connected to DB, implemented DAO

pom.xml

@@ -55,4 +55,13 @@
             </plugins>
         </pluginManagement>
     </build>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
+            <version>8.4.0</version>
+        </dependency>
+    </dependencies>
+
 </project>

src/main/java/mate/academy/Main.java

@@ -1,7 +1,36 @@
 package mate.academy;
 
+import java.math.BigDecimal;
+import java.util.List;
+import mate.academy.dao.BookDao;
+import mate.academy.lib.Injector;
+import mate.academy.model.Book;
+
 public class Main {
-    public static void main(String[] args) {
+    private static final Injector injector = Injector.getInstance("mate.academy");
 
+    public static void main(String[] args) {
+        BookDao bookDao = (BookDao) injector.getInstance(BookDao.class);
+        List<Book> books = List.of(
+                new Book("Whats the Point of Maths?",
+                        BigDecimal.valueOf(200)),
+                new Book("Upstream Intermediate Workbook",
+                        BigDecimal.valueOf(350)),
+                new Book("See Inside Your Body",
+                        BigDecimal.valueOf(400)),
+                new Book("Henry Ford: My life and My work",
+                        BigDecimal.valueOf(250)),
+                new Book("GCSE Edexcel Mathematics for the Grade 9-1 Course",
+                        BigDecimal.valueOf(350))
+        );
+        for (Book book : books) {
+            bookDao.create(book);
+        }
+        System.out.println(bookDao.findById(3L));
+        System.out.println(bookDao.deleteById(5L));
+        System.out.println(bookDao.findAll().toString());
+        Book book = books.get(4);
+        book.setPrice(BigDecimal.valueOf(225));
+        System.out.println(bookDao.update(book));
     }
 }

src/main/java/mate/academy/dao/BookDao.java

@@ -0,0 +1,17 @@
+package mate.academy.dao;
+
+import java.util.List;
+import java.util.Optional;
+import mate.academy.model.Book;
+
+public interface BookDao {
+    Book create(Book book);
+
+    Optional<Book> findById(Long id);
+
+    List<Book> findAll();
+
+    Book update(Book book);
+
+    boolean deleteById(Long id);
+}

src/main/java/mate/academy/dao/BookDaoImpl.java

@@ -0,0 +1,129 @@
+package mate.academy.dao;
+
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import mate.academy.exception.DataProcessingException;
+import mate.academy.model.Book;
+import mate.academy.util.ConnectionUtil;
+
+@Dao
+public class BookDaoImpl implements BookDao {
+    @Override
+    public Book create(Book book) {
+        String sql = "INSERT INTO books (title, price) VALUES (?, ?)";
+        try (Connection connection = ConnectionUtil.getConnection();
+                        PreparedStatement statement =
+                            connection.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) {
+
+            statement.setString(1, book.getTitle());
+            statement.setBigDecimal(2, book.getPrice());
+            int updatedRows = statement.executeUpdate();
+            if (updatedRows < 1) {
+                throw new RuntimeException(
+                        "expected to insert at least one row, but instead 0 rows"
+                );
+            }
+            ResultSet generatedKeys = statement.getGeneratedKeys();
+            if (generatedKeys.next()) {
+                Long id = generatedKeys.getObject(1, Long.class);
+                book.setId(id);
+            }
+
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to a DB", e);
+        }
+        return book;
+    }
+
+    @Override
+    public Optional<Book> findById(Long id) {
+        String sql = "SELECT * FROM books WHERE id = ?";
+
+        try (Connection connection = ConnectionUtil.getConnection();
+                        PreparedStatement statement = connection.prepareStatement(sql)) {
+
+            statement.setLong(1, id);
+            ResultSet resultSet = statement.executeQuery();
+            List<Book> list = mappingResSet(resultSet);
+
+            if (!list.isEmpty()) {
+                return Optional.of(list.get(0));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to a DB", e);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<Book> findAll() {
+        String sql = "SELECT * FROM books";
+
+        try (Connection connection = ConnectionUtil.getConnection();
+                        PreparedStatement statement = connection.prepareStatement(sql)) {
+
+            ResultSet resultSet = statement.executeQuery();
+            return mappingResSet(resultSet);
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to a DB", e);
+        }
+    }
+
+    @Override
+    public Book update(Book book) {
+        String sql = "UPDATE books SET price = ? WHERE title = ?";
+        try (Connection connection = ConnectionUtil.getConnection();
+                        PreparedStatement statement = connection.prepareStatement(sql)) {
+
+            statement.setBigDecimal(1, book.getPrice());
+            statement.setString(2, book.getTitle());
+            int updatedRows = statement.executeUpdate();
+            if (updatedRows < 1) {
+                throw new RuntimeException(
+                        "expected to update at least one row, but instead 0 rows"
+                );
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to a DB", e);
+        }
+        return book;
+    }
+
+    @Override
+    public boolean deleteById(Long id) {
+        String sql = "DELETE FROM books WHERE id = ?";
+
+        try (Connection connection = ConnectionUtil.getConnection();
+                        PreparedStatement statement = connection.prepareStatement(sql)) {
+
+            statement.setLong(1, id);
+            int updatedRows = statement.executeUpdate();
+            return updatedRows > 0;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to a DB", e);
+        }
+    }
+
+    private List<Book> mappingResSet(ResultSet resultSet) throws SQLException {
+        List<Book> books = new ArrayList<>();
+        while (resultSet.next()) {
+            long id = resultSet.getObject("id", Long.class);
+            String title = resultSet.getString("title");
+            BigDecimal price = resultSet.getBigDecimal("price");
+
+            Book book = new Book();
+            book.setId(id);
+            book.setTitle(title);
+            book.setPrice(price);
+            books.add(book);
+        }
+        return books;
+    }
+}

