SecretUtils.java

package com.meishu.util;

import org.apache.commons.codec.binary.Hex;

import java.math.BigInteger;
import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.util.Random;
import java.util.UUID;

public class SecretUtils {

    /**
     * 对用户登录密码进行MD5加密
     *
     * @param str
     * @return
     */

    public static String getMD5String(String str) {
        try {
            // 生成一个MD5加密计算摘要
            MessageDigest md = MessageDigest.getInstance("MD5");
            // 计算md5函数
            md.update(str.getBytes());
            // digest()最后确定返回md5 hash值，返回值为8位字符串。因为md5 hash值是16位的hex值，实际上就是8位的字符
            // BigInteger函数则将8位的字符串转换成16位hex值，用字符串来表示；得到字符串形式的hash值
            //一个byte是八位二进制，也就是2位十六进制字符（2的8次方等于16的2次方）
            return new BigInteger(1, md.digest()).toString(16);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 对字符串进行SHA加密
     *
     * @param
     */
    public static String getSHAString(String str) {
        try {
            MessageDigest sha = MessageDigest.getInstance("SHA-1");

            byte[] byteArray = str.getBytes(StandardCharsets.UTF_8);
            byte[] md5Bytes = sha.digest(byteArray);
            StringBuffer hexValue = new StringBuffer();
            for (int i = 0; i < md5Bytes.length; i++) {
                int val = ((int) md5Bytes[i]) & 0xff;
                if (val < 16) {
                    hexValue.append("0");
                }
                hexValue.append(Integer.toHexString(val));
            }

            return hexValue.toString();
        } catch (Exception e) {
            return null;
        }

    }


    private static byte[] md5(String s)
    {
        MessageDigest algorithm;
        try
        {
            algorithm = MessageDigest.getInstance("MD5");
            algorithm.reset();
            algorithm.update(s.getBytes("UTF-8"));
            byte[] messageDigest = algorithm.digest();
            return messageDigest;
        }
        catch (Exception e)
        {

        }
        return null;
    }

    private static final String toHex(byte hash[])
    {
        if (hash == null)
        {
            return null;
        }
        StringBuffer buf = new StringBuffer(hash.length * 2);
        int i;

        for (i = 0; i < hash.length; i++)
        {
            if ((hash[i] & 0xff) < 0x10)
            {
                buf.append("0");
            }
            buf.append(Long.toString(hash[i] & 0xff, 16));
        }
        return buf.toString();
    }

    public static String hash(String s)
    {
        try
        {
            return new String(toHex(md5(s)).getBytes("UTF-8"), "UTF-8");
        }
        catch (Exception e)
        {
            return s;
        }
    }

    public static void main(String[] args) {
        String uuid = UUID.randomUUID().toString();
        System.out.println(uuid);
        System.out.println(hash(uuid+"ixihs"));
    }
}