Web API call too slow

Question

I have an android app that most of its feature consumes an API. My client complained that the retrieving of data from the web api is very slow. I wonder what's causing this.

Here's a basic structure of how I do my calls:

String returnString = "";

    token = tokenBuilder.generateToken("Customers/All");

    try {
    HttpGet request = new HttpGet(apiUrl + "CustomerRewards/All?customerId=" + id);
    request.setHeader(HTTP.CONTENT_TYPE, "application/json");
    request.setHeader("AccountId", headerAccountId);
    request.setHeader("StoreId", headerStoreId);
    request.setHeader("AppKey", headerAppKey);
    request.setHeader("Token", token);

    HttpClient client = new DefaultHttpClient();

    HttpResponse response = client.execute(request);
    String responseString = EntityUtils.toString(response.getEntity());

    Log.i("Api Message", responseString);

    returnString = responseString;
    } catch (Exception e) {
        returnString = e.getMessage();
    }

    return returnString;

I'm calling this method from a progress dialog in order to display a loader while, retrieving data from the web API. Is there a better way to do this? Or is somewhat my android code affects its performance?

Here's the code on the calling progress dialog.

rewardsErrorMessage = "";

    progressBar = new ProgressDialog(this);
    progressBar.setCancelable(true);
    progressBar.setMessage("Loading info ...");
    progressBar.setProgressStyle(ProgressDialog.STYLE_SPINNER);
    progressBar.setProgress(0);
    progressBar.setMax(100);
    progressBar.setCancelable(false);
    progressBar.show();

    apiLoadStatus = false;

    new Thread(new Runnable() {
        public void run() {
            while (!apiLoadStatus) {
                apiLoadStatus = RewardApi();
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                        e.printStackTrace();
                      }

                    }
                if (apiLoadStatus) {
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                        progressBar.dismiss();
                    }
                  }}).start();

        progressBar.setOnDismissListener(new OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialog) {
                SetValues();
            }

        });

And here's the method that actually calls the api class that connects to the web api

ApiConnection api = new ApiConnection();

    try {
        Log.i("CustomerId", customerInfos.getString("customer_id", ""));
        transactionMessage = api.GetTransactions(customerInfos.getString("customer_id", ""));
        availableRewardsMessage = api.GetCustomerRewards(customerInfos.getString("customer_id", ""));

        try
        {
            if(transactionMessage.contains("Timestamp"))
            {
                Log.i("Transaction", "Success");
                GetPoints(transactionMessage);
            }
            if(!availableRewardsMessage.equals("[]") && !availableRewardsMessage.equals("[]"))
            {
                JSONObject rewardsJson = new JSONObject(availableRewardsMessage);
                availableRewardsMessage = rewardsJson.getString("AvailableRewards");
                hasRewards = true;
            }
            return true;
        }
        catch(Exception e)
        {
            rewardsErrorMessage = transactionMessage.replace('[', ' ').replace(']', ' ').replace('"', ' ');
        }



    } catch(Exception e) {
        e.printStackTrace();
        rewardsErrorMessage = e.getMessage();
        return true;
    }
    return true;

As you notice, I have two api calls here.

I really would like to speed up the retrieving of data. Or is the api I'm consuming that slow? Any ideas guys? Thanks!

Answer 1

As you're probably aware, there are a number of factors that can affect HTTP service calls, of which the client code is only one:

1. Network speed and latency
2. Server availability and load
3. Size of data payload
4. Client device resources
5. Client code

You really need to determine where the bottleneck(s) are in order to know where to try to optimize. Additionally, you should make sure that the server is using Gzip to compress the payload and add the following to your client code:

request.setHeader("Accept-Encoding", "gzip");