Use this class in your walmart demo app

AwesomeWalmartApp Doc

Here is the list of resources that will be helpful for AwesomeWalmartApp:

Image resources: https://goo.gl/S9YQDP
Method to get URL content during background task: Included in this page.
Model Class for Product : Included in this page (Note: this class contatins method to convert JSON Data Array to List of Products)

Method to fetch data from URL for .java

private String getWebPageContent(String pageLink) {
        InputStream stream = null;
        HttpsURLConnection connection = null;
        String result = null;

        try {
            //this is just to see the loading during api fetch. Never include this in real apps.
            //it simply waits for 5 sec before doing anything.
            Thread.sleep(5000);
            URL urlObject = new URL(pageLink);
            connection = (HttpsURLConnection) urlObject.openConnection();
            // Timeout for reading InputStream arbitrarily set to 3000ms.
            connection.setReadTimeout(3000);
            // Timeout for connection.connect() arbitrarily set to 3000ms.
            connection.setConnectTimeout(3000);
            // For this use case, set HTTP method to GET.
            connection.setRequestMethod("GET");
            // Already true by default but setting just in case; needs to be true since this request
            // is carrying an input (response) body.
            connection.setDoInput(true);
            // Open communications link (network traffic occurs here).
            connection.connect();

            int responseCode = connection.getResponseCode();
            if (responseCode != HttpsURLConnection.HTTP_OK) {
                throw new IOException("HTTP error code: " + responseCode);
            }
            // Retrieve the response body as an InputStream.
            stream = connection.getInputStream();

            if (stream != null) {
                // Converts Stream to String.
                Reader reader = null;
                final int bufferSize = 1024;
                final char[] buffer = new char[bufferSize];
                final StringBuilder out = new StringBuilder();
                reader = new InputStreamReader(stream, "UTF-8");
                for (; ; ) {
                    int rsz = reader.read(buffer, 0, buffer.length);
                    if (rsz < 0)
                        break;
                    out.append(buffer, 0, rsz);
                }
                result = out.toString();
            }
        }catch (IOException e){
            e.printStackTrace();
        }catch (InterruptedException e){
            e.printStackTrace();
        }
        finally {
            // Close Stream and disconnect HTTPS connection.
            if (stream != null) {
                try {
                    stream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (connection != null) {
                connection.disconnect();
            }
        }
        return result;
    }

Product.java

import com.google.gson.Gson;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;

public class Product {
// TODO: 12/20/17 add (implementation 'com.google.code.gson:gson:2.2.4') in your build.gradle file
    //this url will give list of products
    public static String WALMART_PRODUCTS_URL = "https://demo1738991.mockable.io/walmart-products";
    @SerializedName("name")
    @Expose
    private String name;
    @SerializedName("description ")
    @Expose
    private String description;
    @SerializedName("price")
    @Expose
    private float price;
    @SerializedName("imageURL")
    @Expose
    private String imageURL;

    public static List<Product> getProductListFromJsonArray(String jsonProductArray) {
        List<Product> products = new ArrayList<>();

        //create gson object
        Gson gson = new Gson();

        //create list type
        Type productListType = new TypeToken<List<Product>>() {
        }.getType();

        //convert json to list
        try {
            products = gson.fromJson(jsonProductArray, productListType);
        } catch (Exception e) {
            Log.d("Product", "getProductListFromJsonArray: could not convert:" + jsonProductArray);
        }

        return products;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public float getPrice() {
        return price;
    }

    public void setPrice(float price) {
        this.price = price;
    }

    public String getImageURL() {
        return imageURL;
    }

    public void setImageURL(String imageURL) {
        this.imageURL = imageURL;
    }
}