Home work

pom.xml

@@ -17,6 +17,13 @@
             https://raw.githubusercontent.com/mate-academy/style-guides/master/java/checkstyle.xml
         </maven.checkstyle.plugin.configLocation>
     </properties>
+    <dependencies>
+        <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>8.0.33</version>
+        </dependency>
+    </dependencies>
 
     <build>
         <plugins>

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

@@ -1,7 +1,48 @@
 package mate.academy;
 
+import java.math.BigDecimal;
+import java.util.List;
+import java.util.Objects;
+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);
+
+        // Initialize data
+        List<Book> books = initializeBooks();
+        books.forEach(book -> System.out.println("Created record in DB: " + bookDao.create(book)));
+
+        // Fetch all books once and reuse the list
+        List<Book> allBooks = bookDao.findAll();
+        System.out.println(System.lineSeparator() + "Records in DB:");
+        allBooks.forEach(System.out::println);
+
+        // Update a specific book
+        allBooks.stream()
+                .filter(b -> Objects.equals(b.getTitle(), "Effective Java"))
+                .findFirst()
+                .ifPresent(updatedBook -> {
+                    updatedBook.setTitle("SQL in 10 Minutes");
+                    updatedBook.setPrice(BigDecimal.valueOf(24.99));
+                    System.out.println(System.lineSeparator()
+                            + "Updated in db: " + bookDao.update(updatedBook));
+                });
+
+        // Delete all books
+        allBooks.forEach(book -> System.out.println("Deleted record from DB: "
+                + bookDao.deleteById(book.getId())));
+    }
 
+    private static List<Book> initializeBooks() {
+        return List.of(
+                new Book("Core Java Volume I – Fundamentals", BigDecimal.valueOf(29.99)),
+                new Book("Effective Java", BigDecimal.valueOf(19.99)),
+                new Book("Java - The Complete Reference", BigDecimal.valueOf(35.45))
+        );
     }
 }

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 +1,107 @@
+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 query = "INSERT INTO books (title, price) "
+                + "VALUES (?, ?)";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection
+                        .prepareStatement(query, Statement.RETURN_GENERATED_KEYS)) {
+            statement.setString(1, book.getTitle());
+            statement.setBigDecimal(2, book.getPrice());
+            statement.executeUpdate();
+            ResultSet resultSet = statement.getGeneratedKeys();
+            if (resultSet.next()) {
+                book.setId(resultSet.getObject(1, Long.class));
+            }
+            return book;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Couldn't create book: " + book, e);
+        }
+    }
+
+    @Override
+    public Optional<Book> findById(Long id) {
+        String query = "SELECT id, title, price FROM books WHERE id = ?;";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(query)) {
+            statement.setLong(1, id);
+            ResultSet resultSet = statement.executeQuery();
+            Book book = null;
+            if (resultSet.next()) {
+                book = getBook(resultSet);
+                return Optional.of(book);
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Couldn't get book by id: " + id, e);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<Book> findAll() {
+        String query = "SELECT id, title, price FROM books";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(query)) {
+            List<Book> books = new ArrayList<>();
+            ResultSet resultSet = statement.executeQuery();
+            while (resultSet.next()) {
+                books.add(getBook(resultSet));
+            }
+            return books;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Couldn't get a list of books from books table.", e);
+        }
+    }
+
+    @Override
+    public Book update(Book book) {
+        String query = "UPDATE books SET title = ?, price = ? WHERE id= ?;";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(query)) {
+            statement.setString(1, book.getTitle());
+            statement.setBigDecimal(2, book.getPrice());
+            statement.setLong(3, book.getId());
+            statement.executeUpdate();
+            return book;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Couldn't update a book: "
+                    + book, e);
+        }
+    }
+
+    @Override
+    public boolean deleteById(Long id) {
+        String query = "DELETE FROM books WHERE id = ?";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(query)) {
+            statement.setLong(1, id);
+            return statement.executeUpdate() > 0;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Couldn't delete a book by id " + id, e);
+        }
+    }
+
+    private Book getBook(ResultSet resultSet) throws SQLException {
+        Long id = resultSet.getObject("id", Long.class);
+        String title = resultSet.getString("title");
+        BigDecimal price = resultSet.getBigDecimal("price");
+        return new Book(id, title, price);
+    }
+}

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 +1,76 @@
+package mate.academy.model;
+
+import java.math.BigDecimal;
+import java.util.Objects;
+
+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 Book(Long id, String title, BigDecimal price) {
+        this.id = id;
+        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 boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        Book book = (Book) o;
+        return Objects.equals(id, book.id)
+                && Objects.equals(title, book.title)
+                && Objects.equals(price, book.price);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, title, 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 URL = "jdbc:mysql://localhost:3306/library_service";
+    private static final String USERNAME = "root";
+    private static final String PASSWORD = "root";
+    private static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
+
+    static {
+        try {
+            Class.forName(JDBC_DRIVER);
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Can't find SQL Driver", e);
+        }
+    }
+
+    public static Connection getConnection() throws SQLException {
+        Properties dbProperties = new Properties();
+        dbProperties.setProperty("user", USERNAME);
+        dbProperties.setProperty("password", PASSWORD);
+        return DriverManager.getConnection(URL, dbProperties);
+    }
+}