Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Android

Posted by Bill Low
.a{fill-rule:evenodd;}techdegree
Bill Low
Python Web Development Techdegree Student 1,963 Points

Volley> sending GET Request with parameters - How to flatten Map<String,String> parameters correctly into a query string

I got this custom volley request class that extends Request with the request parameters in Map<String,String> format, my question is how to flatten Map<String,String> parameters correctly into a query string and receive it with PHP $_GET?

public class GsonGetRequest_Exp5<T> extends Request<T> {

private Response.Listener<T> listener;
private Map<String, String> params;
private Type type;
private Gson gson;

public GsonGetRequest_Exp5(String url, Map<String, String> params, Type type, Gson gson,
                           Response.Listener<T> reponseListener, Response.ErrorListener errorListener) {
    super(Method.GET, url, errorListener);
    this.type       = type;
    this.gson       = gson;
    this.listener   = reponseListener;
    this.params     = params;
}

public GsonGetRequest_Exp5(int method, String url, Map<String, String> params, Type type, Gson gson,
                           Response.Listener<T> reponseListener, Response.ErrorListener errorListener) {
    super(method, url, errorListener);
    this.type       = type;
    this.gson       = gson;
    this.listener   = reponseListener;
    this.params     = params;
}

@Override
protected Map<String, String> getParams() throws com.android.volley.AuthFailureError {
    return params;
};

@Override
protected void deliverResponse(T response) {
    listener.onResponse(response);
}

@Override
protected Response<T> parseNetworkResponse(NetworkResponse response) {
    try {
        String jsonString = new String(response.data,
                HttpHeaderParser.parseCharset(response.headers));
        return (Response<T>) Response.success
                (
                        gson.fromJson(jsonString, type),
                HttpHeaderParser.parseCacheHeaders(response)
        );
    } catch (UnsupportedEncodingException e) {
        return Response.error(new ParseError(e));
    } catch (JsonSyntaxException je) {
        return Response.error(new ParseError(je));
    }
}

}

public static GsonGetRequest_Exp5<ArrayList<FeedObject>> gsonGetRequest_exp6
(
        Response.Listener<ArrayList<FeedObject>> listener,
        Response.ErrorListener errorListener,
        String str
)
{
    //final String url = "http://example.com/php.php";

    final Map<String, String> params = new HashMap<String, String>();
    final Gson gson = new GsonBuilder()
            .registerTypeAdapter(FeedObject.class, new FeedObjectDeserializer())
            .create();


    String test_url = "http://example.com/php.php";

    params.put("SearchKey", str);




    StringBuilder builder = new StringBuilder();

    for (String key : params.keySet())
    {
        Object value = params.get(key);
        if (value != null)
        {
            try
            {
                value = URLEncoder.encode(String.valueOf(value), HTTP.UTF_8);


                if (builder.length() > 0)
                    builder.append("&");
                builder.append(key).append("=").append(value);
            }
            catch (UnsupportedEncodingException e)
            {
            }
        }
    }

    test_url += "?" + builder.toString();




    return new GsonGetRequest_Exp5
            (
                    test_url,
                    params,
                    new TypeToken<ArrayList<FeedObject>>() {}.getType(),
                    gson,
                    listener,
                    errorListener
            );
}