ca.mcgill.cs.creco.data.CRData.java Source code

Introduction

Here is the source code for ca.mcgill.cs.creco.data.CRData.java

Source

/**
 * Copyright 2014 McGill University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package ca.mcgill.cs.creco.data;

import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;

import org.springframework.stereotype.Component;

import ca.mcgill.cs.creco.data.json.JsonLoadingService;

/**
 * Root of the object graph representing the consumer reports database. 
 * All of the data is accessible through a singleton CRData object. Just 
 * create a new CRData object to get started. Normally in production this
 * will be built when the server starts up.
 */
@Component
public final class CRData implements IDataStore {
    private static final String DEFAULT_CATEGORY_FILENAME = "category.json";
    private static final String DEFAULT_DEAD_LINKS_FILENAME = "dead_links.json";

    private static final String[] DEFAULT_PRODUCT_FILENAMES = { "appliances.json", "electronicsComputers.json",
            "cars.json", "health.json", "homeGarden.json", "food.json", "babiesKids.json", "money.json" };

    private HashMap<String, Product> aProducts = new HashMap<String, Product>();
    private HashMap<String, Category> aCategoryIndex = new HashMap<String, Category>();

    private CRData() throws IOException {
        this(DEFAULT_PRODUCT_FILENAMES, DEFAULT_CATEGORY_FILENAME, DEFAULT_DEAD_LINKS_FILENAME);
    }

    private CRData(String[] pProductFileNames, String pCategoryFileName) throws IOException {
        this(pProductFileNames, pCategoryFileName, DEFAULT_DEAD_LINKS_FILENAME);
    }

    private CRData(String[] pProductFileNames, String pCategoryFileName, String pDeadlinksFilename)
            throws IOException {

        IDataLoadingService loadingService = new JsonLoadingService(DataPath.get(), pCategoryFileName,
                pProductFileNames, pDeadlinksFilename);
        CategoryTree lCatTree = new CategoryTree();

        loadingService.loadCategories(lCatTree);

        // Build the categoryTree index
        lCatTree.indexRootCategories();
        lCatTree.eliminateAllSingletons();

        loadingService.loadProducts(lCatTree);

        // Put links from products to categories and vice-versa
        lCatTree.associateProducts();

        // Roll up useful pre-processed statistics and find equivalence classes
        lCatTree.refresh();
        lCatTree.findEquivalenceClasses();

        // Copy the Products and Categories to CRData
        for (Product prod : lCatTree.getProducts()) {
            aProducts.put(prod.getId(), prod);
        }
        for (CategoryNode catNode : lCatTree.getCategories()) {
            Category newCategory = new Category(catNode.getId(), catNode.getName(), catNode.getRootCategoryName(),
                    catNode.getProducts());
            aCategoryIndex.put(newCategory.getId(), newCategory);

            // Associate products to the equivalence class that contains them
            for (Product prod : newCategory.getProducts()) {
                prod.setCategory(newCategory);
            }
        }

    }

    /**
     * @param pIndex The requested index.
     * @return The category corresponding to pIndex.
     */
    public Category getCategory(String pIndex) {
        return aCategoryIndex.get(pIndex);
    }

    @Override
    public Product getProduct(String pId) {
        return aProducts.get(pId);
    }

    @Override
    public Collection<Category> getCategories() {
        return Collections.unmodifiableCollection(aCategoryIndex.values());
    }

    /**
     * @return An iterator on the product list.
     */
    @Override
    public Collection<Product> getProducts() {
        return Collections.unmodifiableCollection(aProducts.values());
    }

}