Volley JsonObjectRequest Post parameters no longer work

Question

I am trying to send POST parameters in a Volley JsonObjectRequest. Initially, it was working for me by following what the official code says to do of passing a JSONObject containing the parameters in the constructor of the JsonObjectRequest. Then all of a sudden it stopped working and I haven't made any changes to the code that was previously working. The server no longer recognizes that any POST parameters are being sent. Here is my code:

RequestQueue queue = Volley.newRequestQueue(this);
String url ="http://myserveraddress";

// POST parameters
Map<String, String> params = new HashMap<String, String>();
params.put("tag", "test");

JSONObject jsonObj = new JSONObject(params);

// Request a json response from the provided URL
JsonObjectRequest jsonObjRequest = new JsonObjectRequest
        (Request.Method.POST, url, jsonObj, new Response.Listener<JSONObject>()
        {
            @Override
            public void onResponse(JSONObject response)
            {
                Toast.makeText(getApplicationContext(), response.toString(), Toast.LENGTH_SHORT).show();
            }
        },
        new Response.ErrorListener()
        {
            @Override
            public void onErrorResponse(VolleyError error)
            {
                Toast.makeText(getApplicationContext(), error.toString(), Toast.LENGTH_SHORT).show();
            }
        });

// Add the request to the RequestQueue.
queue.add(jsonObjRequest);

Here is the simple tester PHP code on the server:

$response = array("tag" => $_POST["tag"]);
echo json_encode($response);

The response I get is {"tag":null}
Yesterday, it worked fine and was responding with {"tag":"test"}
I haven't changed a single thing, but today it is no longer working.

In the Volley source code constructor javadoc it says that you can pass a JSONObject in the constructor to send post parameters at "@param jsonRequest": https://android.googlesource.com/platform/frameworks/volley/+/master/src/main/java/com/android/volley/toolbox/JsonObjectRequest.java

/**
 * Creates a new request.
 * @param method the HTTP method to use
 * @param url URL to fetch the JSON from
 * @param jsonRequest A {@link JSONObject} to post with the request. Null is allowed and
 *       indicates no parameters will be posted along with request.

I have read other posts with similar questions, but the solutions haven't worked for me:

Volley JsonObjectRequest Post request not working

Volley Post JsonObjectRequest ignoring parameters while using getHeader and getParams

Volley not sending a post request with parameters.

I've tried setting the JSONObject in the JsonObjectRequest constructor to null, then overriding and setting the parameters in the "getParams()", "getBody()", and "getPostParams()" methods, but none of those overrides has worked for me. Another suggestion was to use an additional helper class that basically creates a custom request, but that fix is a bit too complex for my needs. If it comes down to it I will do anything to make it work, but I am hoping that there is a simple reason as to why my code was working, and then just stopped, and also a simple solution.

Answer 1

You just have to make a JSONObject from your HashMap of parameters:

String url = "https://www.youraddress.com/";

Map<String, String> params = new HashMap();
params.put("first_param", 1);
params.put("second_param", 2);

JSONObject parameters = new JSONObject(params);

JsonObjectRequest jsonRequest = new JsonObjectRequest(Request.Method.POST, url, parameters, new Response.Listener<JSONObject>() {
    @Override
    public void onResponse(JSONObject response) {
        //TODO: handle success
    }
}, new Response.ErrorListener() {
    @Override
    public void onErrorResponse(VolleyError error) {
        error.printStackTrace();
        //TODO: handle failure
    }
});

Volley.newRequestQueue(this).add(jsonRequest);