一个md5类

package com.nj.secret.tools;


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


public class MD5Tool {


public static String md5(String string) {
   byte[] hash;
   try {
       hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8"));
   } catch (NoSuchAlgorithmException e) {
       throw new RuntimeException("Huh, MD5 should be supported?", e);
   } catch (UnsupportedEncodingException e) {
       throw new RuntimeException("Huh, UTF-8 should be supported?", e);
   }


   StringBuilder hex = new StringBuilder(hash.length * 2);
   for (byte b : hash) {
       if ((b & 0xFF) < 0x10) hex.append("0");
       hex.append(Integer.toHexString(b & 0xFF));
   }
   return hex.toString();
}
}