Java计算文本MD5加密值的方法示例

import java.security.messagedigest;

import java.security.nosuchalgorithmexception;

public class getmd5 {

   public static void main(string[] args) {

     string a= "123" ;

   system.out.println(getmd5(a));

   }

   /**

    * 获取文本字段的md5值

    * @param txt

    * @return

    */

   public static string getmd5(string txt){

     string rs = "" ;

     string[] hexdigits = { "0" , "1" , "2" , "3" , "4" , "5" , "6" , "7" , "8" , "9" , "a" , "b" , "c" , "d" , "e" , "f" };

     try {

       messagedigest messagedigest = messagedigest.getinstance( "md5" );

       byte [] b = messagedigest.digest(txt.getbytes());

       stringbuffer resultsb = new stringbuffer();

       for ( int i = 0 ; i < b.length; i++) {

         int n = b[i];

         if (n < 0 )

           n = 256 + n;

         int d1 = n / 16 ;

         int d2 = n % 16 ;

         resultsb.append(hexdigits[d1] + hexdigits[d2]);

       }

       rs = resultsb.tostring();

     } catch (nosuchalgorithmexception e) {

       e.printstacktrace();

     }

     return rs;

   }

}