常见的MD5和Base64加密

日常我们在项目中常用到加密，所以我整理一下我在项目中用到的加密方法，特意写了一个工具类来分享：

/**
 * Created by Fengwei on 2016/6/20.
 */

/**
 * 加密工具类
 */
public class EncryptionAndDecryptUtil {
    private final static char hexDigits[]={"0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"};
    private static char[] base64EncodeChars = new char[] { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P",
            "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o",
            "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "+", "/" };

    private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
            -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55,
            56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
            21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46,
            47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };
    /**
     * MD5加密
     * @param text
     * @return String
     */
    public static String EncryptionByMD5(String text){
        try {
            byte[] btInput = text.getBytes();
            // 获得MD5摘要算法的 MessageDigest 对象
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            // 使用指定的字节更新摘要
            mdInst.update(btInput);
            // 获得密文
            byte[] md = mdInst.digest();
            // 把密文转换成十六进制的字符串形式
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }

    }
    /**
     * MD5加密
     * @param text
     * @return byte[]
     */
    public static byte[] EncryptionByMD5T(String text){
        try {
            byte[] btInput = text.getBytes();
            // 获得MD5摘要算法的 MessageDigest 对象
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            // 使用指定的字节更新摘要
            mdInst.update(btInput);
            // 获得密文
            byte[] md = mdInst.digest();

            return md;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }

    }
    /**
     * Base64加密
     * @param text
     * @return String
     */
    public static String EncryptionByBase64(String text) {
        byte[] data=text.getBytes();
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;

        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }

    /**
     * Base64加密
     * @param data
     * @return String
     */
    public static String EncryptionByBase64(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;

        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len) {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }


    /**
     * 先MD5加密，再base64加密
     * @param text
     * @return String
     */
    public static String EncryptionByMD5AndBase64(String text){

      return EncryptionByBase64(EncryptionByMD5T(text));
    }

    /**
     * Base64 解密
     * @return String
     */
    public static String decryptBase64(String text){
        byte[] data = text.getBytes();
        int len = data.length;
        ByteArrayOutputStream buf = new ByteArrayOutputStream(len);
        int i = 0;
        int b1, b2, b3, b4;

        while (i < len)
        {

            /* b1 */
            do
            {
                b1 = base64DecodeChars[data[i++]];
            }
            while (i < len && b1 == -1);
            if (b1 == -1)
            {
                break;
            }

            /* b2 */
            do
            {
                b2 = base64DecodeChars[data[i++]];
            }
            while (i < len && b2 == -1);
            if (b2 == -1)
            {
                break;
            }
            buf.write((int) ((b1 << 2) | ((b2 & 0x30) >>> 4)));

            /* b3 */
            do
            {
                b3 = data[i++];
                if (b3 == 61)
                {
                    return new String(buf.toByteArray());
                }
                b3 = base64DecodeChars[b3];
            }
            while (i < len && b3 == -1);
            if (b3 == -1)
            {
                break;
            }
            buf.write((int) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));

            /* b4 */
            do
            {
                b4 = data[i++];
                if (b4 == 61)
                {
                    return new String(buf.toByteArray());
                }
                b4 = base64DecodeChars[b4];
            }
            while (i < len && b4 == -1);
            if (b4 == -1)
            {
                break;
            }
            buf.write((int) (((b3 & 0x03) << 6) | b4));
        }
        return new String(buf.toByteArray());
    }

    /**
     * 网络传输中文UTF-8加密，防止乱码
     * @param text
     * @return String
     */
    public static String netEnCoderUTF8(String text){
        return netEnCoder(text,"UTF-8");
    }

    /***
     * 网络传输中文UTF-8解码
     * @param text
     * @return String
     */
    public static String netEDeCoderUTF8(String text){
        return netDecoder(text,"UTF-8");
    }


    /**
     *
     * @param text
     * @param charsetName 字符集
     * @return String
     */
    public static String netEnCoder(String text,String charsetName){
        String result=null;
        try {
            result= URLEncoder.encode(text,charsetName);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     *
     * @param text
     * @param charsetName 字符集
     * @return String
     */
    public static String netDecoder(String text,String charsetName){
        String result=null;
        try {
            result= URLDecoder.decode(text,charsetName);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return result;
    }
}