Hackerrank api problem solved

Run PMD: ./run.sh pmd -d /home/anit/work/codechallenge-java-pom/src/main/java/hackerrank/api -f text -R /home/anit/work/codechallenge-java-pom/.pmd --cache /tmp/codechallenge-pmd-analysis | more
Run unit test: mvn test -Dtest=hackerranktest.api.BarcodeReaderTest

Author: anitsh

src/main/java/hackerrank/api/BarcodeReader.java

@@ -1,64 +1,84 @@
 package hackerrank.api;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.DeserializationFeature;
-import com.fasterxml.jackson.databind.ObjectMapper;
-
 import java.io.IOException;
 import java.net.MalformedURLException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
+/**
+ * Get inventories from barcode
+ *
+ */
 public class BarcodeReader   {
+    /**
+     * Class name
+     */
+    private final static String TAG = "BarcodeReader";
 
-    private final static String TAG = BarcodeReader.class.getSimpleName();
-    private final static Logger logger =
+    /**
+     * Log messages
+     */
+    private final static Logger LOGGER =
             Logger.getLogger(Logger.GLOBAL_LOGGER_NAME);
-    private final static String inventoryURI = "https://jsonmock.hackerrank.com/api/inventory";
 
-    public Inventory read(int barcode) {
-        Inventory inventory = null;
-        String barcodeURI = inventoryURI + "?barcode=";
+    /**
+     * Inventory URI
+     */
+    private final static String INVENTORY_URI = "https://jsonmock.hackerrank.com/api/inventory";
+
+    /**
+     * Barcode
+     */
+    private final int barcode;
+
+    /**
+     *
+     * @return int barcode
+     */
+    public int getBarcode() {
+        return barcode;
+    }
+
+    /**
+     *
+     */
+    public BarcodeReader(final int barcode) {
+        this.barcode = barcode;
+    }
+
+    /**
+     * Read inventory from barcode.
+     *
+     * @return Inventory
+     */
+    public Inventory read() {
+        Inventory inventory = new Inventory();
+        final String barcodeURI = INVENTORY_URI + "?barcode=";
 
         try {
-            String inventoryJSONString = InputStreamConverter.toString(
-                    HttpRequests.get(barcodeURI+barcode));
+            final String inventoryJSON = InputStreamConverterUtil.toString(
+                    HttpRequestsUtil.get(barcodeURI + barcode));
 
-            inventory =  getInventories(inventoryJSONString)[0];
+            inventory =  inventory.getInventories(inventoryJSON)[0];
 
         } catch (InventoryNotFoundException e) {
-            if (logger.isLoggable(Level.INFO)) {
-                logger.log(Level.INFO, TAG + " InventoryNotFoundException: " + e.getMessage());
+            if (LOGGER.isLoggable(Level.INFO)) {
+                LOGGER.log(Level.INFO, TAG + " InventoryNotFoundException: " + e.getMessage());
             }
         } catch (MalformedURLException e) {
-            if (logger.isLoggable(Level.SEVERE)) {
-                logger.log(Level.SEVERE, TAG + " MalformedURLException: " + e.getMessage());
+            if (LOGGER.isLoggable(Level.SEVERE)) {
+                LOGGER.log(Level.SEVERE, TAG + " MalformedURLException: " + e.getMessage());
             }
         } catch (IOException e) {
-            if (logger.isLoggable(Level.SEVERE)) {
-                logger.severe(TAG + " IOException: " + e.getMessage());
-            }
-        } catch (Exception e) {
-            if (logger.isLoggable(Level.INFO)) {
-                logger.info(TAG + " Exception: " + e.getMessage());
+            if (LOGGER.isLoggable(Level.SEVERE)) {
+                LOGGER.severe(TAG + " IOException: " + e.getMessage());
             }
         }
 
         return inventory;
     }
 
-    private Inventory[] getInventories(String jsonInventories)
-            throws JsonProcessingException {
 
-        ObjectMapper objectMapper = new ObjectMapper();
-        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
-        objectMapper.configure(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES, false);
-        objectMapper.configure(DeserializationFeature.USE_JAVA_ARRAY_FOR_JSON_ARRAY, true);
-
-        return objectMapper
-                .readValue(jsonInventories,
-                        Inventory[].class);
-    }
 
 }
 

src/main/java/hackerrank/api/HttpRequests.java

@@ -0,0 +1,37 @@
+package hackerrank.api;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+/**
+ * Process HTTP Requests
+ *
+ */
+@SuppressWarnings("PMD.LawOfDemeter")
+public final class HttpRequestsUtil {
+
+    /**
+     * To prevent initialization
+     */
+    private HttpRequestsUtil() {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     * Process HTTP GET request
+     *
+     * @param url String
+     * @return InputStream
+     * @throws IOException``
+     */
+    public static InputStream get(final String url)
+            throws IOException {
+        final URL urlObject = new URL(url);
+        final HttpURLConnection conn = (HttpURLConnection) urlObject.openConnection();
+        conn.setRequestMethod("GET");
+
+        return conn.getInputStream();
+    }
+}

src/main/java/hackerrank/api/HttpRequestsUtil.java

@@ -0,0 +1,54 @@
+package hackerrank.api;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+/**
+ * Convert Input Stream to String
+ */
+@SuppressWarnings("PMD.LawOfDemeter")
+public final class InputStreamConverterUtil {
+
+    /**
+     * To prevent initialization
+     */
+    private InputStreamConverterUtil() {
+        throw new UnsupportedOperationException();
+    }
+
+    /**
+     *
+     * @param inputStream InputStream
+     * @return String JSON inventory string
+     * @throws InventoryNotFoundException Inventory Not Found
+     */
+    public static String toString(final InputStream inputStream)
+            throws InventoryNotFoundException, IOException {
+
+        final StringBuilder stringBuilder = new StringBuilder();
+        String line;
+
+        final BufferedReader reader = new BufferedReader(
+                new InputStreamReader(inputStream));
+        do {
+            line = reader.readLine();
+            stringBuilder.append(line).append('\n');
+        } while (line != null);
+
+        final JSONObject json = new JSONObject(
+                stringBuilder.toString());
+        final  JSONArray dataArray = (JSONArray) json.get("data");
+
+        if ( dataArray.isEmpty() ) {
+            throw new InventoryNotFoundException(
+                    "Inventory Not Found!");
+        }
+
+        return dataArray.toString();
+    }
+}