Session & Cookie Login Case January 27,2020

 ## Case: Captcha

1. Case Requirements:
　　1. Access the login page with the code of the login.jsp
2. user to enter a user name, password and a verification code.
　　* If the username and password entered incorrectly, skip the login page Note: user name or password is incorrect
　　* If the code is entered incorrectly, jump login page Tip: Codes error
　　* If all input is correct, then jump to the home page success.jsp, displayed: user name, you are welcome

2. Analysis:

　　

 

 

 

package domain;
/**
 * 用户 实体类
 */
public class User {
        private int id;
        private String username;
        private String password;

        public User() {
        }

        public User(int id, String username, String password) {
            this.id = id;
            this.username = username;
            this.password = password;
        }

        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;
        }

        @Override
        public String toString() {
            return "User{" +
                    "id=" + id +
                    ", username='" + username + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }

}

 

package util;

import com.alibaba.druid.pool.DruidDataSourceFactory;

import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;

/**
 * JDBC工具类 druid
 */
public class JDBCUtils {
    private static DataSource ds;
    static {
        try {
            //1.加载配置文件
            Properties properties = newThe Properties ();
             // use ClassLoader load profile, obtaining input stream of bytes 
            the InputStream resourceAsStream = JDBCUtils. Class .getClassLoader () the getResourceAsStream ( "druid.properties." ); 
            Properties.load (resourceAsStream); 
            // 2. initial connection pool object 
            DS = DruidDataSourceFactory.createDataSource (Properties); 
        } the catch (IOException E) { 
            e.printStackTrace (); 
        } the catch (Exception E) { 
            e.printStackTrace (); 
        } 

    } 
    / ** 
     * Get Connection object 
     * / 
    public  staticThe getConnection Connection () throws SQLException {
         return ds.getConnection (); 
    } 

    / ** 
     * Gets connection pool object 
     * / 
    public  static the DataSource getDataSource () {
         return DS; 
    } 
}

 

Package DAO; 

Import domain.User;
 Import org.springframework.dao.DataAccessException;
 Import org.springframework.jdbc.core.BeanPropertyRowMapper;
 Import org.springframework.jdbc.core.JdbcTemplate;
 Import util.JDBCUtils; 

/ ** 
 * database operations user table class 
 * * / 
public  class UserDao {
     // declare JDBCTemplate object shared 
    Private the JdbcTemplate the jdbcTemplate = new new the JdbcTemplate (JDBCUtils.getDataSource ());
     / ** 
     * Log method 
     * @param loginUser and only the user password 
     * @returnuser returns the user all the information
      * / 
    public the User the Login (the User loginUser) {
         the try { 
            String SQL = "the SELECT * from the WHERE user = username and password =??" ;
             // result is package query the USER 
            the User user = jdbcTemplate. queryForObject (SQL,
                     new new BeanPropertyRowMapper <the User> (the User. class ), 
                    loginUser.getUsername (), loginUser.getPassword ()); 
            return User; 
        } the catch (the DataAccessException E) { 
            e.printStackTrace (); 
            return  null ; 
        } 
    } 
}

 

package web.servlet;

import javax.imageio.ImageIO;
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.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

/**
    验证码 案例
 */
@WebServlet( "/checkCodeServlet")
 Public  class CheckCodeServlet the extends the HttpServlet {
     protected  void the doPost (the HttpServletRequest Request, the HttpServletResponse Response) throws ServletException, IOException {
         // 1. Create an object image stored in memory 
        int width = 100 ;
         int heigth = 50 ; 
        the BufferedImage Image = new new the BufferedImage (width, heigth, BufferedImage.TYPE_INT_RGB);
         // 2. beautify the picture
             // 2.1 fill the background color 
        Graphics Graphics = image.getGraphics (); // Paintbrush Object
        graphics.setColor (Color.PINK); // Set brush color 
        graphics.fillRect (0,0, width, heigth); // filled rectangle
             // 2.2 Videos border 
        graphics.setColor (Color.BLUE); 
        as graphics.drawRect ( 0 , 0,. 1-width,-heigth. 1); // because the brush has to be reduced so that a 1px
             @ 2.3 fill codes 
        String STR = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" ; 

