MD5加密

import java.security.MessageDigest;public class MD5Util {    public final static String MD5(String s) {        char hexDigits[] = { '0', '1', '2', '3', '4',                             '5', '6', '7', '8', '9',                             'A', 'B', 'C', 'D', 'E', 'F' };        try {            byte[] btInput = s.getBytes();     //获得MD5摘要算法的 MessageDigest 对象            MessageDigest mdInst = MessageDigest.getInstance("MD5");     //使用指定的字节更新摘要            mdInst.update(btInput);     //获得密文            byte[] md = mdInst.digest();     //把密文转换成十六进制的字符串形式            int j = md.length;            char str[] = new char[j * 2];            int k = 0;            for (int i = 0; i < j; i++) {                byte byte0 = md[i];                str[k++] = hexDigits[byte0 >>> 4 & 0xf];                str[k++] = hexDigits[byte0 & 0xf];            }            return new String(str);        }        catch (Exception e) {            e.printStackTrace();            return null;        }    }    public static void main(String[] args) {        System.out.print(MD5Util.MD5("password"));    }}