hw is done, please check

pom.xml

@@ -18,6 +18,13 @@
         </maven.checkstyle.plugin.configLocation>
     </properties>
 
+    <dependencies>
+        <dependency>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
+            <version>9.0.0</version>
+        </dependency>
+    </dependencies>
     <build>
         <plugins>
             <plugin>

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

@@ -0,0 +1,39 @@
+package mate.academy;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
+
+public class ConnectionUtil {
+    private static String password;
+    private static final String DB_URL = "jdbc:mysql://localhost:3306/jdbc_intro";
+    private static final String USERNAME = "root";
+    private static final String PASSWORD_PATH = "src/main/resources/password.txt";
+    private static final Properties DB_PROPERTIES;
+
+    static {
+        try (BufferedReader bufferedReader = Files.newBufferedReader(Paths.get(PASSWORD_PATH))) {
+            password = bufferedReader.readLine();
+        } catch (IOException e) {
+            throw new RuntimeException("Can't read file", e);
+        }
+        DB_PROPERTIES = new Properties();
+        DB_PROPERTIES.put("user", USERNAME);
+        DB_PROPERTIES.put("password", password);
+
+        try {
+            Class.forName("com.mysql.cj.jdbc.Driver");
+        } catch (ClassNotFoundException e) {
+            throw new RuntimeException("Can not load JDBC driver", e);
+        }
+    }
+
+    public static Connection getConnection() throws SQLException {
+        return DriverManager.getConnection(DB_URL, DB_PROPERTIES);
+    }
+}

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

@@ -1,7 +1,35 @@
 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.getDaoInstance(BookDao.class);
+
+        Book book = new Book();
+        book.setTitle("NewTitle");
+        book.setPrice(BigDecimal.valueOf(40));
+        Book bookUpdated = bookDao.create(book);
+        System.out.println("Created: " + bookUpdated);
+
+        Optional<Book> findById = bookDao.findById(book.getId());
+        System.out.println("Found: " + findById);
+
+        List<Book> list = bookDao.findAll();
+        System.out.println("All lines: " + list);
+
+        book.setTitle("Updated title");
+        bookDao.update(book);
+        System.out.println("Updated: " + book);
 
+        boolean deleted = bookDao.deleteById(book.getId());
+        System.out.println("Deleted: " + deleted);
     }
 }

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

@@ -0,0 +1,19 @@
+package mate.academy.dao;
+
+import java.util.List;
+import java.util.Optional;
+import mate.academy.lib.Dao;
+import mate.academy.model.Book;
+
+@Dao
+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/impl/BookDaoImpl.java

@@ -0,0 +1,113 @@
+package mate.academy.dao.impl;
+
+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.ConnectionUtil;
+import mate.academy.dao.BookDao;
+import mate.academy.lib.Dao;
+import mate.academy.model.Book;
+import mate.academy.service.DataProcessingException;
+
+@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 affectedRows = statement.executeUpdate();
+            if (affectedRows == 0) {
+                throw new DataProcessingException("Expected to insert at least one row,"
+                        + " but inserted 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' add a new book with id: " + book.getId());
+        }
+        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.next()) {
+                return Optional.of(getBookFromResultSet(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't find a book with id: " + id);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<Book> findAll() {
+        List<Book> listOfBooks = new ArrayList<>();
+        String sql = "SELECT * FROM books;";
+        try (Connection connection = ConnectionUtil.getConnection();
+                PreparedStatement statement = connection.prepareStatement(sql)) {
+            ResultSet resultSet = statement.executeQuery();
+
+            while (resultSet.next()) {
+                listOfBooks.add(getBookFromResultSet(resultSet));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't retrieve all books from the database.");
+        }
+        return listOfBooks;
+    }
+
+    @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());
+            statement.executeUpdate();
+            return book;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't update the book with id: " + book.getId());
+        }
+    }
+
+    @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 delete the book with id: " + id);
+        }
+    }
+
+    private Book getBookFromResultSet(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/lib/Injector.java

@@ -12,7 +12,7 @@
 
 public class Injector {
     private static final Map<String, Injector> injectors = new HashMap<>();
-    private final List<Class<?>> classes = new ArrayList<>();
+    private static final List<Class<?>> classes = new ArrayList<>();
 
     private Injector(String mainPackageName) {
         try {
@@ -31,12 +31,12 @@ public static Injector getInstance(String mainPackageName) {
         return injector;
     }
 
-    public Object getInstance(Class<?> certainInterface) {
+    public static Object getDaoInstance(Class<?> certainInterface) {
         Class<?> clazz = findClassExtendingInterface(certainInterface);
         return createInstance(clazz);
     }
 
-    private Class<?> findClassExtendingInterface(Class<?> certainInterface) {
+    private static Class<?> findClassExtendingInterface(Class<?> certainInterface) {
         for (Class<?> clazz : classes) {
             Class<?>[] interfaces = clazz.getInterfaces();
             for (Class<?> singleInterface : interfaces) {
@@ -51,7 +51,7 @@ private Class<?> findClassExtendingInterface(Class<?> certainInterface) {
                 + " interface and has valid annotation (Dao or Service)");
     }
 
-    private Object createInstance(Class<?> clazz) {
+    private static Object createInstance(Class<?> clazz) {
         Object newInstance;
         try {
             Constructor<?> classConstructor = clazz.getConstructor();

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

@@ -0,0 +1,51 @@
+package mate.academy.model;
+
+import java.math.BigDecimal;
+
+public class Book {
+    private Long id;
+    private String title;
+    private BigDecimal price;
+
+    public Book() {
+    }
+
+    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 String toString() {
+        return "Book{"
+                + "id=" + id
+                + ", title='" + title + '\''
+                + ", price=" + price
+                + '}';
+    }
+}

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

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

src/main/resources/init_db.sql

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

src/main/resources/password.txt

@@ -0,0 +1 @@
+Nk102030!