Java tutorial
/************************************************************************************** SaveDollars An open source Android application that helps users to compare prices of a product across different ecommerce sites and make a decision about purchase. Copyright (C) 2013 Smita Kundargi and Jeanne Betcy Victor 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/. Following is the link for the repository: https://github.com/SmitaBetcy/SaveDollars Please, see the file license in this distribution for license terms. Link is https://github.com/SmitaBetcy/SaveDollars/blob/master/License References: https://developers.google.com/shopping-search/v1/reference-response-format https://developers.google.com/shopping-search/v1/getting_started https://code.google.com/p/zxing/wiki/ScanningViaIntent http://stackoverflow.com/questions/8632529/listview-with-multiple-strings http://sweetclipart.com/ Author - Smita Kundargi and Jeanne Betcy Victor email: ksmita@pdx.edu and jbv3@pdx.edu ******************************************************************************************/ package com.savedollars; import java.io.BufferedInputStream; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import android.app.ListActivity; import android.content.Intent; import android.net.Uri; import android.os.Bundle; import android.os.StrictMode; import android.util.Log; import android.view.Menu; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; import android.widget.TextView; import com.adapter.ListViewAdapter; import com.example.savedollars.R; /******************************************************************************************************* ** ProductTotalPriceDisplay is used to invoke the google shopping API and parse * the JSON Data to sort and display the (price+Shipping price) of the product * in ascending order(lower to higher price) for different merchants and it * allows the user to visit the home page of the merchant by one click. *********************************************************************************************************/ public class ProductTotalPriceDisplay extends ListActivity { private List<Float> sortedList = new ArrayList<Float>(); private Map merchantMap = new HashMap(); private Map<Object, Object> sortedMap = new LinkedHashMap<Object, Object>(); private String JSONData = ""; private int totalCount = 0; private String[][] PDT_INFO; public Set<Object> merchantNameKeys; public static String[] merchantNames; public String pdtName; public String merchantPage; private Map merchantLinkMap = new HashMap(); private static final String LOG_TAG = "ProductTotalPriceDisplay"; @Override protected void onCreate(Bundle savedInstanceState) { StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites() .detectNetwork().penaltyLog().build()); String barcodeNumber = (getIntent().getStringExtra("barcodeNumber")); /* * If barcode number is scanned from main screen, Google API server call * is made to retrieve the product information. If we are returning from * existing view ( shipping, stocks) no server call is made. We display * the product information already stored in JSONData */ if (barcodeNumber != null) { getProductDetails(barcodeNumber); } else { JSONData = (getIntent().getStringExtra("JsonData")); parseJsonData(JSONData); } super.onCreate(savedInstanceState); if (totalCount == 0) { setContentView(R.layout.nopdtinfo); } else { setContentView(R.layout.pdttotalpriceview); // Setting Product Name TextView productName = (TextView) findViewById(R.id.pdtNameTextView); productName.setText(pdtName); Iterator objMapIterator = sortedMap.entrySet().iterator(); int rowIndex = 0; PDT_INFO = new String[totalCount][2]; while (objMapIterator.hasNext()) { Map.Entry keyValuePairs = (Map.Entry) objMapIterator.next(); PDT_INFO[rowIndex][0] = String.valueOf(keyValuePairs.getKey()); PDT_INFO[rowIndex][1] = "$" + String.valueOf(keyValuePairs.getValue()); rowIndex++; } ListViewAdapter listv = new ListViewAdapter(this, PDT_INFO); setListAdapter(listv); final ListView lv = getListView(); lv.setTextFilterEnabled(true); lv.