Lista0 - wersja skonfigurowana w aplikacji

PC29-HibernateNaSerwerze/src/main/java/sklep/serwlety/Lista0.java

+package sklep.serwlety;
+
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+import javax.persistence.TypedQuery;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import sklep.model.Product;
+
+// http://localhost:8080/PC29-HibernateNaSerwerze-1.0/Lista0
+@WebServlet("/Lista0")
+public class Lista0 extends HttpServlet {
+	private static final long serialVersionUID = 1L;
+
+	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
+		response.setContentType("text/plain");
+		response.setCharacterEncoding("UTF-8");
+		PrintWriter out = response.getWriter();
+		
+		// W tej wersji obiekty JPA (emf i em) otwieram w sposób ogólny, tak jakby to była zwykła aplikacja.
+		// Nie zakładam, że jestem na serwerze.
+		EntityManagerFactory emf = null;
+		EntityManager em = null;
+		try {
+			emf = Persistence.createEntityManagerFactory("sklep");
+			em = emf.createEntityManager();
+			out.println("Mam połączenie. em = " + em);
+			TypedQuery<Product> query = em.createNamedQuery("Product.findAll", Product.class);
+			List<Product> products = query.getResultList();
+			out.println("Odczytano " + products.size() + " produktów:");
+			for (Product product : products) {
+				out.println(" * " + product.getProductName() + " za " + product.getPrice());
+			}
+			
+		} catch(Exception e) {
+			out.println("Katastrofa " + e);
+			e.printStackTrace(out);
+		} finally {
+			if(em != null) em.close();
+			if(emf != null) emf.close();
+		}
+		
+	}
+
+}