字符串和十六进制互转

/**
 * 字符串转换为16进制字符串
 *
 * @param s
 * @return
 */
public static String stringToHexString(String s) {
    String str = "";
    for (int i = 0; i < s.length(); i++) {
        int ch = (int) s.charAt(i);
        String s4 = Integer.toHexString(ch);
        str = str + s4;
    }
    return str;
}

/**
 * 16进制字符串转换为字符串
 *
 * @param s
 * @return
 */
public static String hexStringToString(String s) {
    if (s == null || s.equals("")) {
        return null;
    }
    s = s.replace(" ", "");
    byte[] baKeyword = new byte[s.length() / 2];
    for (int i = 0; i < baKeyword.length; i++) {
        try {
            baKeyword[i] = (byte) (0xff & Integer.parseInt(
                    s.substring(i * 2, i * 2 + 2), 16));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    try {
        s = new String(baKeyword, "gbk");
        new String();
    } catch (Exception e1) {
        e1.printStackTrace();
    }
    return s;
}