//login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
${msg }
<form action="/day11/login" method="post">
<table border="1" width="70%">
<tr>
<td>输入姓名</td>
<td>
<input type="text" name="username" />
</td>
</tr>
<tr>
<td>输入密码</td>
<td>
<input type="password" name="password" />
</td>
</tr>
<tr>
<td>验证码</td>
<td>
<input type="text" name="code" />
<img id="imgId" src="/day11/checkcode">
<a href="#" onclick="run()">看不清，换一张</a>
</td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="登陆"/>
</td>
</tr>
</table>
</form>
</body>
<script type="text/javascript">
// 看不清，换一张，时间戳
function run(){
// 获取图片
var image = document.getElementById("imgId");
image.src = "/day11/checkcode?"+new Date().getTime();
}
</script>
</html>
package CheckCode;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class check extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
final int width=140;
final int height=30;
BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);
Graphics2D g=(Graphics2D)image.getGraphics();
g.setColor(Color.BLACK);
g.fillRect(0, 0, width, height);
g.setColor(Color.BLUE);
g.drawRect(0, 0, width-1, height-1);
String words="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890";
Random random=new Random();
g.setColor(Color.WHITE);
g.setFont(new Font("楷书",Font.PLAIN,18));
int x=20;
int y=20;
StringBuffer sb=new StringBuffer();
for(int i=0;i<5;i++){
int jiaodu=random.nextInt(60)-30;
double hudu=jiaodu*Math.PI/180;
g.rotate(hudu,x,y);
int index=random.nextInt(words.length());
char ch=words.charAt(index);
sb.append(ch);
g.drawString(" "+ch, x, y);
g.rotate(-hudu,x,y);
x+=18;
}
request.getSession().setAttribute("code", sb.toString());
g.setColor(Color.BLUE);
int x1;
int x2;
int y1;
int y2;
for(int i=0;i<4;i++){
x1=random.nextInt(width);
y1=random.nextInt(height);
x2=random.nextInt(width);
y2=random.nextInt(height);
g.drawLine(x1, y1, x2, y2);
}
ImageIO.write(image, "jpg", response.getOutputStream());
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
package CheckCode;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class loginServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.setCharacterEncoding("UTF-8");
String code1=(String)request.getSession().getAttribute("code");
System.out.println(code1);
String code2=request.getParameter("code");
if(code2!=null&&code1.equalsIgnoreCase(code2)){
response.setContentType("text/html;charset=UTF-8");
response.getWriter().write("成功");
}else{
request.setAttribute("msg","验证码错误");
request.getRequestDispatcher("/jsp/login.jsp").forward(request,response);
}
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}