password/src/main/java/Password9.java

/**
 * @author richie
 * @version 10.0
 * Created by richie on 2019-07-12
 */
public class Password9 {

    private static final int HEX = 16;

    private static final int ENCODE_LEN = 4;

    private static final int[] PASSWORD_MASK_ARRAY = {19, 78, 10, 15, 100, 213, 43, 23};

    /**
     * 给字符串加密.
     *
     * @param text 旧文本
     * @return 加密结果
     */
    public static String passwordEncode(String text) {
        StringBuilder passwordTextBuf = new StringBuilder();
        passwordTextBuf.append("___");
        if (text == null) {
            return passwordTextBuf.toString();
        }

        int pmIndex = 0;
        for (int i = 0; i < text.length(); i++) {
            if (pmIndex == PASSWORD_MASK_ARRAY.length) {
                pmIndex = 0;
            }

            int intValue = ((int) text.charAt(i)) ^ PASSWORD_MASK_ARRAY[pmIndex];
            String passwordText = Integer.toHexString(intValue);
            int pLength = passwordText.length();
            for (int j = 0; j < ENCODE_LEN - pLength; j++) {
                passwordText = "0" + passwordText;
            }

            passwordTextBuf.append(passwordText);
            pmIndex++;
        }

        return passwordTextBuf.toString();
    }

    /**
     * 给字符串解密
     *
     * @param passwordText 待解密的字符串
     * @return 解密后的字符串
     */
    public static String passwordDecode(String passwordText) {
        if (passwordText != null && passwordText.startsWith("___")) {
            passwordText = passwordText.substring(3);

            StringBuilder textBuf = new StringBuilder();

            int pmIndex = 0;
            for (int i = 0; i <= (passwordText.length() - ENCODE_LEN); i += ENCODE_LEN) {
                if (pmIndex == PASSWORD_MASK_ARRAY.length) {
                    pmIndex = 0;
                }

                String hexText = passwordText.substring(i, i + ENCODE_LEN);
                int hexInt = Integer.parseInt(hexText, HEX) ^ PASSWORD_MASK_ARRAY[pmIndex];

                textBuf.append((char) hexInt);
                pmIndex++;
            }

            passwordText = textBuf.toString();
        }
        return passwordText;
    }
}