(){
		MessageDigest md = null;
		DigestInputStream dis = null;
		String digestedString = null;
		try{
			md = MessageDigest.getInstance("MD5");
			ByteArrayInputStream bis = 
				new ByteArrayInputStream("password".getBytes());
			dis = new DigestInputStream(bis, md);
			
			byte[] bytes = new byte[1024];
			dis.read(bytes);
			md = dis.getMessageDigest();
			dis.close();
			byte[] digest= md.digest();
			
			digestedString =byteArrayToString(digest);
			System.out.println(digestedString);
		} catch (Exception e){
			e.printStackTrace();
			assertTrue(false);
		}
	}
	private String byteToHexString(byte aByte){
		int n = aByte;
		if (n < 0) n = 256 + n;
		int d1 = n/16;
		int d2 = n%16;
		return hexDigits[d1] + hexDigits[d2];
	}
	private String byteArrayToString(byte[] bytes){
		String result = "";
		for (int a = 0; a < bytes.length; a++){
			result += byteToHexString(bytes[a]);
		}
		return result;
	}
}

Not too bad is it?  Thanks to Jamie Jaworski and Paule Perrone for authoring that book (heh, I actually got in on clearance for $15.00) not too shabby...

 

-Aaron