public static String urlDecode(final String value) {
        if (value == null) {
            return null;
        }

        try {
            return URLDecoder.decode(value, DEFAULT_ENCODING);

        } catch (UnsupportedEncodingException ex) {
            throw new RuntimeException(ex);
        }
    }
Decode a string for use in the path of a URL; uses URLDecoder.decode,
which decodes a string for use in the query portion of a URL.

@param value The value to decode
@return The decoded value if parameter is not null, otherwise, null is returned.
aws-java-sdk-core/src/main/java/com/amazonaws/util/SdkHttpUtils.java