MD5加密类

import java.io.UnsupportedEncodingException;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;public class Md5Util {/**      * MD5 加密      */      public String getMD5Str(String str) {          MessageDigest messageDigest = null;            try {              messageDigest = MessageDigest.getInstance("MD5");                messageDigest.reset();                messageDigest.update(str.getBytes("UTF-8"));          } catch (NoSuchAlgorithmException e) {              System.out.println("NoSuchAlgorithmException caught!");              System.exit(-1);          } catch (UnsupportedEncodingException e) {              e.printStackTrace();          }            byte[] byteArray = messageDigest.digest();            StringBuffer md5StrBuff = new StringBuffer();            for (int i = 0; i < byteArray.length; i++) {                          if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)                  md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));              else                  md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));          }            return md5StrBuff.toString();      }     public static void main(String args[]){      Md5Util md5 = new Md5Util();          System.out.println(md5.getMD5Str("admin"));      }  }