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> parent, View view, int position, long id) { lv.getItemAtPosition(position); String pdtKey = PDT_INFO[position][0]; String merchantLink = (String) merchantLinkMap.get(pdtKey); Uri uri = Uri.parse(merchantLink); Intent intent = new Intent(Intent.ACTION_VIEW, uri); startActivity(intent); } }); } } private void getProductDetails(String barcodeNumber) { String baseURL = getString(R.string.searchURL); String key = getString(R.string.key); String country = getString(R.string.country); String urlString = baseURL + "&" + key + "&" + country + "&" + "q=" + barcodeNumber; try { URL url = new URL(urlString); HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection(); InputStream in = new BufferedInputStream(urlConnection.getInputStream()); BufferedReader reader = new BufferedReader(new InputStreamReader(in)); StringBuilder out = new StringBuilder(); String line; String data; while ((line = reader.readLine()) != null) { out.append(line); } // JSON data stored as string. data = out.toString(); parseJsonData(data); } catch (MalformedURLException e) { Log.e(LOG_TAG, "Error processing Google Shopping API URL", e); } catch (IOException e) { Log.e(LOG_TAG, "Error connecting to Google Shopping API", e); } } private void parseJsonData(String data) { // Convert to JSON object for parsing JSONData = data; try { JSONObject jsonResponse = new JSONObject(data); if (jsonResponse.has("items")) { JSONArray parsedItems = jsonResponse.getJSONArray("items"); JSONObject inventory = null; for (int j = 0; j < parsedItems.length(); j++) { inventory = parsedItems.getJSONObject(j); JSONObject objPrice = inventory.getJSONObject("product"); JSONObject merchant = objPrice.getJSONObject("author"); String merchantName = merchant.getString("name"); JSONArray invObj = objPrice.getJSONArray("inventories"); for (int z = 0; z < invObj.length(); z++) { JSONObject price = invObj.getJSONObject(z); String productPrice = price.getString("price"); String shipping = "0.0"; if (price.has("shipping")) { shipping = price.getString("shipping"); } float finalPrice = Float.parseFloat(productPrice) + Float.parseFloat(shipping); merchantMap.put(merchantName, finalPrice); sortedList.add(Float.valueOf(finalPrice)); } JSONArray imgObj = objPrice.getJSONArray("images"); for (int i = 0; i < imgObj.length(); i++) { JSONObject imgLink = imgObj.getJSONObject(i); String img = imgLink.getString("link"); } // retrieve product title pdtName = objPrice.getString("title"); // retrieve merchant page merchantPage = objPrice.getString("link"); merchantLinkMap.put(merchantName, merchantPage); } Collections.sort(sortedList); sortMerchantPrices(); merchantNameKeys = sortedMap.keySet(); merchantNames = Arrays.copyOf(merchantNameKeys.toArray(), merchantNameKeys.toArray().length, String[].class); } } catch (JSONException e) { Log.e(LOG_TAG, "Cannot process JSON results", e); } } /* * method : sortMerchantPrices arguments : none description: Sorts a hashmap * containing merchant names and prices by values ( prices ). The idea is to * convert map to list and then sort before converting back to map again. * returns : void */ private void sortMerchantPrices() { List objList = new LinkedList(merchantMap.entrySet()); Collections.sort(objList, new Comparator() { public int compare(Object o1, Object o2) { return ((Comparable) ((Map.Entry) (o1)).getValue()).compareTo(((Map.Entry) (o2)).getValue()); } }); for (Iterator it = objList.iterator(); it.hasNext();) { Map.Entry entry = (Map.Entry) it.next(); sortedMap.put(entry.getKey(), entry.getValue()); totalCount++; } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, menu); return true; } /* Invoking appropriate activity when each button(Total,Price,Stock,ShippingCost) is clicked */ public void pdttotalpriceview(View v) { Intent searchIntent = new Intent(ProductTotalPriceDisplay.this, ProductTotalPriceDisplay.class); searchIntent.putExtra("JsonData", JSONData); startActivity(searchIntent); } public void pdtpriceview(View v) { Intent searchIntent = new Intent(ProductTotalPriceDisplay.this, ProductPriceDisplay.class); searchIntent.putExtra("JsonData", JSONData); startActivity(searchIntent); } public void pdtshippingpriceview(View v) { Intent searchIntent = new Intent(ProductTotalPriceDisplay.this, ProductShippingPriceDisplay.class); searchIntent.putExtra("JsonData", JSONData); startActivity(searchIntent); } public void pdtstockview(View v) { Intent searchIntent = new Intent(ProductTotalPriceDisplay.this, ProductStockDisplay.class); searchIntent.putExtra("JsonData", JSONData); startActivity(searchIntent); } public void activity_main(View v) { Intent searchIntent = new Intent(ProductTotalPriceDisplay.this, MainActivity.class); startActivity(searchIntent); } }