private static String RemoveSpecialCharacters(String str) {
		char[] buffer = new char[str.length()];
		int idx = 0;

		for (int i = 0; i < str.length(); i++) {
			char c = str.charAt(i);

			if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c == '.') || (c == '_')) {
				buffer[idx] = c;
				idx++;
			}
		}

		return new String(buffer, 0, idx);
	}