        the StringBuilder img_str = new new the StringBuilder (); // for storing codes information of 
        the Random Random = new new the Random ();
         for ( int i = 1; i <=4 ; i++) {
            int index = random.nextInt(str.length());
            graphics.drawString(str.charAt(index)+"",width/5*i,heigth/2);
            img_str.append(str.charAt(index));
        }
        HttpSession session = request.getSession();
        session.setAttribute("checkCode_session",img_str.toString());
        //2.4画干扰线
        graphics.setColor(Color.green);
        for (int i = 0; i <10 ; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(heigth);
            int y2 = random.nextInt(heigth);
            graphics.drawLine(x1,y1,x2,y2);
        }
        //3.将图片输出至页面展示
        ImageIO.write(image,"jpg",response.getOutputStream());

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

 

package web.servlet;

import dao.UserDao;
import domain.User;
import org.apache.commons.beanutils.BeanUtils;

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.lang.reflect.InvocationTargetException;
import java.util.Map;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.设置编码
        request.setCharacterEncoding("utf-8");
        //2.获取请求参数
        String login_username = request.getParameter("username");
        String login_password = request.getParameter("password");
        String login_checkCode = request.getParameter("checkCode");
        //3.获取验证码
        = Session the HttpSession Request.getSession (); 
        String checkCode_session = (String) session.getAttribute ( "checkCode_session" );
         // delete the session codes stored in 
        session.removeAttribute ( "checkCode_session" ); 

        // 4. Analyzing whether codes case-insensitive comparison correct 
        iF (login_checkCode =! null && checkCode_session.equalsIgnoreCase (login_checkCode)) {
             // 5. the code is correct username and password are correct Analyzing 
            the User loginUser = new new the User (); 
            loginUser.setUsername (login_username); 
            loginUser. the setPassword (login_password); 
            UserDao userDao =new new UserDao (); 
            the User the User = userDao.login (loginUser);
             IF (the User == null ) {
                 // Login failed
                 // stored message to the Request 
                request.setAttribute ( "login_error", "user name or password is incorrect" ) ;
                 // forwarded to the login page 
                request.getRequestDispatcher ( "/ the login.jsp" ) .forward (Request, the Response); 
            } the else {
                 // successful login
                 // store information, because the user information user information can span many pages, so use session without using the Request 
                session.setAttribute ( "the User",user.getUsername());
                //重定向到success.jsp
                response.sendRedirect(request.getContextPath()+"/success.jsp");
            }
        }else{
            request.setAttribute("cc_error","验证码错误");
            //验证码错误
            request.getRequestDispatcher("login.jsp").forward(request,response);
        }

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}

 

<% @ Page contentType = "text / HTML; charset = UTF-8" Language = "the Java"%> 
<HTML> 
<head> 
    <title> Log Case </ title> 
    ! <- 
    Analysis: 
        Click on the image, the need for a
             1 . hyperlinks and pictures to bind the click event
             2 . reset the image src attribute value
     -> 
    <Script> 
        the window.onload = function () { 
            document.getElementById ( "img") onclick =. function ( ) {
                 the this .src = "? $ {} pageContext.request.contextPath / checkCodeServlet" + new new a Date () the getTime ();. 
            } 
        }
     </ Script> 
</ head>
<body>
        <form action="${pageContext.request.contextPath}/loginServlet" method="post">
            <table>
                <tr>
                    <td>用户名</td>
                    <td><input type="text" placeholder="请输入用户名" name="username"></tr></td>
                <tr>
                    <td>密码</td>
                    <td><input type="text" placeholder="请输入用户密码" name="password"></td>
                </tr>
                <tr >
                    <td>验证码</td>
                    <td><input type="text"placeholder = "Please enter PIN" name = "checkCode"> </ TD> 
                <TR>
                </ TR>
                    <td colspan="2"><img id="img" src="${pageContext.request.contextPath}/checkCodeServlet"></td>
                </tr>
                <tr>
                    <td colspan="2"><input type="submit" value="登录"></td>
                </tr>
            </table>
        </form>
        ${requestScope.cc_error}
        ${requestScope.login_error}

</body>
</html>

 

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录成功页面</title>
</head>
<body>
    <%
        HttpSession session1 = request.getSession();
        String user = (String) session1.getAttribute("user");
        out.print(user+"欢迎登录");
    %>
</body>
</html>