source: source/MovieZilla-master/src/main/java/com/example/demo/servlet/LoginServlet.java@ fc7ec52

package com.example.demo.servlet;

import com.example.demo.exceptions.InvalidArgumentsException;
import com.example.demo.exceptions.InvalidUserCredentialsException;
import com.example.demo.model.User;
import com.example.demo.service.AuthService;
import org.thymeleaf.context.WebContext;
import org.thymeleaf.spring5.SpringTemplateEngine;

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.util.Optional;

@WebServlet(name="LoginServlet", urlPatterns = "/servlet/login")
public class LoginServlet extends HttpServlet {

    private final SpringTemplateEngine springTemplateEngine;
    private final AuthService authService;

    public LoginServlet(SpringTemplateEngine springTemplateEngine, AuthService authService) {
        this.springTemplateEngine = springTemplateEngine;
        this.authService = authService;
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        WebContext context = new WebContext(req,resp,req.getServletContext());
        springTemplateEngine.process("login.html",context,resp.getWriter());
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");

        Optional<User> user = null;
        try {
            user = authService.login(username,password);

        } catch (InvalidUserCredentialsException | InvalidArgumentsException ex ) {
            WebContext context = new WebContext(req,resp,req.getServletContext());
            context.setVariable("hasError",true);
            context.setVariable("error",ex.getMessage());
            springTemplateEngine.process("login.html",context,resp.getWriter());
            return;
        }
        req.getSession().setAttribute("user",user);
        resp.sendRedirect("/movies");
    }
}