MD5 生成32位或16位字符串

package com.necsthz.questionnaire.util;

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

    public class MD5 {

public static String createID (String key) throws NoSuchAlgorithmException {
key = String.valueOf(System.currentTimeMillis()) + key ; 
StringBuffer buf = null ;
try {
              MessageDigest md = MessageDigest.getInstance("MD5");
              md.update(key.getBytes());
              byte b[] = md.digest();
              int i;
              buf = new StringBuffer("");
              for (int offset = 0; offset < b.length; offset++) {
                      i = b[offset];
                      if (i < 0)
                      i += 256;
                      if (i < 16)
                      buf.append("0");
                      buf.append(Integer.toHexString(i));
              }
                } catch (NoSuchAlgorithmException e) {
               e.printStackTrace();
      }
  return  buf.toString().substring(8, 24); // 16位的加密
//    return buf.toString());// //         32位的加密

}

/**
* @param args
*/
public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
System.out.println(MD5.createID("test"));
}

}

评论

1 楼 boosi 2014-03-21  

public static void main(String[] args) throws Exception {
// TODO Auto-generated method stub
System.out.println(MD5.createID("test"));