How to send string array in url as x-www-form-urlencoded format?

Question

I want to send multiple values in one key, like sendTo[] -string array and values comma separated in that like abcd@gmail.com,pqrs@gmail.com.

This I tried to achieve using string builder, appended all values using comma separated and then add the builder in hash map with the key.

Like this :

 StringBuilder emailbuilder = new StringBuilder();
                    for (String mail : mEmailList) {

                        emailbuilder.append(mail+",");
                        i++;
                    }

    data.put("send_to[]", emailbuilder.toString());

So it results in hashmap as abcd@gmail.com,pqrs@gmail.com, -- string like this gets added as value for key send_to[].

Later, the type of data sending is x-www-form-urlencoded, so I am converting data into that format.

function to convert :

 private String getDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
    StringBuilder result = new StringBuilder();
    boolean first = true;
    for (Map.Entry<String, String> entry : params.entrySet()) {
        if (first)
            first = false;
        else
            result.append("&");
        result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
        result.append("=");
        result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
    }
    return result.toString();
}

But, after converting it converts the values too. The send_to[] key , value becomes like ---&send_to%5B%5D=realdammy%40hotmail.com%2Csiddhijambhale%40gmail.com%2C

It converts brackets and comma into % format. I need to send data like --- send_to key and value abcd@gmail.com,pqrs@gmail.com

How can I achieve this? Please help Thank you...

EDIT: The function to run the request.

public String sendPostRequest(String data) {

    try {

        URL url = new URL(api);
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setRequestMethod("POST");
        con.setRequestProperty("content-type", "application/x-www-form-urlencoded");
        con.setDoOutput(true);
        con.setDoInput(true);
        OutputStreamWriter writer = new OutputStreamWriter(con.getOutputStream());

        try {
            writer.write(data);
        } catch (Exception e) {
            Log.e("Exception111", e.toString());
        }

        writer.close();

        int responseCode = con.getResponseCode();
        if (responseCode == HttpURLConnection.HTTP_OK || responseCode == HttpURLConnection.HTTP_CREATED) {
            StringBuilder sb = new StringBuilder();
            BufferedReader reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String line = "";
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
            reader.close();
            Log.d("ServerResponse", new String(sb));
            String output = new String(sb);
            return output;
        } else {
            Log.e("Exception", "" + responseCode);
        }
    }
    catch(IOException e)
    {
        Log.e("Exception", "" + e.toString());
    }
    return null;
}

Answer 1

As you are sending the values in a GET request, what you are trying to achieve is not possible. The values will be anyway encoded into % forms to be sent with a GET request. It can be only done if you send the values in a POST request.

To answer in the current context, You need to do a URLDecode at the backend to get the values in that form.

It's a very normal thing and may doesn't even required any additional backend programming. You should receive the same abcd@gmail.com,pqrs@gmail.com easily

Let me know if this worked...

EDIT 1:

Normally we use libraries like Volley for these stuffs..

But to do this with HttpURLConnection, use the following method to prepare Data String

private String getDataString(HashMap<String, String> params) throws UnsupportedEncodingException {
    StringBuilder result = new StringBuilder();
    boolean first = true;
    for (Map.Entry<String, String> entry : params.entrySet()) {
        if (first)
            first = false;
        else
            result.append("\n");
        result.append(entry.getKey());
        result.append(":");
        result.append(entry.getValue());
    }
    return result.toString();
}

Use the following method to add email to the data

data.put("sent_to", TextUtils.join(",",mEmailList));

Keep me posted...

Answer 2

You can use volley https://github.com/google/volley.

String tag_json_obj = "json_obj_req";

String url = "your url";

ProgressDialog pDialog = new ProgressDialog(this);
pDialog.setMessage("Loading...");
pDialog.show();     

        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Method.GET,
                url, null,
                new Response.Listener<JSONObject>() {

                    @Override
                    public void onResponse(JSONObject response) {
                        Log.d(TAG, response.toString());
                        pDialog.hide();
                    }
                }, new Response.ErrorListener() {

                    @Override
                    public void onErrorResponse(VolleyError error) {
                        VolleyLog.d(TAG, "Error: " + error.getMessage());
                        pDialog.hide();
                    }
                }) {

            @Override
            protected Map<String, String> getParams() {
                Map<String, String> params = new HashMap<String, String>();

                params.put("send", "abc@gmail.info,abc1@gmail.info");
                params.put("password", "password123");

                return params;
            }

        };

// Adding request to request queue
AppController.getInstance().addToRequestQueue(jsonObjReq, tag_json_obj);