MD5编码

 public class MD5 {

     public static String getMD5(String content) {
         try {
             MessageDigest digest = MessageDigest.getInstance("MD5");
             digest.update(content.getBytes());
             return getHashString(digest);

         } catch (NoSuchAlgorithmException e) {
             e.printStackTrace();
         }
         return null;
     }

     private static String getHashString(MessageDigest digest) {
         StringBuilder builder = new StringBuilder();
         for (byte b : digest.digest()) {
             builder.append(Integer.toHexString((b >> 4) & 0xf));
             builder.append(Integer.toHexString(b & 0xf));
         }
         return builder.toString();
     }
 }