src/main/java/mate/academy/lib/Dao.java → src/main/java/mate/academy/dao/Dao.java

@@ -1,4 +1,4 @@
-package mate.academy.lib;
+package mate.academy.dao;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

src/main/java/mate/academy/exception/DataProcessingException.java

@@ -0,0 +1,7 @@
+package mate.academy.exception;
+
+public class DataProcessingException extends RuntimeException {
+    public DataProcessingException(String message, Throwable ex) {
+        super(message, ex);
+    }
+}

src/main/java/mate/academy/lib/Injector.java

@@ -9,6 +9,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import mate.academy.dao.Dao;
 
 public class Injector {
     private static final Map<String, Injector> injectors = new HashMap<>();

src/main/java/mate/academy/model/Book.java

@@ -0,0 +1,50 @@
+package mate.academy.model;
+
+import java.math.BigDecimal;
+
+public class Book {
+    private Long id;
+    private String title;
+    private BigDecimal price;
+
+    public Book() {
+    }
+
+    public Book(String title, BigDecimal price) {
+        this.title = title;
+        this.price = price;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public void setPrice(BigDecimal price) {
+        this.price = price;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public BigDecimal getPrice() {
+        return price;
+    }
+
+    @Override
+    public String toString() {
+        return "Book{"
+                + "id=" + id
+                + ", title='" + title + '\''
+                + ", price=" + price
+                + '}';
+    }
+}

src/main/java/mate/academy/util/ConnectionUtil.java

@@ -0,0 +1,28 @@
+package mate.academy.util;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
+
+public class ConnectionUtil {
+    private static final String DB_URL = "jdbc:mysql://localhost:3306/task";
+
+    private static final Properties DB_PROPERTIES;
+
+    static {
+        DB_PROPERTIES = new Properties();
+        DB_PROPERTIES.put("user", "root");
+        DB_PROPERTIES.put("password", "1987");
+
+        try {
+            Class.forName("com.mysql.cj.jdbc.Driver");
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Can't load JDBC driver", e);
+        }
+    }
+
+    public static Connection getConnection() throws SQLException {
+        return DriverManager.getConnection(DB_URL, DB_PROPERTIES);
+    }
+}

src/main/resources/init_db.sql

@@ -0,0 +1,22 @@
+CREATE TABLE `books` (
+`id` BIGINT AUTO_INCREMENT,
+`title` VARCHAR(255),
+`price` INT,
+PRIMARY KEY (`id`)
+);
+
+INSERT INTO books (title, price) VALUES(
+'Whats the Point of Maths?', 200
+);
+INSERT INTO books (title, price) VALUES(
+'Upstream Intermediate Workbook', 350
+);
+INSERT INTO books (title, price) VALUES(
+'See Inside Your Body', 400
+);
+INSERT INTO books (title, price) VALUES(
+'Henry Ford: My life and My work', 250
+);
+INSERT INTO books (title, price) VALUES(
+'GCSE Edexcel Mathematics for the Grade 9-1 Course', 350
+);