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-rw-r--r--Week9/src/com/camilstaps/shop/Database.java390
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+/**
+ * Copyright (c) 2015 Camil Staps <info@camilstaps.nl>
+ * See the LICENSE file for copying permission.
+ */
+
+package com.camilstaps.shop;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.regex.Pattern;
+
+/**
+ * The Shop database
+ * @author Camil Staps, s4498062
+ */
+public class Database {
+
+ /**
+ * This is a singleton
+ */
+ private static Database instance;
+
+ /**
+ * Keep the database in working memory during runtime
+ */
+ private Set<User> users;
+ private Set<Article> articles;
+ private Set<Category> categories;
+ private Set<Order> orders;
+
+ /**
+ * Files to store the database
+ */
+ private final File FILE_DB = new File("./db");
+ private final File FILE_USERS = new File("./db/users.db");
+ private final File FILE_ARTICLES = new File("./db/articles.db");
+ private final File FILE_CATEGORIES = new File("./db/categories.db");
+ private final File FILE_ORDERS = new File("./db/orders.db");
+
+ /**
+ * Don't use this constructor. This is a singleton: use getInstance() instead.
+ * @see self#getInstance()
+ */
+ public Database() {
+ if (!FILE_DB.exists())
+ FILE_DB.mkdir();
+
+ readUsers();
+ readArticles();
+ readCategories();
+ readOrders();
+ }
+
+ /**
+ * Get an instance of the database. This is a singleton.
+ * @return the database
+ */
+ public static Database getInstance() {
+ if (instance == null) {
+ instance = new Database();
+ }
+ return instance;
+ }
+
+ /**
+ * Add an item to the database
+ * @param item the item
+ * @throws com.camilstaps.shop.DuplicateEntryException
+ * @throws ClassCastException if the item to remove is not a DatabaseItem
+ */
+ public void addItem(DatabaseItem item) throws DuplicateEntryException {
+ if (item instanceof User) {
+ if (isUserExists(((User) item).getNr())) {
+ throw new DuplicateEntryException();
+ }
+ users.add((User) item);
+ } else if (item instanceof Article) {
+ if (isArticleExists(((Article) item).getName())) {
+ throw new DuplicateEntryException();
+ }
+ articles.add((Article) item);
+ } else if (item instanceof Category) {
+ if (isCategoryExists(((Category) item).getName())) {
+ throw new DuplicateEntryException();
+ }
+ categories.add((Category) item);
+ } else if (item instanceof Order) {
+ orders.add((Order) item);
+ } else {
+ throw new ClassCastException();
+ }
+ }
+
+ /**
+ * Remove an item from the database
+ * @param item the item to remove
+ * @throws ClassCastException if the item to remove is not a DatabaseItem
+ */
+ public void removeItem(DatabaseItem item) {
+ if (item instanceof User) {
+ users.remove((User) item);
+ } else if (item instanceof Article) {
+ articles.remove((Article) item);
+ } else if (item instanceof Category) {
+ categories.remove((Category) item);
+ } else if (item instanceof Order) {
+ orders.remove((Order) item);
+ } else {
+ throw new ClassCastException();
+ }
+ }
+
+ /**
+ * Save the database to the filesystem.
+ * @return true on success, false on failure
+ */
+ public boolean write() {
+ return writeUsers() && writeArticles() && writeCategories() && writeOrders();
+ }
+
+ /**
+ * Check if there exists a user with a certain U/S-number
+ * @param nr
+ * @return
+ */
+ public boolean isUserExists(String nr) {
+ for (User user : users) {
+ if (user.getNr().equals(nr)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Check if an article with a name exists
+ * @param name
+ * @return
+ */
+ public boolean isArticleExists(String name) {
+ for (Article article : articles) {
+ if (article.getName().equals(name)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Check if a category with a name exists
+ * @param name
+ * @return
+ */
+ public boolean isCategoryExists(String name) {
+ for (Category category : categories) {
+ if (category.getName().equals(name)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Get the set of users
+ * @return
+ */
+ public Set<User> getUsers() {
+ return users;
+ }
+
+ /**
+ * Get the set of articles
+ * @return
+ */
+ public Set<Article> getArticles() {
+ return articles;
+ }
+
+ /**
+ * Get the set of categories
+ * @return
+ */
+ public Set<Category> getCategories() {
+ return categories;
+ }
+
+ /**
+ * Get an array of the names of the categories
+ * @return
+ */
+ public String[] getCategoryNames() {
+ String[] categoryNames = new String[categories.size()];
