jv-jdbc task solution

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

@@ -1,7 +1,39 @@
 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");
+
     public static void main(String[] args) {
+        BookDao bookDao = (BookDao) injector.getInstance(BookDao.class);
+        List<Book> books = List.of(
+                new Book("Fire & Blood", new BigDecimal("7.99")),
+                new Book("A Game of Thrones", new BigDecimal("8.99")),
+                new Book("Cars", new BigDecimal("10.00"))
+        );
+
+        for (Book book: books) {
+            bookDao.create(book);
+        }
+
+        List<Book> getBooksFromDB = bookDao.findAll();
+
+        System.out.println(getBooksFromDB);
+
+        Optional<Book> optionalBookFromDb = bookDao.findById(getBooksFromDB.get(2).getId());
+
+        Book bookFromDb = getBooksFromDB.get(2);
+        bookFromDb.setPrice(new BigDecimal("40.99"));
+        bookFromDb.setTitle("Head First Java: A Brain-Friendly Guide");
+
+        bookDao.update(bookFromDb);
 
+        bookDao.deleteById(books.get(1).getId());
     }
 }

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 +1,120 @@
+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.lib.Dao;
+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) VALUE (?, ?)";
+        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 affectedRows = statement.executeUpdate();
+            if (affectedRows < 1) {
+                throw new RuntimeException(
+                        "Expected to insert at least one row, but inserted 0 rows.");
+            }
+
+            ResultSet generatedKeys = statement.getGeneratedKeys();
+            if (generatedKeys != null && generatedKeys.next()) {
+                Long id = generatedKeys.getObject(1, Long.class);
+                book.setId(id);
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't add new book into DB " + book);
+        }
+        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();
+            if (resultSet != null && resultSet.next()) {
+                return Optional.of(getBookFromResultSet(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to the DB");
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<Book> findAll() {
+        List<Book> books = new ArrayList<>();
+        String sql = "SELECT * FROM books";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            ResultSet resultSet = statement.executeQuery();
+            while (resultSet != null && resultSet.next()) {
+                books.add(getBookFromResultSet(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to the DB");
+        }
+        return books;
+    }
+
+    @Override
+    public Book update(Book book) {
+        String sql = "UPDATE books SET title = ?, price = ? WHERE id = ?";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            statement.setString(1, book.getTitle());
+            statement.setBigDecimal(2, book.getPrice());
+            statement.setLong(3, book.getId());
+
+            int affectedRows = statement.executeUpdate();
+            if (affectedRows < 1) {
+                throw new DataProcessingException(
+                        "Expected to insert at least one row, but inserted 0 rows.");
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to the DB");
+        }
+        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);
+            return statement.executeUpdate() > 0;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't create a connection to the DB");
+        }
+    }
+
+    private Book getBookFromResultSet(ResultSet resultSet) throws SQLException {
+        Long id = resultSet.getObject("id", Long.class);
+        String title = resultSet.getString("title");
+        BigDecimal price = resultSet.getObject("price", BigDecimal.class);
+
+        Book book = new Book();
+        book.setId(id);
+        book.setTitle(title);
+        book.setPrice(price);
+        return book;
+    }
+}

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

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 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/util/ConnectionUtil.java

@@ -0,0 +1,27 @@
+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/books";
+    private static final Properties DB_PROPERTIES;
+
+    static {
+        DB_PROPERTIES = new Properties();
+        DB_PROPERTIES.put("user", "WRITE_YOUR_DB_USERNAME");
+        DB_PROPERTIES.put("password", "WRITE_YOUR_DB_PASSWORD");
+
+        try {
+            Class.forName("com.mysql.cj.jdbc.Driver");
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Can't find MySQL driver", e);
+        }
+    }
+
+    public static Connection getConnection() throws SQLException {
+        return DriverManager.getConnection(DB_URL, DB_PROPERTIES);
+    }
+}

src/main/resources/init_db.sql

@@ -0,0 +1,5 @@
+CREATE TABLE books (
+    id BIGINT NOT NULL AUTO_INCREMENT,
+    title VARCHAR(255),
+    price DECIMAL(10, 2),
+    PRIMARY KEY(id));