how to hash an password using MD5

import java.security.MessageDigest;
import java.security.Security;
import java.security.NoSuchAlgorithmException;
import java.io.UnsupportedEncodingException;

public class HelloWorld{
    public static String ConvertToHash(String password)
	{
		try {
			MessageDigest ms = MessageDigest.getInstance("MD5");
			byte[] pass = password.getBytes();
			byte[] byteData = ms.digest(password.getBytes("UTF-8"));
			StringBuffer sb = new StringBuffer();
            for (int i = 0; i < byteData.length; i++) {
             sb.append(Integer.toString((byteData[i] & 0xff) + 0x100, 16).substring(1));
            }
			return sb.toString();
		} catch (NoSuchAlgorithmException e) {
			return null;
		} catch (UnsupportedEncodingException e) {
			return null;
		}
	}
     
     public static void main(String []args){
        System.out.println(ConvertToHash("password"));
        System.out.println(ConvertToHash("password"));
     }
}