import java.security.MessageDigest;

import java.text.NumberFormat;

public class MD5Utils {

    /**

     *

     * 获取字符串加密后结果

     *

     * @param text

     *            需要加密的字符串

     * @return

     */

    public static String md5(String text) {

        return md5(text, null);

    }

    /**

     * 获取字符串加密后结果

     *

     * @param text

     * @param prifix

     * @return

     */

    public static String md5(String text, String prifix) {

        MessageDigest md5 = null;

        try {

            md5 = MessageDigest.getInstance("MD5");

        } catch (Exception e) {

            e.printStackTrace();

            return "";

        }

        if(null!=prifix && !"".endsWith(prifix)){

            text = prifix + text;

        }

        byte[] originalByte = text.getBytes();

        md5.update(originalByte);

        byte[] newByte = md5.digest();

        StringBuilder stringBuilder = new StringBuilder();

        for (int i = 0; i < newByte.length; i++) {

            if ((newByte[i] & 0xff) < 0x10) {

                stringBuilder.append("0");

            }

            stringBuilder.append(Long.toString(newByte[i] & 0xff, 16));

        }

        return stringBuilder.toString().toUpperCase();

    }

    public static String md5(String text, long userId) {

        MessageDigest md5 = null;

        try {

            md5 = MessageDigest.getInstance("MD5");

        } catch (Exception e) {

            e.printStackTrace();

            return "";

        }

        text = formatKey(userId) + text;

        byte[] originalByte = text.getBytes();

        md5.update(originalByte);

        byte[] newByte = md5.digest();

        StringBuilder stringBuilder = new StringBuilder();

        for (int i = 0; i < newByte.length; i++) {

            if ((newByte[i] & 0xff) < 0x10) {

                stringBuilder.append("0");

            }

            stringBuilder.append(Long.toString(newByte[i] & 0xff, 16));

        }

        return stringBuilder.toString().toUpperCase();

    }

    public static void main(String[] args) {

        System.out.println(MD5Utils.md5("admin", "admin"));

        System.out.println(MD5Utils.md5("admin"));

    }

}