Parsing query strings on Android

Question

Java EE has ServletRequest.getParameterValues().

On non-EE platforms, URL.getQuery() simply returns a string.

What\'s the normal way to properly parse the qu

Answer 1

Just for reference, this is what I've ended up with (based on URLEncodedUtils, and returning a Map).

Features:

• it accepts the query string part of the url (you can use request.getQueryString())
• an empty query string will produce an empty Map
• a parameter without a value (?test) will be mapped to an empty List

Code:

public static Map> getParameterMapOfLists(String queryString) {
    Map> mapOfLists = new HashMap>();
    if (queryString == null || queryString.length() == 0) {
        return mapOfLists;
    }
    List list = URLEncodedUtils.parse(URI.create("http://localhost/?" + queryString), "UTF-8");
    for (NameValuePair pair : list) {
        List values = mapOfLists.get(pair.getName());
        if (values == null) {
            values = new ArrayList();
            mapOfLists.put(pair.getName(), values);
        }
        if (pair.getValue() != null) {
            values.add(pair.getValue());
        }
    }

    return mapOfLists;
}

A compatibility helper (values are stored in a String array just as in ServletRequest.getParameterMap()):

public static Map getParameterMap(String queryString) {
    Map> mapOfLists = getParameterMapOfLists(queryString);

    Map mapOfArrays = new HashMap();
    for (String key : mapOfLists.keySet()) {
        mapOfArrays.put(key, mapOfLists.get(key).toArray(new String[] {}));
    }

    return mapOfArrays;
}