java SHA1加密算法

package com.cn.test.rsa;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;

public class GenerServerDigest {
    //生成32位随机数
    public static String generatorRandom(){
        String _RndData;
        int b = 0;
        int a = 0;
        _RndData = "";
        Random r = new Random();
        for (int i = 0; i < 32; i++) {
            a = r.nextInt(26);
            b = (char) (a + 65);
            _RndData += new Character((char) b).toString();
        }
        return _RndData;
    }
    public static void main(String[] args) {
        String ServerDigest = null;
        try{
            //进行SHA1运算 
            char[] HEXCHAR = { '0', '1', '2', '3', '4', '5', '6', '7', 
                    '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; 
            String MsgtoDigest = GenerServerDigest.generatorRandom(); 
            MessageDigest md = null;
            md = MessageDigest.getInstance("SHA1");
            
            byte[] digest = md.digest(MsgtoDigest.getBytes()); 
            
            StringBuilder sb = new StringBuilder(digest.length * 2); 
            for (int i = 0; i < digest.length; i++) { 
                sb.append(HEXCHAR[(digest[i] & 0xf0) >>> 4]); 
                sb.append(HEXCHAR[digest[i] & 0x0f]); 
            } 
            ServerDigest = sb.toString();
        } catch (NoSuchAlgorithmException e){
            e.printStackTrace();
        }
        System.out.println(ServerDigest);
    }
}