lsepidemicsituationsystem7/src/com/controller/alluse/LoginServlet.java

package com.controller.alluse;

import com.alibaba.druid.util.JdbcUtils;
import com.dao.SchoAdminDao;
import com.dao.StuDao;
import com.dao.TeaDao;

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 javax.servlet.http.HttpSession;
import java.io.IOException;
import java.sql.ResultSet;

/**
 * 处理用户登录请求的Servlet
 * 根据用户选择的身份(学生/教师/管理员)进行不同的验证逻辑
 */
@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        // 设置请求和响应的字符编码，防止中文乱码
        req.setCharacterEncoding("utf-8");
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("text/html;charset=utf-8");

        // 从请求参数中获取用户输入的用户名、密码和身份
        String userName =  req.getParameter("userName");
        String psw =  req.getParameter("psw");
        String identity =  req.getParameter("identity1");
        // 打印日志用于调试
        System.out.println(userName);
        System.out.println(psw);
        System.out.println(identity);

        // 根据用户选择的身份进行不同的验证逻辑
        if (identity.equals("学生")){//学生身份
            boolean flag = false; // 标记是否验证成功
            String sql = "select * from student where sname = ? and spsw = ?"; // SQL查询语句
            Object[] objects = {userName, psw}; // SQL查询参数
            ResultSet resultSet = StuDao.login(sql, objects); // 执行数据库查询
            String sno = null; // 学生学号
            try {
                if (resultSet.next()){ // 如果查询结果不为空
                    flag = true; // 验证成功
                    sno = resultSet.getString("sno"); // 获取学生学号
                }
            } catch (Exception e) {
                e.printStackTrace(); // 打印异常堆栈信息
            }finally {
                JdbcUtils.close(resultSet); // 关闭结果集，释放资源
            }
            if (flag){ // 验证成功
                System.out.println("登录成功!");
                // 创建会话，存储用户信息
                HttpSession session = req.getSession();
                session.setAttribute("userName", userName); // 存储用户名
                session.setAttribute("sno", sno); // 存储学号
                System.out.println(sno);

                // 设置跳转信息并转发到提示页面
                req.setAttribute("httpUrl","/view/stu/stumainview.jsp");
                req.setAttribute("info", "登录成功!即将跳转至后台首页!");
                req.setAttribute("title","登录成功");
                req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
//                resp.sendRedirect(req.getContextPath() + "/view/stu/stumainview.jsp");
            }else { // 验证失败
                System.out.println("用户名或密码错误!请重新登录!");
                // 设置错误信息并转发到提示页面
                req.setAttribute("httpUrl","/view/login/login.jsp");
                req.setAttribute("info", "登录失败!用户名或密码错误!即将跳转至登录页面!");
                req.setAttribute("title","登录失败");
                req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
            }
        }else if (identity.equals("教师")){//教师身份
            boolean flag = false;
            String sql = "select * from teacher where tname = ? and tpsw = ?";
            Object[] objects = {userName, psw};
            ResultSet resultSet = TeaDao.login(sql, objects);
            String tno = null;
            try {
                if (resultSet.next()){
                    flag = true;
                    tno = resultSet.getString("tno");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                JdbcUtils.close(resultSet);
            }
            if (flag){
                System.out.println("登录成功!");
                // 创建会话，存储用户信息
                HttpSession session = req.getSession();
                session.setAttribute("userName", userName);
                session.setAttribute("tno", tno);
                System.out.println(tno);

                // 设置跳转信息并转发到提示页面
                req.setAttribute("httpUrl","/view/tea/teamainview.jsp");
                req.setAttribute("info", "登录成功!即将跳转至后台首页!");
                req.setAttribute("title","登录成功");
                req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
//                resp.sendRedirect(req.getContextPath() + "/view/guide/mainview_guide.jsp");
            }else {
                System.out.println("用户名或密码错误!请重新登录!");
                // 设置错误信息并转发到提示页面
                req.setAttribute("httpUrl","/view/login/login.jsp");
                req.setAttribute("info", "登录失败!用户名或密码错误!即将跳转至登录页面!");
                req.setAttribute("title","登录失败");
                req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
            }
        }else {//如果是管理员
            boolean flag = false;
            String sql = "select * from admin where adname = ? and adpsw = ? and belong = ?";
            Object[] objects = {userName, psw, identity};
            ResultSet resultSet = SchoAdminDao.login(sql, objects);
            try {
                if (resultSet.next()){
                    flag = true;
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                JdbcUtils.close(resultSet);
            }

            if (flag){ // 管理员验证成功

                if (identity.equals("学校")){//学校管理员
                    System.out.println("登录成功!");
                    HttpSession session = req.getSession();
                    session.setAttribute("belong", identity); // 存储管理员所属单位
                    System.out.println(identity);

                    // 设置跳转信息并转发到提示页面
                    req.setAttribute("httpUrl","/view/schoadmin/schomainview.jsp");
                    req.setAttribute("info", "登录成功!即将跳转至后台首页!");
                    req.setAttribute("title","登录成功");
                    req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
                }else {//二级学院管理员
                    System.out.println("登录成功!");
                    // 创建会话，存储用户信息
                    HttpSession session = req.getSession();
                    session.setAttribute("belong", identity);
                    System.out.println(identity);

                    // 设置跳转信息并转发到提示页面
                    req.setAttribute("httpUrl","/view/deptadmin/deptmainview.jsp");
                    req.setAttribute("info", "登录成功!即将跳转至后台首页!");
                    req.setAttribute("title","登录成功");
                    req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
//                resp.sendRedirect(req.getContextPath() + "/view/guide/mainview_guide.jsp");
                }

            }else {
                System.out.println("用户名或密码错误!请重新登录!");
                // 设置错误信息并转发到提示页面
                req.setAttribute("httpUrl","/view/login/login.jsp");
                req.setAttribute("info", "登录失败!用户名或密码错误!即将跳转至登录页面!");
                req.setAttribute("title","登录失败");
                req.getRequestDispatcher("/view/alluse/info.jsp").forward(req, resp);
            }
        }
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp); // 对于POST请求，直接调用doGet方法处理
    }
}