+ int i = 0;
+ for (Category c : categories) {
+ categoryNames[i++] = c.getName();
+ }
+ return categoryNames;
+ }
+
+ /**
+ * Get the set of orders
+ * @return
+ */
+ public Set<Order> getOrders() {
+ return orders;
+ }
+
+ /**
+ * Get the set of articles of which the name or description matches a regular expression
+ * @param p the regular expression
+ * @return
+ */
+ public Set<Article> searchArticle(Pattern p) {
+ Set<Article> result = new HashSet<>();
+ for (Article a : articles) {
+ if (p.matcher(a.getName()).find() || p.matcher(a.getDescription()).find()) {
+ result.add(a);
+ }
+ }
+ return result;
+ }
+
+ /**
+ * Get a user by his number
+ * @param number
+ * @return
+ * @throws com.camilstaps.shop.ItemNotFoundException
+ */
+ public User getUser(String number) throws ItemNotFoundException {
+ for (User u : users) {
+ if (u.getNr().equals(number)) {
+ return u;
+ }
+ }
+ throw new ItemNotFoundException();
+ }
+
+ /**
+ * Get an article by its name
+ * @param name
+ * @return
+ * @throws ItemNotFoundException
+ */
+ public Article getArticle(String name) throws ItemNotFoundException {
+ for (Article a : articles) {
+ if (a.getName().equals(name)) {
+ return a;
+ }
+ }
+ throw new ItemNotFoundException();
+ }
+
+ /**
+ * Get a category by a name
+ * @param name
+ * @return
+ */
+ public Category getCategory(String name) throws ItemNotFoundException {
+ for (Category c : categories) {
+ if (c.getName().equals(name)) {
+ return c;
+ }
+ }
+ throw new ItemNotFoundException();
+ }
+
+ /**
+ * Read the users from the database into RAM
+ */
+ private void readUsers() {
+ users = new HashSet<>();
+ try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(FILE_USERS))) {
+ users = (Set) in.readObject();
+ in.close();
+ } catch (FileNotFoundException ex) {
+ } catch (IOException | ClassNotFoundException ex) {
+ }
+ }
+
+ /**
+ * Read the articles from the database into RAM
+ */
+ private void readArticles() {
+ articles = new HashSet<>();
+ try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(FILE_ARTICLES))) {
+ articles = (Set) in.readObject();
+ in.close();
+ } catch (FileNotFoundException ex) {
+ } catch (IOException | ClassNotFoundException ex) {
+ }
+ }
+
+ /**
+ * Read the categories from the database into RAM
+ */
+ private void readCategories() {
+ categories = new HashSet<>();
+ try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(FILE_CATEGORIES))) {
+ categories = (Set) in.readObject();
+ in.close();
+ } catch (FileNotFoundException ex) {
+ } catch (IOException | ClassNotFoundException ex) {
+ }
+ }
+
+ /**
+ * Read the orders from the database into RAM
+ */
+ private void readOrders() {
+ orders = new HashSet<>();
+ try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(FILE_ORDERS))) {
+ orders = (Set) in.readObject();
+ in.close();
+ } catch (FileNotFoundException ex) {
+ } catch (IOException | ClassNotFoundException ex) {
+ }
+ }
+
+ /**
+ * Write the users from RAM to the database
+ */
+ private boolean writeUsers() {
+ System.err.println("Saving users...");
+
+ try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(FILE_USERS))) {
+ out.writeObject(users);
+ out.close();
+ return true;
+ } catch (IOException ex) {
+ ex.printStackTrace();
+ }
+ return false;
+ }
+
+ /**
+ * Write the articles from RAM to the database
+ */
+ private boolean writeArticles() {
+ System.err.println("Saving articles...");
+
+ try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(FILE_ARTICLES))) {
+ out.writeObject(articles);
+ out.close();
+ return true;
+ } catch (IOException ex) {
+ ex.printStackTrace();
+ }
+ return false;
+ }
+
+ /**
+ * Write the categories from RAM to the database
+ */
+ private boolean writeCategories() {
+ System.err.println("Saving categories...");
+
+ try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(FILE_CATEGORIES))) {
+ out.writeObject(categories);
+ out.close();
+ return true;
+ } catch (IOException ex) {
+ ex.printStackTrace();
+ }
+ return false;
+ }
+
+ /**
+ * Write the orders from RAM to the database
+ */
+ private boolean writeOrders() {
+ System.err.println("Saving orders...");
+
+ try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(FILE_ORDERS))) {
+ out.writeObject(orders);
+ out.close();
+ return true;
+ } catch (IOException ex) {
+ ex.printStackTrace();
+ }
+ return false;
+ }
+
+} \ No newline at end of file
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-02 13:03:49 +0000