JdbcInventoryRepository.java

package org.jazzteam.fitnesclub.repository.jdbc;

import com.google.common.collect.Lists;
import lombok.extern.slf4j.Slf4j;
import org.jazzteam.fitnesclub.model.Inventory;
import org.jazzteam.fitnesclub.model.InventoryType;
import org.jazzteam.fitnesclub.repository.addictional.InventoryRepository;
import org.jazzteam.fitnesclub.repository.addictional.InventoryTypeRepository;
import org.jazzteam.fitnesclub.repository.addictional.impl.InventoryTypeRepositoryImpl;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

@Slf4j
public class JdbcInventoryRepository implements InventoryRepository {
    private InventoryTypeRepository inventoryTypeRepository = new InventoryTypeRepositoryImpl();

    @Override
    public Inventory findById(Long id) {
        try (Connection connection = ConnectionUtil.getConnection()) {
            return getInventoryById(id, connection);
        } catch (SQLException throwables) {
            log.debug("{}", throwables.getSQLState());
            log.debug("{}", throwables.getMessage());
            return null;
        }
    }

    @Override
    public Inventory save(Inventory inventory) {
        try (Connection connection = ConnectionUtil.getConnection()) {
            if (getInventoryById(inventory.getId(), connection) == null) {
                return saveNew(inventory, connection);
            }
            return update(inventory, connection);
        } catch (SQLException throwables) {
            log.debug("{}", throwables.getSQLState());
            log.debug("{}", throwables.getMessage());
            return null;
        }
    }

    @Override
    public void delete(Inventory inventory) {
        try (Connection connection = ConnectionUtil.getConnection()) {
            String deleteCommand = "delete from fitness_db.inventories where id = ?";

            PreparedStatement statement = connection.prepareStatement(deleteCommand, Statement.RETURN_GENERATED_KEYS);
            statement.setLong(1, inventory.getId());

            statement.execute();
        } catch (SQLException throwables) {
            log.error(throwables.getMessage());
            throw new IllegalStateException();
        }
    }

    @Override
    public List<Inventory> findAll() {
        List<Inventory> inventories = new ArrayList<>();
        try (Connection connection = ConnectionUtil.getConnection()) {

            String findCommand = "select id, type, amount from fitness_db.inventories";
            PreparedStatement statement = connection.prepareStatement(findCommand);
            ResultSet resultSet = statement.executeQuery();

            while (resultSet.next()) {
                Inventory inventory = getInventory(resultSet);
                inventories.add(inventory);
            }

        } catch (SQLException throwables) {
            log.error(throwables.getMessage());
        }
        return inventories;
    }

    @Override
    public List<Inventory> findAll(Predicate<Inventory> predicate) {

        List<Inventory> inventories = new ArrayList<>();
        try (Connection connection = ConnectionUtil.getConnection()) {
            String command = "select id, type, amount from fitness_db.inventories";
            PreparedStatement statement = connection.prepareStatement(command);
            ResultSet resultSet = statement.executeQuery();

            while (resultSet.next()) {
                Inventory inventory = getInventory(resultSet);
                if (predicate.test(inventory)) {
                    inventories.add(inventory);
                }
            }
        } catch (SQLException throwables) {
            log.error(throwables.getMessage());
        }
        return inventories;
    }

    @Override
    public List<Inventory> findByInventoryType(InventoryType inventoryType) {
        List<Inventory> inventories = new ArrayList<>();

        try (Connection connection = ConnectionUtil.getConnection()) {
            String command = "select id, type, amount from fitness_db.inventories where type = ?";

            PreparedStatement statement = connection.prepareStatement(command);
            statement.setLong(1, inventoryType.getId());
            ResultSet resultSet = statement.executeQuery();

            while (resultSet.next()) {
                Inventory inventory = getInventory(resultSet);
                inventories.add(inventory);
            }
        } catch (SQLException throwables) {
            log.error(throwables.getMessage());
        }
        return inventories;
    }

    private Inventory getInventory(ResultSet resultSet) throws SQLException {
        return new Inventory(
                resultSet.getLong("id"),
                inventoryTypeRepository.findById(resultSet.getLong("type")),
                resultSet.getInt("amount"),
                Lists.newArrayList());
    }

    private InventoryType getInventoryType(ResultSet resultSet) throws SQLException {
        return new InventoryType(
                resultSet.getLong("id"),
                resultSet.getString("type_name"),
                Lists.newArrayList(),
                Lists.newArrayList());
    }

    private Inventory getInventoryById(Long id, Connection connection) {
        log.debug("try find by id = {}", id);
        String sqlCommand = "select id, type, amount from fitness_db.inventories where id = ?";
        try (PreparedStatement statement = connection.prepareStatement(sqlCommand)) {
            statement.setLong(1, id);
            log.debug("{}", id);
            ResultSet resultSet = statement.executeQuery();
            if (resultSet.next()) {
                return getInventory(resultSet);
            }
        } catch (Exception e) {
            log.debug("Not found by id {}", id);
            return null;
        }
        return null;
    }

    private Inventory saveNew(Inventory inventory, Connection connection) throws SQLException {
        String saveCommand = "insert into fitness_db.inventories (type, amount) values (?, ?)";

        PreparedStatement statement = connection.prepareStatement(saveCommand, Statement.RETURN_GENERATED_KEYS);
        statement.setLong(1, inventory.getInventoryType().getId());
        statement.setInt(2, inventory.getAmount());

        int affectedRows = statement.executeUpdate();

        if (affectedRows == 0) {
            throw new IllegalArgumentException("Failed save inventory");
        }
        ResultSet generated = statement.getGeneratedKeys();
        if (generated.next()) {
            inventory.setId(generated.getLong(1));
        } else {
            connection.rollback();
            throw new IllegalArgumentException("No id obtained");
        }
        return getInventoryById(inventory.getId(), connection);
    }

    private Inventory update(Inventory inventory, Connection connection) throws SQLException {
        String updateCommand = "update FITNESS_DB.inventories set amount = ?, type = ? where id = ?";

        PreparedStatement statement = connection.prepareStatement(updateCommand, Statement.RETURN_GENERATED_KEYS);

        statement.setInt(1, inventory.getAmount());
        statement.setLong(2, inventory.getInventoryType().getId());
        statement.setLong(3, inventory.getId());
        int affectedRows = statement.executeUpdate();

        if (affectedRows == 0) {
            throw new IllegalArgumentException("Failed save inventory");
        }
        return getInventoryById(inventory.getId(), connection);
    }
}