package com.nationalelectric.greenH5.identityAuth.util.devon.secure;

import com.nationalelectric.greenH5.identityAuth.util.devon.HexUtils;

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

/**
 * MD5工具类
 *
 * TODO: 2017/8/14  重构为Hash接口digest方法，提供MD5, SHA1, SHA256等实现类
 *
 * @author <a href="mailto:93785732@qq.com">ZhengDaHong@fzfx</a>
 * @since 2017/5/2 11:18
 */
public class Md5Utils {

	public static final String HASH_ALGORITHM_NAME = "MD5";

	private static final String CHAR_ENCODING = "UTF-8";


	/**
	 * 对传入的字符串做MD5哈希处理，返回大写结果
	 *
	 * @param source
	 * @return
	 */
	public static String md5WithUpperCase(String source) {
		return md5(source, false);
	}

	/**
	 * 对传入的字符串做MD5哈希处理，返回小写结果
	 *
	 * @param source
	 * @return
	 */
	public static String md5WithLowerCase(String source) {
		return md5(source, true);
	}

	/**
	 * 对传入的字符串做MD5哈希处理
	 *
	 * @param source
	 * @param useLowerCase
	 * @return
	 */
	private static String md5(String source, boolean useLowerCase) {
		try {
			MessageDigest md5 = MessageDigest.getInstance(HASH_ALGORITHM_NAME);
			return HexUtils.encode(md5.digest(source.getBytes(CHAR_ENCODING)), useLowerCase);
		} catch (NoSuchAlgorithmException e) {
			// Formalization, should not occurs actually.
			throw new IllegalStateException("No such algorithm which named 'MD5'", e);
		} catch (UnsupportedEncodingException e) {
			throw new IllegalStateException("Unsupported encoding named 'UTF-8'", e);
		}
	}

}