InventoryIncrementItemServlet.java Source code

Introduction

Here is the source code for InventoryIncrementItemServlet.java

Source

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

import protocol.HttpRequest;
import protocol.HttpResponse;
import protocol.HttpResponseFactory;
import protocol.IServlet;
import protocol.Protocol;

/*
 * InventoryAddNewItemServlet.java
 * Nov 11, 2015
 *
 * Simple Web Server (SWS) for EE407/507 and CS455/555
 * 
 * Copyright (C) 2011 Chandan Raj Rupakheti, Clarkson University
 * 
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License 
 * as published by the Free Software Foundation, either 
 * version 3 of the License, or 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 Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/lgpl.html>.
 * 
 * Contact Us:
 * Chandan Raj Rupakheti (rupakhcr@clarkson.edu)
 * Department of Electrical and Computer Engineering
 * Clarkson University
 * Potsdam
 * NY 13699-5722
 * http://clarkson.edu/~rupakhcr
 */

/**
 * 
 * @author Chandan R. Rupakheti (rupakhcr@clarkson.edu)
 */
public class InventoryIncrementItemServlet implements IServlet {

    /* (non-Javadoc)
     * @see protocol.IServlet#doWork(protocol.HttpRequest, java.lang.String)
     */
    @Override
    public HttpResponse doWork(HttpRequest request, String rootDirectory) {
        HttpResponse response;
        try {
            String inventoryUrl = "./web/inventory.json";
            File inventory = new File(inventoryUrl);

            StringBuilder sb = new StringBuilder();
            Scanner sc = new Scanner(inventory);
            while (sc.hasNext()) {
                sb.append(sc.nextLine());
            }
            sc.close();

            // Add this new book to the list of existing books
            Gson gson = new Gson();
            InventoryObject[] inventoryArray = gson.fromJson(sb.toString(), InventoryObject[].class);
            ArrayList<InventoryObject> inventoryList = new ArrayList<InventoryObject>(
                    Arrays.asList(inventoryArray));

            String body = new String(request.getBody());
            System.out.println(body);
            String[] newItem = body.split("&");

            // Find existing item and add passed quantity
            int id = Integer.parseInt(newItem[0].split("=")[1]);
            int quant = Integer.parseInt(newItem[1].split("=")[1]);
            for (InventoryObject item : inventoryList) {
                if (item.getID() == id) {
                    if (item.getQuantity() == 0 && quant == -1) {
                        return HttpResponseFactory.create400BadRequest(Protocol.CLOSE);
                    } else {
                        item.setQuantity(item.getQuantity() + quant);
                    }
                }
            }

            // Serialize new list
            Gson gsonBuilder = new GsonBuilder().setPrettyPrinting().create();
            String arrayListToJson = gsonBuilder.toJson(inventoryList);

            BufferedWriter bw = new BufferedWriter(new FileWriter(inventory));
            bw.write(arrayListToJson);
            bw.close();

            response = HttpResponseFactory.create200OK(inventory, Protocol.CLOSE);
        } catch (Exception e) {
            response = HttpResponseFactory.create404NotFound(Protocol.CLOSE);
        }
        return response;
    }

}