fixed checkstyle for App Class, created package-info

active-record/src/main/java/com/iluwatar/activerecord/App.java

@@ -1,11 +1,64 @@
-package com.iluwatar.activerecord;
+/*
+ * This project is licensed under the MIT license.
+ * Module model-view-viewmodel is using ZK framework
+ * licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 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.activerecord;
+import lombok.extern.slf4j.Slf4j;
 import java.sql.SQLException;
 import java.util.List;
 
-public class App {
+/**
+ * The Active Record pattern is an architectural pattern that simplifies
+ * database interactions by encapsulating database access logic within
+ * the domain model. This pattern allows objects to be responsible for
+ * their own persistence, providing methods for CRUD operations directly
+ * within the model class.
+ *
+ * <p>In this example, we demonstrate the Active Record pattern
+ * by creating, updating, retrieving, and deleting user records in
+ * a SQLite database. The User class contains methods to perform
+ * these operations, ensuring that the database interactions are
+ * straightforward and intuitive.
+ */
+
+@Slf4j
+public final class App {
+
+  private App() {
+    throw new UnsupportedOperationException("Utility class");
+  }
+
+  /**
+   * Entry Point.
+   *
+   * @param args the command line arguments - not used
+   */
 
-  public static void main(String[] args) {
+
+  public static void main(final String[] args) {
     try {
       // Initialize the database and create the users table if it doesn't exist
       User.initializeTable();
@@ -14,12 +67,14 @@ public static void main(String[] args) {
       // Create a new user and save it to the database
       User user1 = new User(null, "John Doe", "[email protected]");
       user1.save();
-      System.out.println("New user saved: " + user1.getName() + " with ID " + user1.getId());
+      System.out.println("New user saved: " + user1.getName()
+          + " with ID " + user1.getId());
 
       // Retrieve and display the user by ID
       User foundUser = User.findById(user1.getId());
       if (foundUser != null) {
-        System.out.println("User found: " + foundUser.getName() + " with email " + foundUser.getEmail());
+        System.out.println("User found: " + foundUser.getName()
+            + " with email " + foundUser.getEmail());
       } else {
         System.out.println("User not found.");
       }
@@ -29,22 +84,24 @@ public static void main(String[] args) {
       foundUser.setName("John Updated");
       foundUser.setEmail("[email protected]");
       foundUser.save();
-      System.out.println("User updated: " + foundUser.getName() + " with email " + foundUser.getEmail());
+      System.out.println("User updated: " + foundUser.getName()
+          + " with email " + foundUser.getEmail());
 
       // Retrieve all users
       List<User> users = User.findAll();
       System.out.println("All users in the database:");
       for (User user : users) {
-        System.out.println("ID: " + user.getId() + ", Name: " + user.getName() + ", Email: " + user.getEmail());
+        System.out.println("ID: " + user.getId()
+            + ", Name: " + user.getName()
+            + ", Email: " + user.getEmail());
       }
 
       // Delete the user
       try {
         System.out.println("Deleting user with ID: " + foundUser.getId());
         foundUser.delete();
         System.out.println("User successfully deleted!");
-      }
-      catch (Exception e){
+      } catch (Exception e) {
         System.out.println(e.getMessage());
       }
 

active-record/src/main/java/com/iluwatar/activerecord/User.java

@@ -1,7 +1,11 @@
 package com.iluwatar.activerecord;
 
-import lombok.Data;
-import java.sql.*;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.ArrayList;
 import java.util.List;
 

active-record/src/main/java/com/iluwatar/activerecord/package-info.java

@@ -0,0 +1,60 @@
+/*
+ * This project is licensed under the MIT license.
+ * Module model-view-viewmodel is using
+ * ZK framework licensed under LGPL (see lgpl-3.0.txt).
+ *
+ * The MIT License
+ * Copyright © 2014-2022 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.
+ */
+
+/**
+ * Context and problem
+ * Most applications require a way to interact with a database to perform
+ * CRUD (Create, Read, Update, Delete) operations.
+ * Traditionally, this involves writing a lot of boilerplate code
+ * for database access, which can be error-prone and hard to maintain.
+ * This is especially true in applications with
+ * complex data models and relationships.
+ *
+ * <p>Often, developers need to write separate classes for database access and
+ * domain models, leading to a separation of concerns
+ * that can make the codebase more complex and harder to understand.
+ * Additionally, changes to the database schema can require significant
+ * changes to the data access code, increasing the maintenance burden.
+ *
+ * <p>Maintaining this separation can force the application to
+ * adhere to at least some of the database's APIs or other semantics.
+ * When these database features have quality issues, supporting them "corrupts"
+ * what might otherwise be a cleanly designed application.
+ * Similar issues can arise with any external system that your
+ * development team doesn't control, not just databases.
+ *
+ * <p>Solution Simplify database interactions by using
+ * the Active Record pattern.
+ * This pattern encapsulates database access logic within the
+ * domain model itself, allowing objects to be responsible
+ * for their own persistence.
+ * The Active Record pattern provides methods for
+ * CRUD operations directly within the model class,
+ * making database interactions straightforward and intuitive.
+ */
+
+package com.iluwatar.activerecord;