Java-JSP頁面實現簡單登入退出（僅供參考）
阿新 • • 發佈：2020-12-23
1、JSP頁面程式碼
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" type="text/css" href="./css/login/normalize.css" /> <link rel="stylesheet" type="text/css" href="./css/login/demo.css" /> <link rel="stylesheet" type="text/css" href="./css/login/component.css" /> <title>登入</title> </head> <body> <body> <div class="container demo-1"> <div class="content"> <div id="large-header" class="large-header"> <canvas id="demo-canvas"></canvas> <div class="logo_box"> <h3>登入</h3> <form action="${pageContext.request.contextPath }/login/loginyy" name="f" method="post"> <div class="input_outer"> <span class="u_user"></span> <input id="username" name="username" value="" class="text" style="color: #FFFFFF !important" type="text" placeholder="請輸入賬戶"> </div> <div class="input_outer"> <span class="us_uer"></span> <input id="password" name="password" value="" class="text" style="color: #FFFFFF !important; position:absolute; z-index:100;" type="password" placeholder="請輸入密碼"> </div> <div class="mb2"> <!-- <a class="act-but submit" href="${pageContext.request.contextPath }/login/loginyy" style="color: #FFFFFF"> --> <input class="text" type="submit" value="登入" style="color: #FFFFFF"> </a> </div> </form> </div> </div> </div> </div><!-- /container --> <script src="./js/login/TweenLite.min.js"></script> <script src="./js/login/EasePack.min.js"></script> <script src="./js/login/rAF.js"></script> <script src="./js/login/demo-1.js"></script> <div style="text-align:center;"> </div> </body> </html>
2、建立登入使用者User實體類
package com.chao.entity; public class User { private String username; private String password; public String getUsername() { return this.username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return this.password; } public void setPassword(String password) { this.password = password; } }
3、mysql資料庫連線池
package com.chao.utils; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBUtil { private String dbUrl = "jdbc:mysql://資料庫ip地址:3306/login"; private String dbUserName = "資料庫使用者名稱"; private String dbPassword = "資料庫登入密碼"; private String jdbcName = "com.mysql.cj.jdbc.Driver"; public Connection getCon() throws ClassNotFoundException, SQLException { Class.forName(this.jdbcName); Connection con = DriverManager.getConnection(this.dbUrl, this.dbUserName, this.dbPassword); return con; } public void closeCon(Connection con) throws SQLException { if (con != null) con.close(); } }
4、登入程式碼實現
package com.chao.controller; import com.chao.entity.User; import com.chao.utils.DBUtil; import com.chao.utils.StringUtil; import java.io.IOException; import java.io.PrintWriter; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; @Controller @RequestMapping({ "login" }) public class LoginController { @RequestMapping public String toLoginIndex(Model model) { return "login"; } @RequestMapping({ "loginyy" }) public void toLogin(HttpServletRequest request, HttpServletResponse response) { User user = new User(); String username = request.getParameter("username"); String password = request.getParameter("password"); user.setUsername(username); user.setPassword(password); System.out.println("----------------" + username + "--" + password + "---------------"); if ((StringUtil.isEmpty(password)) || (StringUtil.isEmpty(username))) { HttpSession session = request.getSession(); session.setAttribute("error", "不能為空"); try { response.sendRedirect(request.getContextPath() + "/login"); } catch (IOException e) { e.printStackTrace(); } System.out.println("---------kong----------"); return; } DBUtil db = new DBUtil(); String sql = "select username from users where username='" + user.getUsername() + "'"; String sql1 = "select password from users where password='" + user.getPassword() + "'"; try { Statement stmt = db.getCon().createStatement(); Statement stmt1 = db.getCon().createStatement(); ResultSet rs = stmt.executeQuery(sql); ResultSet rs1 = stmt1.executeQuery(sql1); if ((rs.next()) && (rs1.next())) { HttpSession session = request.getSession(); session.setAttribute("currentUser", "登陸成功"); response.sendRedirect("/file"); } else { System.out.println("-------使用者名稱或密碼錯誤-----"); HttpSession session = request.getSession(); session.setAttribute("error", "錯誤"); session.setAttribute("username", username); session.setAttribute("password", password); response.setCharacterEncoding("GB2312"); PrintWriter out = response.getWriter(); out.print("<script>alert('使用者名稱或密碼錯誤,請重新輸入!'); window.location='/login' </script>"); } } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }
5、JSP頁面直接跳轉攔截驗證
<%
if(null==session.getAttribute("currentUser")){
System.out.print("ddd");
response.sendRedirect("/login");
return;
}else{
System.out.print("yyy");
}
%>