computer-web/src/main/java/example/controller/ComputerServlet.java

package example.controller;

import example.model.Computer;
import example.service.IComputerService;
import example.service.impl.ComputerServiceImpl;

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 java.io.IOException;
import java.sql.SQLException;
import java.util.List;

@WebServlet(urlPatterns = {"/computerList","/deleteComputer"})
public class ComputerServlet extends HttpServlet {

    IComputerService computerService = new ComputerServiceImpl();

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String path = req.getServletPath();
        switch (path) {
            case "/computerList":
                try {
                    listServlet(req, resp);
                } catch (SQLException e) {
                    throw new RuntimeException(e);
                }
                break;
            case "/deleteComputer":
                deleteComputer(req, resp);
                break;
        }
    }

    private void deleteComputer(HttpServletRequest req, HttpServletResponse resp) {
        String id = req.getParameter("id");
        try {
            computerService.deleteComputer(id);
            resp.sendRedirect("/computerList");
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private void listServlet(HttpServletRequest req, HttpServletResponse resp) throws SQLException, ServletException, IOException {
        List<Computer> computers= computerService.listComputer();
        req.setAttribute("computers", computers);
        req.getRequestDispatcher("computerList.jsp").forward(req, resp);
    }
}