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);
}
}