/**
 * Copyright 2021 Tianmian Tech. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.welab.wefe.serving.service.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 参数拼接的字符串
	 * @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 | UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return encodeStr;
	}

	/**
	 * 将byte转为16进制
	 *
	 * @param bytes
	 * @return
	 */
	private static String byte2Hex(byte[] bytes) {
		StringBuilder sb = new StringBuilder();
		String temp = null;
		for (byte aByte : bytes) {
			temp = Integer.toHexString(aByte & 0xFF);
			if (temp.length() == 1) {
				// 1得到一位的进行补0操作
				sb.append("0");
			}
			sb.append(temp);
		}
		return sb.toString();
	}
}
