维护入口

src/main/java/com/mzh/library/dao/impl/JdbcBookDao.java

@@ -33,6 +33,32 @@ public class JdbcBookDao implements BookDao {
         + "FROM book_categories "
         + "ORDER BY name";
 
+    private static final String FIND_CATEGORY_BY_ID = ""
+        + "SELECT id, name, description "
+        + "FROM book_categories "
+        + "WHERE id = ?";
+
+    private static final String FIND_CATEGORY_BY_NAME = ""
+        + "SELECT id, name, description "
+        + "FROM book_categories "
+        + "WHERE name = ?";
+
+    private static final String CREATE_CATEGORY = ""
+        + "INSERT INTO book_categories (name, description) "
+        + "VALUES (?, ?)";
+
+    private static final String UPDATE_CATEGORY = ""
+        + "UPDATE book_categories "
+        + "SET name = ?, description = ? "
+        + "WHERE id = ?";
+
+    private static final String DELETE_CATEGORY = "DELETE FROM book_categories WHERE id = ?";
+
+    private static final String COUNT_BOOKS_BY_CATEGORY = ""
+        + "SELECT COUNT(*) "
+        + "FROM books "
+        + "WHERE category_id = ?";
+
     private static final String FIND_BY_ID = "SELECT " + BOOK_COLUMNS + BOOK_FROM + "WHERE b.id = ?";
 
     private static final String FIND_BY_IDENTIFIER = "SELECT " + BOOK_COLUMNS + BOOK_FROM
@@ -66,6 +92,86 @@ public class JdbcBookDao implements BookDao {
         }
     }
 
+    @Override
+    public Optional<BookCategory> findCategoryById(long id) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(FIND_CATEGORY_BY_ID)) {
+            statement.setLong(1, id);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                return resultSet.next() ? Optional.of(mapCategory(resultSet)) : Optional.empty();
+            }
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to load book category by id", ex);
+        }
+    }
+
+    @Override
+    public Optional<BookCategory> findCategoryByName(String name) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(FIND_CATEGORY_BY_NAME)) {
+            statement.setString(1, name);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                return resultSet.next() ? Optional.of(mapCategory(resultSet)) : Optional.empty();
+            }
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to load book category by name", ex);
+        }
+    }
+
+    @Override
+    public long createCategory(BookCategory category) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(CREATE_CATEGORY, Statement.RETURN_GENERATED_KEYS)) {
+            bindCategory(statement, category);
+            statement.executeUpdate();
+
+            try (ResultSet generatedKeys = statement.getGeneratedKeys()) {
+                if (generatedKeys.next()) {
+                    return generatedKeys.getLong(1);
+                }
+            }
+            throw new DaoException("Unable to read generated book category id", null);
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to create book category", ex);
+        }
+    }
+
+    @Override
+    public boolean updateCategory(BookCategory category) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(UPDATE_CATEGORY)) {
+            bindCategory(statement, category);
+            statement.setLong(3, category.getId());
+            return statement.executeUpdate() == 1;
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to update book category", ex);
+        }
+    }
+
+    @Override
+    public boolean deleteCategory(long id) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(DELETE_CATEGORY)) {
+            statement.setLong(1, id);
+            return statement.executeUpdate() == 1;
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to delete book category", ex);
+        }
+    }
+
+    @Override
+    public int countBooksByCategoryId(long categoryId) {
+        try (Connection connection = JdbcUtil.getConnection();
+             PreparedStatement statement = connection.prepareStatement(COUNT_BOOKS_BY_CATEGORY)) {
+            statement.setLong(1, categoryId);
+            try (ResultSet resultSet = statement.executeQuery()) {
+                return resultSet.next() ? resultSet.getInt(1) : 0;
+            }
+        } catch (SQLException ex) {
+            throw new DaoException("Unable to count books by category", ex);
+        }
+    }
+
     @Override
     public List<Book> search(BookSearchCriteria criteria) {
         List<Object> parameters = new ArrayList<>();
@@ -194,6 +300,11 @@ public class JdbcBookDao implements BookDao {
         statement.setString(7, book.getStatus().getCode());
     }
 
+    private void bindCategory(PreparedStatement statement, BookCategory category) throws SQLException {
+        statement.setString(1, category.getName());
+        statement.setString(2, category.getDescription());
+    }
+
     private Book mapBook(ResultSet resultSet) throws SQLException {
         Book book = new Book();
         book.setId(resultSet.getLong("id"));