jdbc-intro

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

@@ -0,0 +1,36 @@
+package mate.academy;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
+
+public class ConnectionUtil {
+    private static final String PROPERTIES_FILE_PATH = "src/main/resources/db.properties";
+    private static final String DATABASE_URL = "db.url";
+    private static final String DATABASE_USER_NAME = "db.username";
+    private static final String DATABASE_USER_PASSWORD = "db.password";
+    private static final Properties properties = new Properties();
+
+    static {
+        readDatabaseFileProperties();
+    }
+
+    private static final void readDatabaseFileProperties() {
+        try (InputStream inputStreamProperties = new FileInputStream(PROPERTIES_FILE_PATH)) {
+            properties.load(inputStreamProperties);
+        } catch (IOException e) {
+            throw new RuntimeException("Cannot read properties file", e);
+        }
+    }
+
+    public static Connection connectToDatabase() throws SQLException {
+        String url = properties.getProperty(DATABASE_URL);
+        String username = properties.getProperty(DATABASE_USER_NAME);
+        String password = properties.getProperty(DATABASE_USER_PASSWORD);
+        return DriverManager.getConnection(url, username, password);
+    }
+}

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

@@ -1,7 +1,21 @@
 package mate.academy;
 
+import java.math.BigDecimal;
+import mate.academy.dao.BookDao;
+import mate.academy.domain.Book;
+import mate.academy.lib.Injector;
+
 public class Main {
-    public static void main(String[] args) {
+    private static final Injector injector = Injector.getInstance("mate.academy.dao");
 
+    public static void main(String[] args) {
+        BookDao bookDao = (BookDao) injector.getInstance(BookDao.class);
+        Book book = new Book("The witcher", new BigDecimal("195.00"));
+        bookDao.create(book);
+        bookDao.create(book);
+        bookDao.update(book);
+        bookDao.deleteById(1);
+        bookDao.findAll();
+        bookDao.findById(2);
     }
 }

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

@@ -0,0 +1,18 @@
+package mate.academy.dao;
+
+import java.util.List;
+import java.util.Optional;
+import mate.academy.domain.Book;
+
+public interface BookDao {
+
+    Book create(Book book);
+
+    Optional<Book> findById(int id);
+
+    List<Book> findAll();
+
+    Book update(Book book);
+
+    boolean deleteById(int id);
+}

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

@@ -0,0 +1,123 @@
+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.ConnectionUtil;
+import mate.academy.domain.Book;
+import mate.academy.lib.Dao;
+
+@Dao
+public class BookDaoImpl implements BookDao {
+    private static final String CREATE_BOOK_QUERY = "INSERT INTO book (title, price) VALUES (?, ?)";
+    private static final String FIND_BOOK_BY_ID_QUERY = "SELECT * FROM book WHERE id = ?";
+    private static final String FIND_ALL_BOOK_QUERY = "SELECT * FROM book";
+    private static final String UPDATE_BOOK_QUERY = "UPDATE book SET title = ?, "
+            + "price = ? WHERE id = ?";
+    private static final String DELETE_BOOK_QUERY = "DELETE FROM book WHERE id = ?";
+
+    @Override
+    public Book create(Book book) {
+        Book createdBook;
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement = connection.prepareStatement(CREATE_BOOK_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+            preparedStatement.setString(2, book.getTitle());
+            preparedStatement.setBigDecimal(3, book.getPrice());
+            preparedStatement.execute();
+            try (ResultSet resultSet = preparedStatement.getGeneratedKeys()) {
+                resultSet.next();
+                createdBook = new Book(
+                        resultSet.getString("title"),
+                        resultSet.getBigDecimal("price"));
+            }
+        } catch (SQLException throwables) {
+            throw new RuntimeException(throwables);
+        }
+        return createdBook;
+    }
+
+    @Override
+    public Optional<Book> findById(int id) {
+        Book findBookById = null;
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(FIND_BOOK_BY_ID_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+            preparedStatement.setLong(1, id);
+            ResultSet resultSet = preparedStatement.executeQuery();
+            while (resultSet.next()) {
+                Long bookId = resultSet.getLong("id");
+                String title = resultSet.getString("title");
+                BigDecimal price = resultSet.getBigDecimal("price");
+                findBookById = new Book(bookId, title, price);
+            }
+        } catch (SQLException throwables) {
+            throw new RuntimeException(throwables);
+        }
+        return Optional.ofNullable(findBookById);
+    }
+
+    @Override
+    public List<Book> findAll() {
+        List<Book> foundBooks = new ArrayList<>();
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(FIND_ALL_BOOK_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+
+            ResultSet resultSet = preparedStatement.executeQuery();
+            while (resultSet.next()) {
+                Long bookId = resultSet.getLong("id");
+                String title = resultSet.getString("title");
+                BigDecimal price = resultSet.getBigDecimal("price");
+                foundBooks.add(new Book(bookId, title, price));
+            }
+        } catch (SQLException throwables) {
+            throw new RuntimeException(throwables);
+        }
+        return foundBooks;
+    }
+
+    @Override
+    public Book update(Book book) {
+        Book updatedBook = null;
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement = connection.prepareStatement(UPDATE_BOOK_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+            preparedStatement.setString(2, book.getTitle());
+            preparedStatement.setBigDecimal(3, book.getPrice());
+            ResultSet resultSet = preparedStatement.executeQuery();
+            while (resultSet.next()) {
+                Long bookId = resultSet.getLong("id");
+                String title = resultSet.getString("title");
+                BigDecimal price = resultSet.getBigDecimal("price");
+                updatedBook = new Book(bookId, title, price);
+            }
+        } catch (SQLException throwables) {
+            throw new RuntimeException(throwables);
+        }
+        return updatedBook;
+    }
+
+    @Override
+    public boolean deleteById(int id) {
+        boolean isDeleted;
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement = connection.prepareStatement(DELETE_BOOK_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+            preparedStatement.setLong(1, id);
+            isDeleted = preparedStatement.execute();
+        } catch (SQLException throwables) {
+            throw new RuntimeException(throwables);
+        }
+        return isDeleted;
+    }
+}
+

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

@@ -0,0 +1,47 @@
+package mate.academy.domain;
+
+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 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;
+    }
+}

src/main/resources/db.properties

@@ -0,0 +1,3 @@
+db.url=jdbc:mysql://localhost:3307
+db.username=postgres
+db.password=root

src/main/resources/init_db.sql

@@ -0,0 +1,7 @@
+create schema if not exists test;
+
+create table if not exists book (
+    book_id serial primary key,
+    title varchar(20),
+    price decimal
+);