使用java自带加密算法实现文本的md5加密算法

转载请注明出处：http://blog.csdn.net/xiaojimanman/article/details/21456943

       本篇使用Java自带的MessageDigest实现对文本的md5加密算法，具体代码如下：

  /**
  *@Description: 将字符串转化为MD5
  */
 package cn.yicha.novel.util;

 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;

 public class ParseMD5 {

     /**
      * @param str
      * @return
      * @Date: 2013-9-6
      * @Author: lulei
      * @Description:  32位小写MD5
      */
     public static String parseStrToMd5L32(String str){
         String reStr = null;
         try {
             MessageDigest md5 = MessageDigest.getInstance("MD5");
             byte[] bytes = md5.digest(str.getBytes());
             StringBuffer stringBuffer = new StringBuffer();
             for (byte b : bytes){
                 int bt = b&0xff;
                 if (bt < 16){
                     stringBuffer.append(0);
                 }
                 stringBuffer.append(Integer.toHexString(bt));
             }
             reStr = stringBuffer.toString();
         } catch (NoSuchAlgorithmException e) {
             e.printStackTrace();
         }
         return reStr;
     }

     /**
      * @param str
      * @return
      * @Date: 2013-9-6
      * @Author: lulei
      * @Description: 32位大写MD5
      */
     public static String parseStrToMd5U32(String str){
         String reStr = parseStrToMd5L32(str);
         if (reStr != null){
             reStr = reStr.toUpperCase();
         }
         return reStr;
     }

     /**
      * @param str
      * @return
      * @Date: 2013-9-6
      * @Author: lulei
      * @Description: 16位小写MD5
      */
     public static String parseStrToMd5U16(String str){
         String reStr = parseStrToMd5L32(str);
         if (reStr != null){
             reStr = reStr.toUpperCase().substring(8, 24);
         }
         return reStr;
     }

     /**
      * @param str
      * @return
      * @Date: 2013-9-6
      * @Author: lulei
      * @Description: 16位大写MD5
      */
     public static String parseStrToMd5L16(String str){
         String reStr = parseStrToMd5L32(str);
         if (reStr != null){
             reStr = reStr.substring(8, 24);
         }
         return reStr;
     }
 }