package com.miniframe.utils;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA256Utils {
  
    /**
     * 利用java原生的类实现SHA256加密
     * @param str 加密后的报文
     * @return
     */
    public static String getSHA256(String str){
       MessageDigest messageDigest;
        String encodestr = "";
        try {
       messageDigest = MessageDigest.getInstance("SHA-256");
       messageDigest.update(str.getBytes("UTF-8"));
       encodestr = byte2Hex(messageDigest.digest());
        } catch (NoSuchAlgorithmException e) {
       e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
       e.printStackTrace();
        }
        return encodestr;
    }
    /**
     * 将byte转为16进制
     * @param bytes
     * @return
     */
    private static String byte2Hex(byte[] bytes){
        StringBuffer stringBuffer = new StringBuffer();
        String temp = null;
        for (int i=0;i<bytes.length;i++){
         temp = Integer.toHexString(bytes[i] & 0xFF);
         if (temp.length()==1){
         //1得到一位的进行补0操作
         stringBuffer.append("0");
         }
        stringBuffer.append(temp);
        }
        return stringBuffer.toString();
    }



    public static  String getString(byte[] data ){
        return byte2Hex(data);
    }
    public static byte[] SHA256(byte[] data)
    {
        // 返回值
        byte byteBuffer[] = {};

        try
        {
            // SHA 加密开始
            // 创建加密对象 并傳入加密類型
            MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
            // 传入要加密的字符串
            messageDigest.update(data);
            // 得到 byte 類型结果
            byteBuffer = messageDigest.digest();
            return byteBuffer;
        }
        catch (NoSuchAlgorithmException e)
        {
            e.printStackTrace();
        }
        return byteBuffer;
    }
}