How to use Android Volley GET method with specified parameter?

I know how to use Volley GET method for login purposes but what if I need to specify a specific "id"? I am passing the "id" of a list item from a remote database to another activity using intent.putExtra. In the next activity, how would I utilize Volleys' GET method to parse and display data from another table using that passed over "id"?

In a browser I can use the following to get a response with a specified url and parameter:

http://localhost/demoapp/fetch.php?pid=2

But I don't know how to pass that url to a Volley request and display the response in a listview. Something like this:

"http://localhost/demoapp/fetch.php?pid=" + pid

Where "pid" would be the passed over string of the corresponding id.

EDIT:PHP Code

    <?php
include_once("config.php");

$query=mysqli_query($con,"SELECT * FROM comments WHERE pid=".$_GET['pid']);

$array;
while($result=mysqli_fetch_assoc($query)){

$array[]=$result;
}

echo json_encode($array);
?>

EDIT 2: JAVA Code Main Activity

    JsonArrayRequest request = new JsonArrayRequest(url+url_file,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(TAG, response.toString()); try {
                            for(int i=0;i<response.length();i++){
                                String pid=response.getJSONObject(i).getString("pid");
                                String name=response.getJSONObject(i).getString("product_name");
                                String img;
                                String thumb = response.getJSONObject(i).getString("product_thumb");
                                String detail = response.getJSONObject(i).getString("product_detail");
                                String rating = response.getJSONObject(i).getString("product_rating");

                                img = response.getJSONObject(i).getString("product_pic");

                                rowdata.add(new ProductRowData(pid,name,img,thumb,detail,rating));
                            }
                        } catch (JSONException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                        adapter=new ProductsAdapter(MainActivity.this, rowdata);
                        list.setAdapter(adapter);
                        dialog.dismiss();
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.d(TAG, "Error: " + error.getMessage());
                dialog.dismiss();
            }
        });

        VolleyController.getInstance().addToRequestQueue(request, tag_json_arry);

When list item is clicked, rest of data is passed over to detail activity using intent.putExtra. What I am then trying to do is, upon clicking on FAB, a list of comments from a different table with that products id should be shown.