feature: Added Domain Model pattern (#1795)

* domain-model pattern * fixed optional get before check isPresent * readme minor changes * change currency representation with joda money * changed names of test methods * fixed code smells * Update domain-model/README.md Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com> * Update domain-model/README.md Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com> * updated readme and diagrams Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>
2026-05-16 18:59:21 +00:00 · 2021-07-22 16:58:21 +03:00
parent eaeb6e717c
commit eac85678f0
20 changed files with 1765 additions and 8 deletions
@@ -0,0 +1,153 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.domainmodel;
+
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+import lombok.Builder;
+import lombok.Getter;
+import lombok.NonNull;
+import lombok.Setter;
+import lombok.extern.slf4j.Slf4j;
+import org.joda.money.Money;
+
+/**
+ * This class organizes domain logic of customer.
+ * A single instance of this class
+ * contains both the data and behavior of a single customer.
+ */
+@Slf4j
+@Getter
+@Setter
+@Builder
+public class Customer {
+
+  @NonNull private final CustomerDao customerDao;
+  @Builder.Default private List<Product> purchases = new ArrayList<>();
+  @NonNull private String name;
+  @NonNull private Money money;
+
+  /**
+   * Save customer or update if customer already exist.
+   */
+  public void save() {
+    try {
+      Optional<Customer> customer = customerDao.findByName(name);
+      if (customer.isPresent()) {
+        customerDao.update(this);
+      } else {
+        customerDao.save(this);
+      }
+    } catch (SQLException ex) {
+      LOGGER.error(ex.getMessage());
+    }
+  }
+
+  /**
+   * Add product to purchases, save to db and withdraw money.
+   *
+   * @param product to buy.
+   */
+  public void buyProduct(Product product) {
+    LOGGER.info(
+        String.format(
+            "%s want to buy %s($%.2f)...",
+            name, product.getName(), product.getSalePrice().getAmount()));
+    try {
+      withdraw(product.getSalePrice());
+    } catch (IllegalArgumentException ex) {
+      LOGGER.error(ex.getMessage());
+      return;
+    }
+    try {
+      customerDao.addProduct(product, this);
+      purchases.add(product);
+      LOGGER.info(String.format("%s bought %s!", name, product.getName()));
+    } catch (SQLException exception) {
+      receiveMoney(product.getSalePrice());
+      LOGGER.error(exception.getMessage());
+    }
+  }
+
+  /**
+   * Remove product from purchases, delete from db and return money.
+   *
+   * @param product to return.
+   */
+  public void returnProduct(Product product) {
+    LOGGER.info(
+        String.format(
+            "%s want to return %s($%.2f)...",
+            name, product.getName(), product.getSalePrice().getAmount()));
+    if (purchases.contains(product)) {
+      try {
+        customerDao.deleteProduct(product, this);
+        purchases.remove(product);
+        receiveMoney(product.getSalePrice());
+        LOGGER.info(String.format("%s returned %s!", name, product.getName()));
+      } catch (SQLException ex) {
+        LOGGER.error(ex.getMessage());
+      }
+    } else {
+      LOGGER.error(String.format("%s didn't buy %s...", name, product.getName()));
+    }
+  }
+
+  /**
+   * Print customer's purchases.
+   */
+  public void showPurchases() {
+    Optional<String> purchasesToShow =
+        purchases.stream()
+            .map(p -> p.getName() + " - $" + p.getSalePrice().getAmount())
+            .reduce((p1, p2) -> p1 + ", " + p2);
+
+    if (purchasesToShow.isPresent()) {
+      LOGGER.info(name + " bought: " + purchasesToShow.get());
+    } else {
+      LOGGER.info(name + " didn't bought anything");
+    }
+  }
+
+  /**
+   * Print customer's money balance.
+   */
+  public void showBalance() {
+    LOGGER.info(name + " balance: " + money);
+  }
+
+  private void withdraw(Money amount) throws IllegalArgumentException {
+    if (money.compareTo(amount) < 0) {
+      throw new IllegalArgumentException("Not enough money!");
+    }
+    money = money.minus(amount);
+  }
+
+  private void receiveMoney(Money amount) {
+    money = money.plus(amount);
+  }
+}