IDEA激活码
1.案例需求：
1.访问带有验证码的登录页面：login.jsp
2.用户输入用户名，密码以及验证码
如果用户名和密码输入有误，跳转到登录页面，提示：用户名和密码错误
如果验证码输入有误，跳转登录页面，提示：验证码错误
如果全部输入正确，则跳转到主页success.jsp，提示：用户名，欢迎您
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
<script type="text/javascript">
onload=function(){
document.getElementById("img").onclick=function(){
this.src="/19-Cookie&Session/CheckCodeServlet?time="+new Date().getTime();
}
}
</script>
</head>
<body>
<form action="/19-Cookie&Session/LoginServlet" method="post">
<table>
<tr>
<td>用户名</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密码</td>
<td><input type="text" name="password"></td>
</tr>
<tr>
<td>验证码</td>
<td><input type="text" name="checkCode"></td>
</tr>
<tr>
<td colspan="2"><img id="img" src="/19-Cookie&Session/CheckCodeServlet"></td>
</tr>
<tr>
<td colspan="2"><input type="submit" value="登录"></td>
</tr>
</table>
</form>
<div><%= request.getAttribute("cc_error")==null?"":request.getAttribute("cc_error")%></div>
<div><%=request.getAttribute("login_error")==null?"":request.getAttribute("login_error")%></div>
</body>
</html>
package 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 CheckCodeSevlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int width = 100;
int height = 50;
//创建一个对象，在内存中代表图片
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
//美化图片
//填充背景色
Graphics g = image.getGraphics();//画笔对象
//设置画笔的颜色
g.setColor(Color.pink);
g.fillRect(0,0,width,height);
//画边框
g.setColor(Color.BLUE);
g.drawRect(0,0,width-1,height-1);
String str ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
//生成随机角标
Random ran = new Random();
StringBuilder sb = new StringBuilder();
//写验证码
for(int i=1;i<=4;i++){
int index = ran.nextInt(str.length());
//获取字符
char ch = str.charAt(index);
sb.append(ch);
g.drawString(ch+"",width/5*i,25);
}
String checkCode_session = sb.toString();
//将验证码存入session
request.getSession().setAttribute("checkCode_session",checkCode_session);
//画干扰线
for(int i=0;i<5;i++){
//随机生成四个点
int x1 = ran.nextInt(width);
int y1 = ran.nextInt(height);
int x2 = ran.nextInt(width);
int y2 = ran.nextInt(height);
g.setColor(Color.GREEN);
g.drawLine(x1,y1,x2,y2);
}
//将图片输出到页面
ImageIO.write(image,"jpg",response.getOutputStream());
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request,response);
}
}
package Servlet;
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 {
//设置编码
request.setCharacterEncoding("utf-8");
//获取参数
String username = request.getParameter("username");
String password = request.getParameter("password");
String checkCode = request.getParameter("checkCode");
//先获取生成的验证码
HttpSession session = request.getSession();
String checkCode_session = (String) session.getAttribute("checkCode_session");
//删除session中存储的验证码
session.removeAttribute("checkCode_session");
//判断验证码是否正确
if (checkCode_session.equalsIgnoreCase(checkCode)) {
//判断用户名和密码
//验证码正确
//判断用户名和密码是否一致
if ("zhangsan".equals(username) && "123".equals(password)) {
//查询数据库
//登录成功
//存储用户信息
session.setAttribute("user", "username");
//重定向到success.jsp
response.sendRedirect(request.getContextPath() + "/success.jsp");
} else {
//登录失败
//存储信息到request
request.setAttribute("login_error", "用户名或者密码错误");
//转发到登录页面
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
} else {
//验证码不一致
//存储提示信息到request
request.setAttribute("cc_error", "验证码错误");
//转发到登录页面
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="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1><%= request.getSession().getAttribute("user")%>欢迎您！</h1>
</body>
</html>
