HttpServletRequest - Get query string parameters, no form data

Question

In HttpServletRequest, getParameterMap returns a Map of all query string parameters and post data parameters.

Is there a way to get a Map of ONLY query

Answer 1

As the other answers state there is no way getting query string parameters using servlet api.

So, I think the best way to get query parameters is parsing the query string yourself. ( It is more complicated iterating over parameters and checking if query string contains the parameter)

I wrote below code to get query string parameters. Using apache StringUtils and ArrayUtils which supports CSV separated query param values as well.

Example: username=james&username=smith&password=pwd1,pwd2 will return

password : [pwd1, pwd2] (length = 2)

username : [james, smith] (length = 2)

public static Map getQueryParameters(HttpServletRequest request) throws UnsupportedEncodingException {
    Map queryParameters = new HashMap<>();
    String queryString = request.getQueryString();
    if (StringUtils.isNotEmpty(queryString)) {
        queryString = URLDecoder.decode(queryString, StandardCharsets.UTF_8.toString());
        String[] parameters = queryString.split("&");
        for (String parameter : parameters) {
            String[] keyValuePair = parameter.split("=");
            String[] values = queryParameters.get(keyValuePair[0]);
            //length is one if no value is available.
            values = keyValuePair.length == 1 ? ArrayUtils.add(values, "") :
                    ArrayUtils.addAll(values, keyValuePair[1].split(",")); //handles CSV separated query param values.
            queryParameters.put(keyValuePair[0], values);
        }
    }
    return queryParameters;
}