Jsp学生信息管理系统登录验证全代码

jsp登录界面 Login.jsp <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

学生信息信息

管理系统

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用户名:

密    码:

2.java代码 User.Java 定义的属性和数据库中的字段相对应 package com.softeem.dt; public class User { private int id; private String username; private String password; private String xh; private String college; public int getId(){ return id; } public void setId(int id){ this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getXh() { return xh; } public void setXh(String xh) { this.xh = xh; } public String getCollege() { return college; } public void setCollege(String college) { this.college = college; } } UserDAO.java 操作数据库tb_user,验证用户登录 package com.softeem.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import com.softeem.db.DBManager; import com.softeem.dt.User; public class UserDAO { /** * 验证用户登录 * @return */ public boolean checkDenglu(User user) { boolean flag = false; // 获得数据库连接 Connection conn = DBManager.getConnection(); // 用select * from查询数据库中的所有字段 String sql = "select count(*) from tb_user where username=? and password=?"; try { PreparedStatement pst = conn.prepareStatement(sql); pst.setString(1, user.getUsername()); pst.setString(2, user.getPassword()); // 执行查询语句,拿到结果集 ResultSet rs = pst.executeQuery(); while (rs.next()) { int count = rs.getInt(1); //用count和0比较,若大于0示该用户存在,否则不存在 if(count > 0){ flag = true; } } } catch (SQLException e) { e.printStackTrace(); } return flag; } } 3.LoginServlet,点击登录跳转到服务器端 package com.softeem.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.softeem.dao.UserDAO; import com.softeem.dto.User; /** * Servlet implementation class LoginServlet */ public class LoginServlet extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public LoginServlet() { super(); } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { super.doGet(request, response); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //获取表单数据 //处理乱码 request.setCharacterEncoding("utf-8"); String username = request.getParameter("username"); String password = request.getParameter("password"); //封装到user对象中 User user = new User(); user.setUsername(username); user.setPassword(password); //调用dao的checkLogin方法 UserDAO dao = new UserDAO(); boolean flag = dao.checkLogin(user); String message = null; String path = null; if(flag){ message = "登录成功"; path="success.jsp"; request.getSession().setAttribute("user", user); }else{ message ="对不起密码错误,请重新输入!"; path="fail.jsp"; } //response返回message response.setCharacterEncoding("utf-8"); response.getWriter().write(message);*/ //属于服务器跳转,浏览器地址栏没有发生改变 request.getRequestDispatcher(path).forward(request,response); } }