@WebServlet("/hello")
public class HelloWorldServlet extends HttpServlet {
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html><body>");
out.println("<h1>Hello, World!</h1>");
out.println("</body></html>");
}
}
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
id="WebApp_ID" version="4.0">
<display-name>MyJakartaEEApp</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
@Entity
public class Customer {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String email;
// getters and setters
}
@Stateless
public class CustomerService {
@PersistenceContext
private EntityManager em;
public void createCustomer(Customer customer) {
em.persist(customer);
}
public List<Customer> getAllCustomers() {
TypedQuery<Customer> query = em.createQuery("SELECT c FROM Customer c", Customer.class);
return query.getResultList();
}
}
