مشروع: تطبيق ويب لإدارة البيانات بنمط DAO

product-catalogue/ ├── pom.xml └── src/main/ ├── java/com/example/catalogue/ │ ├── db/ DataSourceProvider.java │ ├── model/ Product.java │ ├── dao/ ProductDao.java (interface) │ │ ProductDaoImpl.java │ ├── service/ ProductService.java │ └── servlet/ ProductServlet.java └── webapp/ ├── WEB-INF/ │ ├── web.xml │ └── views/ │ ├── list.jsp │ ├── form.jsp │ └── error.jsp └── index.jsp (يُعيد التوجيه إلى /products)

package com.example.catalogue.model; public class Product { private int id; private String name; private String sku; private double price; private int stock; public Product() {} public Product(int id, String name, String sku, double price, int stock) { this.id = id; this.name = name; this.sku = sku; this.price = price; this.stock = stock; } // الـ getters والـ setters المعتادة محذوفة للإيجاز public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String n) { this.name = n; } public String getSku() { return sku; } public void setSku(String s) { this.sku = s; } public double getPrice() { return price; } public void setPrice(double p) { this.price = p; } public int getStock() { return stock; } public void setStock(int s) { this.stock = s; } }

package com.example.catalogue.dao; import com.example.catalogue.model.Product; import java.sql.SQLException; import java.util.List; public interface ProductDao { List<Product> findAll() throws SQLException; Product findById(int id) throws SQLException; void insert(Product p) throws SQLException; void update(Product p) throws SQLException; void delete(int id) throws SQLException; }

package com.example.catalogue.dao; import com.example.catalogue.model.Product; import javax.sql.DataSource; import java.sql.*; import java.util.ArrayList; import java.util.List; public class ProductDaoImpl implements ProductDao { private final DataSource ds; public ProductDaoImpl(DataSource ds) { this.ds = ds; } // ---- مساعدات ---------------------------------------- private Product map(ResultSet rs) throws SQLException { return new Product( rs.getInt("id"), rs.getString("name"), rs.getString("sku"), rs.getDouble("price"), rs.getInt("stock") ); } // ---- CRUD ------------------------------------------- @Override public List<Product> findAll() throws SQLException { String sql = "SELECT id, name, sku, price, stock FROM products ORDER BY name"; List<Product> list = new ArrayList<>(); try (Connection c = ds.getConnection(); PreparedStatement ps = c.prepareStatement(sql); ResultSet rs = ps.executeQuery()) { while (rs.next()) list.add(map(rs)); } return list; } @Override public Product findById(int id) throws SQLException { String sql = "SELECT id, name, sku, price, stock FROM products WHERE id = ?"; try (Connection c = ds.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) { ps.setInt(1, id); try (ResultSet rs = ps.executeQuery()) { return rs.next() ? map(rs) : null; } } } @Override public void insert(Product p) throws SQLException { String sql = "INSERT INTO products (name, sku, price, stock) VALUES (?, ?, ?, ?)"; try (Connection c = ds.getConnection(); PreparedStatement ps = c.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS)) { ps.setString(1, p.getName()); ps.setString(2, p.getSku()); ps.setDouble(3, p.getPrice()); ps.setInt(4, p.getStock()); ps.executeUpdate(); try (ResultSet keys = ps.getGeneratedKeys()) { if (keys.next()) p.setId(keys.getInt(1)); } } } @Override public void update(Product p) throws SQLException { String sql = "UPDATE products SET name=?, sku=?, price=?, stock=? WHERE id=?"; try (Connection c = ds.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) { ps.setString(1, p.getName()); ps.setString(2, p.getSku()); ps.setDouble(3, p.getPrice()); ps.setInt(4, p.getStock()); ps.setInt(5, p.getId()); ps.executeUpdate(); } } @Override public void delete(int id) throws SQLException { String sql = "DELETE FROM products WHERE id = ?"; try (Connection c = ds.getConnection(); PreparedStatement ps = c.prepareStatement(sql)) { ps.setInt(1, id); ps.executeUpdate(); } } }

package com.example.catalogue.service; import com.example.catalogue.dao.ProductDao; import com.example.catalogue.model.Product; import java.sql.SQLException; import java.util.List; public class ProductService { private final ProductDao dao; public ProductService(ProductDao dao) { this.dao = dao; } public List<Product> listAll() throws SQLException { return dao.findAll(); } public Product getById(int id) throws SQLException { Product p = dao.findById(id); if (p == null) throw new IllegalArgumentException("Product not found: " + id); return p; } public void create(Product p) throws SQLException { validate(p); dao.insert(p); } public void edit(Product p) throws SQLException { validate(p); dao.update(p); } public void remove(int id) throws SQLException { dao.delete(id); } private void validate(Product p) { if (p.getName() == null || p.getName().isBlank()) throw new IllegalArgumentException("الاسم مطلوب."); if (p.getSku() == null || p.getSku().isBlank()) throw new IllegalArgumentException("رقم SKU مطلوب."); if (p.getPrice() < 0) throw new IllegalArgumentException("لا يمكن أن يكون السعر سالبًا."); } }

