Java Web 实验项目 初步实现maven和idea的整合

package com.controller; import com.dao.UserDao; import com.dao.UserDaoImpl; import com.service.UserServiceImpl; import javax.servlet.http.HttpServlet; import com.entity.User; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.sql.SQLException; import java.util.List; @WebServlet("/user") public class UserController extends HttpServlet { UserDao userDao = new UserDaoImpl(); UserServiceImpl userService = new UserServiceImpl(userDao); @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String action = request.getParameter("action"); try{ if("query".equals(action)){ queryUsers(request, response); } else if ("add".equals(action)) { addUser(request, response); } else if ("delete".equals(action)) { deleteUser(request, response); } else if ("update".equals(action)) { updateUser(request, response); } } catch (SQLException e) { e.printStackTrace(); response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,"Database error"); } } @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { this.doPost(req, resp); } private void addUser(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException, ServletException { int id= Integer.parseInt(request.getParameter("id")); String username=request.getParameter("username"); String pwd=request.getParameter("pwd"); userService.addUser(id,username,pwd); request.getRequestDispatcher("/user.jsp").forward(request, response); response.sendRedirect("user?action=query"); } private void queryUsers(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException, SQLException { List users = userService.getAllUsers(); request.setAttribute("users", users); request.getRequestDispatcher("/user.jsp").forward(request, response); } private void deleteUser(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException, ServletException { String id = request.getParameter("id"); userService.deleteUser(id); request.getRequestDispatcher("/user.jsp").forward(request, response); response.sendRedirect("user?action=query"); } private void updateUser(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException, ServletException { int id = Integer.parseInt(request.getParameter("id")); String username = request.getParameter("username"); String pwd = request.getParameter("pwd"); userService.updateUser(id, username, pwd); request.getRequestDispatcher("/user.jsp").forward(request, response); response.sendRedirect("user?action=query"); } }