jdbc-intro

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

@@ -0,0 +1,36 @@
+package mate.academy.util;
+
+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/util/Main.java

@@ -0,0 +1,21 @@
+package mate.academy.util;
+
+import java.math.BigDecimal;
+import mate.academy.util.dao.BookDao;
+import mate.academy.util.domain.Book;
+import mate.academy.util.lib.Injector;
+
+public class Main {
+    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/util/dao/BookDao.java

@@ -0,0 +1,17 @@
+package mate.academy.util.dao;
+
+import java.util.List;
+import java.util.Optional;
+import mate.academy.util.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/util/dao/BookDaoImpl.java

@@ -0,0 +1,135 @@
+package mate.academy.util.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.util.ConnectionUtil;
+import mate.academy.util.domain.Book;
+import mate.academy.util.exception.DataProcessingException;
+import mate.academy.util.lib.Dao;
+
+@Dao
+public class BookDaoImpl implements BookDao {
+    private static final String CREATE_BOOK_QUERY = "INSERT INTO book (id, 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) {
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement = connection.prepareStatement(CREATE_BOOK_QUERY,
+                        Statement.RETURN_GENERATED_KEYS)) {
+            preparedStatement.setLong(1, book.getId());
+            preparedStatement.setString(2, book.getTitle());
+            preparedStatement.setBigDecimal(3, book.getPrice());
+            preparedStatement.execute();
+            int affectedRows = preparedStatement.executeUpdate();
+            if (affectedRows < 1) {
+                throw new DataProcessingException(
+                        "Expected to insert at least 1 row, but was 0");
+            }
+            try (ResultSet generatedKeys = preparedStatement.getGeneratedKeys()) {
+                if (generatedKeys.next()) {
+                    Long id = generatedKeys.getObject(1, Long.class);
+                    book.setId(id);
+                }
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't add a new book" + book, e);
+        }
+        return book;
+    }
+
+    @Override
+    public Optional<Book> findById(int id) {
+        Optional<Book> findBookById = Optional.empty();
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(FIND_BOOK_BY_ID_QUERY)) {
+            preparedStatement.setLong(1, id);
+            ResultSet resultSet = preparedStatement.executeQuery();
+            if (resultSet.next()) {
+                findBookById = Optional.of(mapResutSetToBook(resultSet, id));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't find book by id" + id, e);
+        }
+        return findBookById;
+    }
+
+    @Override
+    public List<Book> findAll() {
+        List<Book> books = new ArrayList<>();
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(FIND_ALL_BOOK_QUERY)) {
+
+            ResultSet resultSet = preparedStatement.executeQuery();
+            while (resultSet.next()) {
+                Long bookId = resultSet.getLong("id");
+                books.add(mapResutSetToBook(resultSet, bookId));
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't find all books", e);
+        }
+        return books;
+    }
+
+    @Override
+    public Book update(Book book) {
+        Book updatedBook = book;
+        try (Connection connection =
+                     ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(UPDATE_BOOK_QUERY)) {
+            preparedStatement.setLong(1, book.getId());
+            preparedStatement.setString(2, book.getTitle());
+            preparedStatement.setBigDecimal(3, book.getPrice());
+            ResultSet resultSet = preparedStatement.executeQuery();
+            while (resultSet.next()) {
+                String title = resultSet.getString("title");
+                BigDecimal price = resultSet.getBigDecimal("price");
+                updatedBook.setTitle(title);
+                updatedBook.setPrice(price);
+            }
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't update book: " + book, e);
+        }
+        return updatedBook;
+    }
+
+    @Override
+    public boolean deleteById(int id) {
+        try (Connection connection = ConnectionUtil.connectToDatabase();
+                PreparedStatement preparedStatement =
+                        connection.prepareStatement(DELETE_BOOK_QUERY)) {
+            preparedStatement.setLong(1, id);
+            return preparedStatement.executeUpdate() > 0;
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't delete book by id: " + id, e);
+        }
+    }
+
+    private Book mapResutSetToBook(ResultSet resultSet, long id) {
+        Book book;
+        try {
+            String title = resultSet.getString("title");
+            BigDecimal price = resultSet.getBigDecimal("price");
+            book = new Book(id, title, price);
+        } catch (SQLException e) {
+            throw new DataProcessingException("Can't map result set to book: " + resultSet, e);
+        }
+        return book;
+    }
+}
+

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

@@ -0,0 +1,60 @@
+package mate.academy.util.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;
+    }
+
+    @Override
+    public String toString() {
+        return "Book{"
+                + "id="
+                + id
+                + ", title='"
+                + title
+                + '\''
+                + ", price="
+                + price
+                + '}';
+    }
+}

src/main/java/mate/academy/util/exception/DataProcessingException.java

@@ -0,0 +1,11 @@
+package mate.academy.util.exception;
+
+public class DataProcessingException extends RuntimeException {
+    public DataProcessingException(String message) {
+        super(message);
+    }
+
+    public DataProcessingException(String message, Throwable cause) {
+        super(message);
+    }
+}

src/main/java/mate/academy/lib/Dao.java → src/main/java/mate/academy/util/lib/Dao.java

@@ -1,4 +1,4 @@
-package mate.academy.lib;
+package mate.academy.util.lib;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

src/main/java/mate/academy/lib/Injector.java → src/main/java/mate/academy/util/lib/Injector.java

@@ -1,4 +1,4 @@
-package mate.academy.lib;
+package mate.academy.util.lib;
 
 import java.io.File;
 import java.io.IOException;

src/main/resources/db.properties

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

src/main/resources/init_db.sql

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