/*
 *
 * Copyright (c) 2001-2019 泛微软件.
 * 泛微协同商务系统,版权所有.
 *
 */
package com.weaver.esb.util;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.security.MessageDigest;

/**
 * <p>Title: ${file_name}</p>
 * <p>Description: </p>
 *
 * @author SJZ
 * @date 2019/12/5
 * @version 1.0
 *
 */
public class EncoderHandler {
    private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5',
            '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

    private static Logger logger = LoggerFactory.getLogger(EncoderHandler.class);
    /**
     * encode string
     *
     * @param algorithm
     * @param str
     * @return String
     */
    public static String encode(String algorithm, String str) {
        if (str == null) {
            return null;
        }
        try {
            MessageDigest messageDigest = MessageDigest.getInstance(algorithm);
            messageDigest.update(str.getBytes());
            return getFormattedText(messageDigest.digest());
        } catch (Exception e) {
            logger.error(e.getMessage());
            return null;
        }
    }

    /**
     * Takes the raw bytes from the digest and formats them correct.
     *
     * @param bytes
     *            the raw bytes from the digest.
     * @return the formatted bytes.
     */
    private static String getFormattedText(byte[] bytes) {
        int len = bytes.length;
        StringBuilder buf = new StringBuilder(len * 2);
        // 把密文转换成十六进制的字符串形式
        for (int j = 0; j < len; j++) {
            buf.append(HEX_DIGITS[(bytes[j] >>> 4) & 0X0F]);
            buf.append(HEX_DIGITS[bytes[j] & 0X0F]);
        }
        return buf.toString();
    }
}