volley post request issue

Question

I'm not an Android / Java developer but I need to fix this problem in an open source project.

I encountered the error "E / Volley: [300] BasicNetwork.performRequest" while submitting the request and no further explanation was given for this error.

btnSubmit.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        String URL ="http://someURL/api/crm/check_login";
        Response.Listener<String> listener = new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                // LOG Response Or ... 
            }
        };           
        StringRequest request = new StringRequest(Request.Method.POST, URL, listener, errorListener)
        {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {    
                Map<String, String> params = new HashMap<>();
                params.put("username","TEST");
                params.put("password","123456");
                return  params;    
            }
        };                        
        AppController.getInstance().addToRequestQueue(request);    
    });
}

Answer 1

You need to add Content-Type to the header.

@Override
public Map<String, String> getHeaders() throws AuthFailureError {
    HashMap<String, String> headers = new HashMap<String, String>();
    headers.put("Content-Type", "application/json; charset=utf-8");
    return headers;
}