HashUtil.java

package com.gr.project.util;

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

public class HashUtil {
    
    public static void main(String[] args) {
        System.out.println(md5HexString("qwert"));
    }
	
	public static String md5HexString(String password) {
        MessageDigest md = null;
        String md5 = null;
		try {
			md = MessageDigest.getInstance("MD5");
		
	        md.update(password.getBytes());
	 
	        byte byteData[] = md.digest();
	 
	        //convert the byte to hex format method 2
	        StringBuffer hexString = new StringBuffer();
	    	for (int i=0;i<byteData.length;i++) {
	    		String hex=Integer.toHexString(0xff & byteData[i]);
	   	     	if(hex.length()==1) hexString.append('0');
	   	     	hexString.append(hex);
	    	}
	    	md5 =  hexString.toString();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		return md5;
    }
	
    public static String generateHash(String seed) {
        String toHash = seed;
        MessageDigest md = null;
        byte[] hash = null;
        try {
            md = MessageDigest.getInstance("SHA-512");
            hash = md.digest(toHash.getBytes("UTF-8"));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return convertToHex(hash);
    }

    /**
     * Converts the given byte[] to a hex string.
     * 
     * @param raw
     *            the byte[] to convert
     * @return the string the given byte[] represents
     */
    private static String convertToHex(byte[] raw) {
        StringBuffer sb = new StringBuffer();
        for (int i = 0; i < raw.length; i++) {
            sb.append(Integer.toString((raw[i] & 0xff) + 0x100, 16).substring(1));
        }
        return sb.toString();
    }
}