From 9b98cc856bd2ab8c94b2b0ed50ad06cb015815ad Mon Sep 17 00:00:00 2001
From: Gwendal Margely <gwendal.margely.etu@univ-lille.fr>
Date: Thu, 14 Mar 2024 17:55:27 +0100
Subject: [PATCH] Improvement on Exceptions on DAO
---
WEB-INF/src/DAO/IngredientDAO.java | 125 +++++++++++-------
.../Exceptions/IngredientDAOException.java | 7 +
WEB-INF/src/Servlets/IngredientServlet.java | 2 +-
3 files changed, 84 insertions(+), 50 deletions(-)
create mode 100644 WEB-INF/src/Exceptions/IngredientDAOException.java
diff --git a/WEB-INF/src/DAO/IngredientDAO.java b/WEB-INF/src/DAO/IngredientDAO.java
index c700895..db01497 100644
--- a/WEB-INF/src/DAO/IngredientDAO.java
+++ b/WEB-INF/src/DAO/IngredientDAO.java
@@ -1,4 +1,5 @@
package DAO;
+import Exceptions.IngredientDAOException;
import POJO.Ingredient;
import java.sql.*;
@@ -20,79 +21,105 @@ public class IngredientDAO {
private static final String SELECT_ALL_QUERY = "SELECT * FROM ingredients";
private static final String INSERT_QUERY = "INSERT INTO ingredients(name, price) VALUES (?, ?)";
private static final String SELECT_BY_ID_QUERY = "SELECT * FROM ingredients WHERE id = ?";
+ private static final String DELETE_QUERY = "DELETE FROM ingredients WHERE id = ?";
// Method to establish database connection
- private static void connect() throws SQLException {
- connection = DriverManager.getConnection(url, user, password);
+ // Method to establish database connection
+ private static void connect() throws IngredientDAOException {
+ try {
+ connection = DriverManager.getConnection(url, user, password);
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error establishing database connection", e);
+ }
}
// Method to close database connection
- private static void close() throws SQLException {
- if (resultSet != null) {
- resultSet.close();
- }
- if (preparedStatement != null) {
- preparedStatement.close();
- }
- if (connection != null) {
- connection.close();
+ private static void close() throws IngredientDAOException {
+ try {
+ if (resultSet != null) {
+ resultSet.close();
+ }
+ if (preparedStatement != null) {
+ preparedStatement.close();
+ }
+ if (connection != null) {
+ connection.close();
+ }
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error closing database resources", e);
}
}
// Method to retrieve all ingredients from the database
- public static List<Ingredient> getAllIngredients() throws SQLException {
+ public List<Ingredient> getAllIngredients() throws IngredientDAOException {
List<Ingredient> ingredients = new ArrayList<>();
- connect();
- preparedStatement = connection.prepareStatement(SELECT_ALL_QUERY);
- resultSet = preparedStatement.executeQuery();
+ try {
+ connect();
+ preparedStatement = connection.prepareStatement(SELECT_ALL_QUERY);
+ resultSet = preparedStatement.executeQuery();
- while (resultSet.next()) {
- int id = resultSet.getInt("id");
- String name = resultSet.getString("name");
- double price = resultSet.getDouble("price");
- Ingredient ingredient = new Ingredient(id, name, price);
- ingredients.add(ingredient);
+ while (resultSet.next()) {
+ int id = resultSet.getInt("id");
+ String name = resultSet.getString("name");
+ double price = resultSet.getDouble("price");
+ Ingredient ingredient = new Ingredient(id, name, price);
+ ingredients.add(ingredient);
+ }
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error fetching ingredients", e);
+ } finally {
+ close();
}
-
- close();
return ingredients;
}
// Method to insert a new ingredient into the database
- public static void insertIngredient(Ingredient ingredient) throws SQLException {
- connect();
- preparedStatement = connection.prepareStatement(INSERT_QUERY);
- preparedStatement.setString(1, ingredient.getName());
- preparedStatement.setDouble(2, ingredient.getPrice());
- preparedStatement.executeUpdate();
- close();
+ public static void insertIngredient(Ingredient ingredient) throws IngredientDAOException {
+ try {
+ connect();
+ preparedStatement = connection.prepareStatement(INSERT_QUERY);
+ preparedStatement.setString(1, ingredient.getName());
+ preparedStatement.setDouble(2, ingredient.getPrice());
+ preparedStatement.executeUpdate();
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error inserting ingredient", e);
+ } finally {
+ close();
+ }
}
// Method to retrieve an ingredient by its ID
- public static Ingredient getIngredient(int id) throws SQLException {
- connect();
- preparedStatement = connection.prepareStatement(SELECT_BY_ID_QUERY);
- preparedStatement.setInt(1, id);
- resultSet = preparedStatement.executeQuery();
-
+ public static Ingredient getIngredient(int id) throws IngredientDAOException {
Ingredient ingredient = null;
- if (resultSet.next()) {
- String name = resultSet.getString("name");
- double price = resultSet.getDouble("price");
- ingredient = new Ingredient(id, name, price);
- }
+ try {
+ connect();
+ preparedStatement = connection.prepareStatement(SELECT_BY_ID_QUERY);
+ preparedStatement.setInt(1, id);
+ resultSet = preparedStatement.executeQuery();
- close();
+ if (resultSet.next()) {
+ String name = resultSet.getString("name");
+ double price = resultSet.getDouble("price");
+ ingredient = new Ingredient(id, name, price);
+ }
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error fetching ingredient", e);
+ } finally {
+ close();
+ }
return ingredient;
}
- public void deleteIngredient(int id) throws SQLException {
- String deleteQuery = "DELETE FROM ingredients WHERE id = ?";
- try (Connection connection = DriverManager.getConnection(url, user, password);
- PreparedStatement statement = connection.prepareStatement(deleteQuery)) {
- statement.setInt(1, id);
- statement.executeUpdate();
+ public void deleteIngredient(int id) throws IngredientDAOException {
+ try {
+ connect();
+ preparedStatement = connection.prepareStatement(DELETE_QUERY);
+ preparedStatement.setInt(1, id);
+ preparedStatement.executeUpdate();
+ } catch (SQLException e) {
+ throw new IngredientDAOException("Error deleting ingredient", e);
+ } finally {
+ close();
}
}
-
}
diff --git a/WEB-INF/src/Exceptions/IngredientDAOException.java b/WEB-INF/src/Exceptions/IngredientDAOException.java
new file mode 100644
index 0000000..e2e37a2
--- /dev/null
+++ b/WEB-INF/src/Exceptions/IngredientDAOException.java
@@ -0,0 +1,7 @@
+package Exceptions;
+
+public class IngredientDAOException extends Exception {
+ public IngredientDAOException(String message, Throwable cause) {
+ super(message, cause);
+ }
+}
diff --git a/WEB-INF/src/Servlets/IngredientServlet.java b/WEB-INF/src/Servlets/IngredientServlet.java
index 0df5ab9..30d81ee 100644
--- a/WEB-INF/src/Servlets/IngredientServlet.java
+++ b/WEB-INF/src/Servlets/IngredientServlet.java
@@ -4,7 +4,7 @@ package Servlets;
import DAO.IngredientDAO;
import POJO.Ingredient;
-import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.*;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
--
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