回复Android中的现有评论系统

So we have a comment system in our application, and now we want to be able to add replies to specific comments, like a Facebook wall.

Our Java method for posting a comment:

class PostComment extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(AddCommentActivity.this);
        pDialog.setMessage("Posting Comment...");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    @Override
    protected String doInBackground(String... args) {
        // TODO Auto-generated method stub
         // Check for success tag
        int success;
        String post_title = title.getText().toString();
        String post_message = message.getText().toString();

        //We need to change this:
        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(AddCommentActivity.this);
        String post_username = sp.getString("username", "anon");

        try {
            // Building Parameters
            List<NameValuePair> params = new ArrayList<>();
            params.add(new BasicNameValuePair("username", post_username));
            params.add(new BasicNameValuePair("title", post_title));
            params.add(new BasicNameValuePair("message", post_message));

            Log.d("request!", "starting");

            //Posting user data to script 
            JSONObject json = jsonParser.makeHttpRequest(
                    POST_COMMENT_URL, "POST", params);

            // full json response
            Log.d("Post Comment attempt", json.toString());

            // json success element
            success = json.getInt(TAG_SUCCESS);
            if (success == 1) {
                Log.d("Comment Added!", json.toString());    
                finish();
                return json.getString(TAG_MESSAGE);
            }else{
                Log.d("Comment Failure!", json.getString(TAG_MESSAGE));
                return json.getString(TAG_MESSAGE);

            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;

    }

    protected void onPostExecute(String file_url) {
        // dismiss the dialog once product deleted
        pDialog.dismiss();
        if (file_url != null){
            Toast.makeText(AddCommentActivity.this, file_url, Toast.LENGTH_LONG).show();
        }
    }
}
}

and our PHP to send to MySQL:

<?php

//load and connect to MySQL database stuff
require("config.inc.php");
$query_params=null;

if (!empty($_POST)) {
    //initial query
    $query = "INSERT INTO comments ( username, title, message ) VALUES (   :user, :title, :message ) ";

     //Update query
    $query_params = array(
        ':user' => $_POST['username'],
        ':title' => $_POST['title'],
         ':message' => $_POST['message']
    );

    //execute query
    try {
        $stmt   = $db->prepare($query);
        $result = $stmt->execute($query_params);
    }
     catch (PDOException $ex) {
        // For testing, you could use a die and message. 
        //die("Failed to run query: " . $ex->getMessage());

       //or just use this use this one:
        $response["success"] = 0;
        $response["message"] = "Database Error. Couldn't add post!";
        die(json_encode($response));
    }

    $response["success"] = 1;
    $response["message"] = "Post Successfully Added!";
    //echo json_encode($response);

} else {
?>

I've made a new table in MySQL called replies which has:

reply_id (INT AI)
reply_content (text)
reply_postid (INT)
reply_byusername (varchar)

I'm guessing somehow we make an arraylist that picks the commentid from the original comment and we can chain that to replies, but I don't know how. I generally have no idea how to proceed from here.