JAVA 的MD5加密算法简单实现

 

java 代码

package  com.ctgusec.bean;

import  java.security.MessageDigest;
/** */ /**
*
*  @author  zhupan
*  @version  1.0
 */
 public   class  MD5_encrypt   {
 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 [] strTemp  =  s.getBytes();
  MessageDigest mdTemp  =  MessageDigest.getInstance( " MD5 " );
  mdTemp.update(strTemp);
   byte [] md  =  mdTemp.digest();
   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)   {
   return   null ;
 }
}

  public   static   void  main(String[] args)   {
  //  MD5_Test aa = new MD5_Test();
  System.out.print(MD5_encrypt.MD5( " zhupan " ));
}