使用者登入驗證
1.案例需求：
1.通路帶有驗證碼的登入頁面login.jsp
2.使用者輸入使用者名，密碼以及驗證碼
* 如果使用者名和密碼輸入有誤，跳轉登入頁面，提示：使用者名或密碼錯誤
* 如果驗證碼輸入有誤，跳轉登入頁面，提示：驗證碼錯誤
* 如果全部輸入正确，則跳轉到首頁success.jsp，顯示：使用者名，歡迎您
代碼如下
login.jsp
login
window.οnlοad=function () {
document.getElementById("img").οnclick=function () {
this.src="/08__war_exploded/CheckCodeServlet?time="+new Date().getTime();
}
}
div{
color:red;
}
| 使用者名 |
| 密碼 |
| 驗證碼 |
 |
success.jsp
Title
,歡迎您
session
package cn.itcast.servlet;
import cn.itcast.entity.UserDao;
import cn.itcast.respository.UserRespository;
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;
@WebServlet("/loginServlet")
public class loginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//設定request編碼
request.setCharacterEncoding("utf-8");
//擷取參數
String username=request.getParameter("username");
String password=request.getParameter("password");
String checkCode=request.getParameter("checkCode");
//封裝對象
UserDao loginUser=new UserDao();
loginUser.setUsername(username);
loginUser.setPassword(password);
// 執行個體化一個StudentResponsitory對象
UserRespository userd = new UserRespository();
String usernameone=userd.getList().getUsername();
String passwordone=userd.getList().getPassword();
// //判斷userd
// if(userd==null){
// //登入失敗
// request.getRequestDispatcher("/failServlet").forward(request,response);
// }else{
// //登入成功
// //存儲資料
// request.setAttribute("userd",userd);
// //轉發
// request.getRequestDispatcher("/successServlet").forward(request,response);
// }
// System.out.println("--------------1---------------");
// System.out.println(usernameone);
// System.out.println("---------------2--------------");
// System.out.println(passwordone);
// System.out.println("---------------3--------------");
// System.out.println(userd.QueryAll());
// System.out.println("---------------4--------------");
// System.out.println(userd.getList().get(0).getUsername());
// System.out.println("---------------5--------------");
// System.out.println(userd.getList().get(0).getPassword());
// System.out.println("---------------6--------------");
//擷取checkCode_session
HttpSession session=request.getSession();
String checkCode_session=(String) session.getAttribute("checkCode_session");
//删除session中存儲的驗證碼
session.removeAttribute("checkCode_session");
//先判斷驗證碼是否正确
if(checkCode_session!=null && checkCode_session.equalsIgnoreCase(checkCode)){
//忽略大小寫比較
//驗證碼正确
//判斷使用者名和密碼是否一緻
if(usernameone.equals(username)&&passwordone.equals(password)){
//需要調用資料庫來進行操作
//登入成功
//存儲資訊，使用者資訊
session.setAttribute("user",username);
//重定向到success.jsp
response.sendRedirect(request.getContextPath()+"/success.jsp");
}else{
//登入失敗
//存儲提示資訊到request
request.setAttribute("login_error","使用者名或者密碼錯誤");
//轉發到登入頁面
request.getRequestDispatcher("/login.jsp").forward(request,response);
}
}else{
//驗證碼不一緻
//存儲提示資訊到request
request.setAttribute("cc_error","驗證碼錯誤");
//轉發到登入頁面
request.getRequestDispatcher("/login.jsp").forward(request,response);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}
驗證碼設計
package cn.itcast.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 java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
@WebServlet("/CheckCodeServlet")
public class CheckCodeServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int width = 100;
int height = 50;
//建立一對象，在記憶體中圖檔(驗證碼圖檔對象)
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
//美化圖檔
//2.1.填充背景色
Graphics g = image.getGraphics();//畫筆對象
g.setColor(Color.pink);//設定畫筆顔色
g.fillRect(0, 0, width, height);
//2.2.畫邊框
g.setColor(Color.BLUE);
g.drawRect(0, 0, width - 1, height - 1);
String str = "ABCDEFGHIJKLMNOPQRSTOVWXYZabcdefghijklmnopqrstovwxyz";
//生成随機角标
Random ran = new Random();
StringBuilder sb=new StringBuilder();
for (int i = 1; i <= 4; i++) {
int index = ran.nextInt(str.length());
//擷取字元
char ch = str.charAt(index);//随機字元
sb.append(ch);
g.drawString(ch + "", width / 5 * i, height / 2);
//2.3.寫驗證碼
}
String checkCode_session=sb.toString();
//将驗證碼存入session
request.getSession().setAttribute("checkCode_session",checkCode_session);
//2.4畫幹擾線
g.setColor(Color.GREEN);
for (int i = 0; i <= 4; i++) {
int x1 = ran.nextInt(width);
int x2 = ran.nextInt(width);
int y1 = ran.nextInt(height);
int y2 = ran.nextInt(height);
g.drawLine(x1, x1, x2, y2);
}
//将圖檔輸出到頁面顯示
ImageIO.write(image, "jpg", response.getOutputStream());
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
}