package com.example.catalogue.servlet; import com.example.catalogue.dao.ProductDaoImpl; import com.example.catalogue.db.DataSourceProvider; import com.example.catalogue.model.Product; import com.example.catalogue.service.ProductService; import jakarta.servlet.ServletException; import jakarta.servlet.annotation.WebServlet; import jakarta.servlet.http.HttpServlet; import jakarta.servlet.http.HttpServletRequest; import jakarta.servlet.http.HttpServletResponse; import java.io.IOException; import java.sql.SQLException; @WebServlet(urlPatterns = "/products", loadOnStartup = 1) public class ProductServlet extends HttpServlet { private ProductService service; @Override public void init() throws ServletException { try { service = new ProductService( new ProductDaoImpl(DataSourceProvider.get()) ); } catch (Exception e) { throw new ServletException("فشل تهيئة الخدمة", e); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String action = req.getParameter("action"); if (action == null) action = "list"; try { switch (action) { case "new" -> showForm(req, resp, new Product()); case "edit" -> showEditForm(req, resp); case "delete" -> handleDelete(req, resp); default -> showList(req, resp); } } catch (SQLException | IllegalArgumentException e) { req.setAttribute("error", e.getMessage()); req.getRequestDispatcher("/WEB-INF/views/error.jsp").forward(req, resp); } } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String action = req.getParameter("action"); try { if ("create".equals(action)) handleCreate(req, resp); else if ("update".equals(action)) handleUpdate(req, resp); } catch (SQLException | IllegalArgumentException e) { req.setAttribute("error", e.getMessage()); req.getRequestDispatcher("/WEB-INF/views/error.jsp").forward(req, resp); } } // ---- مساعدات خاصة -------------------------------- private void showList(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException, SQLException { req.setAttribute("products", service.listAll()); req.getRequestDispatcher("/WEB-INF/views/list.jsp").forward(req, resp); } private void showForm(HttpServletRequest req, HttpServletResponse resp, Product p) throws ServletException, IOException { req.setAttribute("product", p); req.getRequestDispatcher("/WEB-INF/views/form.jsp").forward(req, resp); } private void showEditForm(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException, SQLException { int id = Integer.parseInt(req.getParameter("id")); showForm(req, resp, service.getById(id)); } private void handleDelete(HttpServletRequest req, HttpServletResponse resp) throws IOException, SQLException { service.remove(Integer.parseInt(req.getParameter("id"))); resp.sendRedirect(req.getContextPath() + "/products"); } private void handleCreate(HttpServletRequest req, HttpServletResponse resp) throws IOException, SQLException { service.create(buildFromRequest(req, 0)); resp.sendRedirect(req.getContextPath() + "/products"); } private void handleUpdate(HttpServletRequest req, HttpServletResponse resp) throws IOException, SQLException { int id = Integer.parseInt(req.getParameter("id")); service.edit(buildFromRequest(req, id)); resp.sendRedirect(req.getContextPath() + "/products"); } private Product buildFromRequest(HttpServletRequest req, int id) { Product p = new Product(); p.setId(id); p.setName(req.getParameter("name")); p.setSku(req.getParameter("sku")); p.setPrice(Double.parseDouble(req.getParameter("price"))); p.setStock(Integer.parseInt(req.getParameter("stock"))); return p; } }

<%@ taglib prefix="c" uri="jakarta.tags.core" %> <html><body> <h1>المنتجات</h1> <a href="${pageContext.request.contextPath}/products?action=new">+ منتج جديد</a> <table> <tr><th>الاسم</th><th>SKU</th><th>السعر</th><th>المخزون</th><th>الإجراءات</th></tr> <c:forEach var="p" items="${products}"> <tr> <td><c:out value="${p.name}"/></td> <td><c:out value="${p.sku}"/></td> <td><c:out value="${p.price}"/></td> <td><c:out value="${p.stock}"/></td> <td> <a href="products?action=edit&amp;id=${p.id}">تعديل</a> <a href="products?action=delete&amp;id=${p.id}" onclick="return confirm('حذف هذا المنتج؟')">حذف</a> </td> </tr> </c:forEach> </table> </body></html>

<%@ taglib prefix="c" uri="jakarta.tags.core" %> <html><body> <h1><c:choose> <c:when test="${product.id == 0}">منتج جديد</c:when> <c:otherwise>تعديل المنتج</c:otherwise> </c:choose></h1> <form method="post" action="${pageContext.request.contextPath}/products"> <input type="hidden" name="action" value="${product.id == 0 ? 'create' : 'update'}"/> <c:if test="${product.id != 0}"> <input type="hidden" name="id" value="${product.id}"/> </c:if> <label>الاسم: <input name="name" value="<c:out value='${product.name}'/>" required/></label><br/> <label>SKU: <input name="sku" value="<c:out value='${product.sku}'/>" required/></label><br/> <label>السعر:<input name="price" type="number" step="0.01" value="${product.price}" required/></label><br/> <label>المخزون:<input name="stock" type="number" value="${product.stock}" required/></label><br/> <button type="submit">حفظ</button> <a href="${pageContext.request.contextPath}/products">إلغاء</a> </form> </body></html>

package com.example.catalogue.db; import com.zaxxer.hikari.HikariConfig; import com.zaxxer.hikari.HikariDataSource; import javax.sql.DataSource; public class DataSourceProvider { private static final HikariDataSource DS; static { HikariConfig cfg = new HikariConfig(); cfg.setJdbcUrl(System.getenv("DB_URL")); // مثال: jdbc:mysql://localhost/catalogue cfg.setUsername(System.getenv("DB_USER")); cfg.setPassword(System.getenv("DB_PASS")); cfg.setMaximumPoolSize(10); DS = new HikariDataSource(cfg); } public static DataSource get() { return DS; } }

CREATE TABLE products ( id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(120) NOT NULL, sku VARCHAR(60) NOT NULL UNIQUE, price DECIMAL(10,2) NOT NULL DEFAULT 0.00, stock INT NOT NULL DEFAULT 0 );