dmsl.smartbill.GoogleShoppingAPIHelperClass.java Source code

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Here is the source code for dmsl.smartbill.GoogleShoppingAPIHelperClass.java

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/* 
 ** GoogleShoppingAPIHelperClass.java
 **
 ** Copyright (C) 2012 Kyriakos Georgiou & Kyriakos Frangeskos
 **
 ** This program is free software: you can redistribute it and/or modify
 ** it under the terms of the GNU General Public License as published by
 ** the Free Software Foundation, either version 3 of the License, or
 ** at your option) any later version.
 **
 ** This program is distributed in the hope that it will be useful,
 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 ** GNU General Public License for more details.
 **
 ** You should have received a copy of the GNU General Public License
 ** along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package dmsl.smartbill;

import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

/**
 * 
 * @author Kyriakos Georgiou
 * @author Kyriakos Frangeskos
 * 
 * This class implements 2 methods that retrieve a information from
 * the Google Shopping API via an HTTP request and by parsing a 
 * JSON Object.
 *
 */
public class GoogleShoppingAPIHelperClass {

    private String SHOPPING_API_KEY = "ENTER YOUR GOOGLE SEARCH API FOR SHOPPING KEY HERE";

    /**
     * Sends an HTTP request to Google API for Shopping and retrieves a JSON
     * String of a product, based on the barcode number given in the search
     * criteria.
     * 
     * @param barcodeContents
     *            The product's barcode which we use to find that product.
     * @return The JSON String that holds information about the product.
     */
    private String getJsonStringFromGoogleShopping(String barcodeContents) {
        URL u;
        InputStream is = null;
        DataInputStream dis = null;
        String s;
        StringBuilder sb = new StringBuilder();
        String jsonString = null;
        try {
            u = new URL("https://www.googleapis.com/shopping/search/v1/public/products?key=" + SHOPPING_API_KEY
                    + "&country=US&restrictBy=gtin:" + barcodeContents + "&startIndex=1&maxResults=1");
            is = u.openStream();
            dis = new DataInputStream(new BufferedInputStream(is));
            while ((s = dis.readLine()) != null) {
                sb = sb.append(s + "\n");
            }
        } catch (MalformedURLException mue) {
            mue.printStackTrace();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException ioe) {
                    ioe.printStackTrace();
                }
            }
        }

        jsonString = sb.toString();
        return jsonString;
    }

    /**
     * This method receives a JSON String and gets any information we want from
     * it (e.g. Title, price, description, image of the product etc). Currently
     * we are only getting the title of the product.
     * 
     * @param barcodeContents
     *            The unique Global Trade Item Number of the product.
     * @return The title of the product we are searching for.
     */
    public String getGoogleShoppingInfo(String barcodeContents) {

        String jsonString = getJsonStringFromGoogleShopping(barcodeContents);
        String productTitle = null;

        if (jsonString != null) {
            try {
                JSONObject jsonObject = new JSONObject(jsonString);

                JSONArray itemsArray = jsonObject.getJSONArray("items");
                JSONObject itemObject = itemsArray.getJSONObject(0);
                JSONObject productObject = itemObject.getJSONObject("product");
                productTitle = productObject.getString("title");
                return productTitle;

            } catch (JSONException je) {
                je.printStackTrace();
            }
        }
        return null;
    }

}