Dies ist der Code für meinen Controller < /p>
package mvcController;
import mvcModel.*;
import jakarta.ejb.EJB;
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 mvcModel.SubjectService;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import entities.Subject;
/**
* Servlet implementation class Controller
*/
public class Controller extends HttpServlet {
private static final long serialVersionUID = 1L;
@EJB
private SubjectService subjectService;
/**
* @see HttpServlet#HttpServlet()
*/
public Controller() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.getWriter().append("Served at: ").append(request.getContextPath());
List subjects = new ArrayList();
subjects = subjectService.getAllSubjects();
for(Subject sub : subjects)
response.getWriter().append(sub.getSubjectTitle()+"\n");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}
< /code>
Und dies ist meine perisstence.xml -Datei < /p>
java:/MysqlXADS
< /code>
Hinweise zu berücksichtigen: < /p>
- Jede Entität hat die @Entity -Annotation < /li>
MySQL -Datenbank erstellt und verfügt über die 3 Tabellen und Daten (verifiziert mit Select *)