Java信息摘要

java信息摘要的代碼

import java.util.List;
import java.util.ArrayList;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
                      
public class TestMessageDigest {
    public static void main(String[] args){
        String  input = "012345678901234567890123456789";
        //String  input = "0123456789012345678901234567890123456789123456789";
                      
        try{          
            byte[] hash = getHash(input);
            String hash_str = byte2hex(hash);
            System.out.println(hash_str);
                      
        }catch(NoSuchAlgorithmException e){ 
            e.printStackTrace();
        }             
                      
    }                 
    //對輸入字符串做信息摘要                                                                                                                                           
    private static byte[] getHash(String in) throws NoSuchAlgorithmException {
        System.out.println(in);
        MessageDigest md = MessageDigest.getInstance("MD5");//MD5,SHA-1,SHA-256等
        md.update(in.getBytes());
        return md.digest();
    }                 
    //byte轉16進制字符串
    private static String byte2hex(byte[] b)
    {                 
        String hs="";
        String stmp="";
        for (int n=0;n<b.length;n++)
        {             
            stmp=(java.lang.Integer.toHexString(b[n] & 0XFF));
            if (stmp.length()==1) hs=hs+"0"+stmp;
            else hs=hs+stmp;
        }             
        return hs.toUpperCase();
    }                 
}