created connection to DB and implemented DAO methods

pom.xml

@@ -18,6 +18,14 @@
         </maven.checkstyle.plugin.configLocation>
     </properties>
 
+    <dependencies>
+        <dependency>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
+            <version>8.4.0</version>
+        </dependency>
+    </dependencies>
+
     <build>
         <plugins>
             <plugin>

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

@@ -1,7 +1,65 @@
 package mate.academy;
 
+import java.math.BigDecimal;
+import java.util.List;
+import java.util.Optional;
+import mate.academy.dao.BookDao;
+import mate.academy.lib.Injector;
+import mate.academy.model.Book;
+
 public class Main {
+    private static final Injector injector = Injector.getInstance("mate.academy");
+    private static Book bookBeauty = new Book();
+    private static final Book bookPeace = new Book();
+    private static final Book bookFun = new Book();
+    private static BookDao bookDao;
+
+    static {
+        bookBeauty.setTitle("Beauty");
+        bookBeauty.setPrice(BigDecimal.valueOf(20.99));
+        bookPeace.setTitle("Peace");
+        bookPeace.setPrice(BigDecimal.valueOf(100.00));
+        bookFun.setTitle("Fun");
+        bookFun.setPrice(BigDecimal.valueOf(15.80));
+    }
+
     public static void main(String[] args) {
+        bookDao = (BookDao) injector.getInstance(BookDao.class);
+        Book bookBeautyWithId = createBook(bookBeauty);
+        System.out.println("Added new book to DB: " + bookBeautyWithId);
+        System.out.println("Added new book to DB: " + createBook(bookPeace));
+        System.out.println("Added new book to DB: " + createBook(bookFun));
+        Long bookBeautyId = bookBeautyWithId.getId();
+        Optional<Book> bookById = bookDao.findById(bookBeautyId);
+        System.out.println("Found book by id: " + bookBeautyId
+                + ". The book is: " + bookById);
+        List<Book> allBooks = bookDao.findAll();
+        System.out.println("List of all books: ");
+        outputAllBooksList(allBooks);
+        bookBeautyWithId.setPrice(BigDecimal.valueOf(25.00));
+        bookBeautyWithId.setTitle("BEAUTY");
+        bookDao.update(bookBeautyWithId);
+        System.out.println("Before updating, title: Beauty; price: 20.99. "
+                + "After updating should be: title: BEAUTY, price: 25.00. "
+                + System.lineSeparator() + "Updated book is: "
+                + bookDao.findById(bookBeautyId));
+        Long bookFunId = bookFun.getId();
+        bookDao.deleteById(bookFunId);
+        System.out.println("Deleted book with title \"Fun\", id: " + bookFunId);
+        List<Book> booksAfterDelete = bookDao.findAll();
+        System.out.println("List of all books after delete: ");
+        outputAllBooksList(booksAfterDelete);
+    }
+
+    private static Book createBook(Book book) {
+        return bookDao.create(bookBeauty);
+    }
 
+    private static void outputAllBooksList(List<Book> books) {
+        if (!books.isEmpty()) {
+            for (Book book : books) {
+                System.out.println(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 +1,116 @@
+package mate.academy.dao;
+
+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.lib.Dao;
+import mate.academy.model.Book;
+import mate.academy.service.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.create();
+                PreparedStatement statement
+                            = connection.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS)) {
+            statement.setString(1, book.getTitle());
+            statement.setObject(2, book.getPrice());
+            int affectedRows = statement.executeUpdate();
+            checkNumberOfAffectedRows(affectedRows);
+            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 new book in DB: "
+                    + book, e);
+        }
+        return book;
+    }
+
+    @Override
+    public Optional<Book> findById(Long id) {
+        String sql = "SELECT * FROM books WHERE id = ?";
+        try (Connection connection = ConnectionUtil.create();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            statement.setLong(1, id);
+            ResultSet resultSet = statement.executeQuery();
+            if (resultSet.next()) {
+                return Optional.of(mapResultSetToBook(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't find book by id = " + id, e);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<Book> findAll() {
+        String sql = "SELECT * FROM books";
+        List<Book> allBooks = new ArrayList<>();
+        try (Connection connection = ConnectionUtil.create();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            ResultSet resultSet = statement.executeQuery();
+            while (resultSet.next()) {
+                allBooks.add(mapResultSetToBook(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create List of all books in DB; ", e);
+        }
+        return allBooks;
+    }
+
+    @Override
+    public Book update(Book book) {
+        String sql = "UPDATE books SET title = ?, price = ? WHERE id = ?";
+        try (Connection connection = ConnectionUtil.create();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            statement.setString(1, book.getTitle());
+            statement.setBigDecimal(2, book.getPrice());
+            statement.setLong(3, book.getId());
+            int affectedRows = statement.executeUpdate();
+            checkNumberOfAffectedRows(affectedRows);
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't update info about book: "
+                    + book, e);
+        }
+        return book;
+    }
+
+    @Override
+    public boolean deleteById(Long id) {
+        String sql = "DELETE FROM books WHERE id = ?";
+        try (Connection connection = ConnectionUtil.create();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            statement.setLong(1, id);
+            int affectedRows = statement.executeUpdate();
+            return affectedRows > 0;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't delete book with id = "
+                    + id, e);
+        }
+    }
+
+    private Book mapResultSetToBook(ResultSet resultSet) throws SQLException {
+        Book book = new Book();
+        book.setId(resultSet.getObject("id", Long.class));
+        book.setTitle(resultSet.getString("title"));
+        book.setPrice(resultSet.getBigDecimal("price"));
+        return book;
+    }
+
+    private void checkNumberOfAffectedRows(int affectedRows) {
+        if (affectedRows < 1) {
+            throw new RuntimeException("Expected to modify at least 1 row, but modified 0 rows.");
+        }
+    }
+}

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 cause) {
+        super(message, cause);
+    }
+}

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

@@ -0,0 +1,42 @@
+package mate.academy.model;
+
+import java.math.BigDecimal;
+
+public class Book {
+    private Long id;
+    private String title;
+    private BigDecimal price;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public BigDecimal getPrice() {
+        return price;
+    }
+
+    public void setPrice(BigDecimal price) {
+        this.price = price;
+    }
+
+    @Override
+    public String toString() {
+        return "Book{"
+                + "id=" + id
+                + ", title='" + title + '\''
+                + ", price=" + price
+                + '}';
+    }
+}

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

@@ -0,0 +1,29 @@
+package mate.academy.service;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
+
+public class ConnectionUtil {
+    private static final String DB_USER_NAME = "root";
+    private static final String DB_PASSWORD = "getdataSQLjul";
+    private static final String DB_URL = "jdbc:mysql://localhost:3306/shop";
+    private static final String MYSQL_CLASS = "com.mysql.cj.jdbc.Driver";
+    private static final Properties DB_Properties;
+
+    static {
+        DB_Properties = new Properties();
+        DB_Properties.put("user", DB_USER_NAME);
+        DB_Properties.put("password", DB_PASSWORD);
+        try {
+            Class.forName(MYSQL_CLASS);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Cannot load MySQL JDBC driver class", e);
+        }
+    }
+
+    public static Connection create() throws SQLException {
+        return DriverManager.getConnection(DB_URL, DB_Properties);
+    }
+}

src/main/resources/init_db.sql

@@ -0,0 +1,6 @@
+CREATE TABLE books (
+    id BIGINT AUTO_INCREMENT,
+    title VARCHAR(255),
+    price DECIMAL(10, 2) NOT NULL,
+    PRIMARY KEY (id)
+);