Form.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<title>My JSP ‘Confirm.jsp‘ starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<script type="text/javascript">
function changeImage(img)
{
//document.getElementsByName("img");
//alert("aaaa");
img.src = img.src + "?"+ new Date().getTime();
}
</script>
</head>
<body>
<form name="form" action="/ConfirmDynamicPictureDemo/servlet/ImageCheckServlet" method="post">
验证码： <input type="text" name="info"><image name ="img" src="/ConfirmDynamicPictureDemo/servlet/ImageProduceServlet" alt="图片" onclick="changeImage(this)"/>
<br/>
<input type="submit" value="提交" >
</form>
</body>
</html>
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ImageProduceServlet.java
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
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 ImageProduceServlet extends HttpServlet {
private static final int WIDTH = 120;
private static final int HIGHT = 35;
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
BufferedImage image = new BufferedImage(WIDTH, HIGHT, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
//设置背景颜色
setBackGroud(g);
//设置边框
setBorder(g);
//画干扰线
drawRandomLine(g);
//写随机数,并且存入session
String random = drawRandomNum((Graphics2D)g);
request.getSession().setAttribute("imageCode", random);
//图形写给浏览器
response.setContentType("image/jpeg");
ImageIO.write(image, "jpg", response.getOutputStream());
}
private void setBackGroud(Graphics g)
{
g.setColor(Color.GRAY);
g.fillRect(0, 0, WIDTH, HIGHT);
}
private void setBorder(Graphics g)
{
g.setColor(Color.BLUE);
g.drawRect(1,1,WIDTH-2,HIGHT-2);
}
private void drawRandomLine(Graphics g)
{
g.setColor(Color.GREEN);
for(int i=0;i<5;i++)
{
int x1 = new Random().nextInt(WIDTH);
int y1 = new Random().nextInt(HIGHT);
int x2 = new Random().nextInt(WIDTH);
int y2 = new Random().nextInt(HIGHT);
g.drawLine(x1,y1,x2,y2);
}
}
private String drawRandomNum(Graphics2D g)
{
g.setColor(Color.RED);
g.setFont(new Font("宋体",Font.BOLD,20));
String base = "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
StringBuffer sb = new StringBuffer();
int x =5;
for(int i=0; i<4;i++)
{
int degree = new Random().nextInt()%30; //-30度~30度之间
String ch = base.charAt(new Random().nextInt(base.length()))+"";
sb.append(ch);
g.rotate(degree*Math.PI/180,x,20);
g.drawString(ch, x, 20);
g.rotate(-degree*Math.PI/180,x,20); //保证旋转不是累加的
x+=30;
}
return sb.toString();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request, response);
}
}
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ImageCheckServlet.java
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class ImageCheckServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
request.setCharacterEncoding("UTF-8");
//校验认证码是否有效
String client_code = request.getParameter("info");
String server_code = (String) request.getSession().getAttribute("imageCode");
//没有忽略大小写
if(client_code==null || server_code==null || !server_code.equals(client_code))
{
System.out.println("验证码不正确...");
return;
}
System.out.println("处理客户机请求...");
}
}
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JavaEE动态图片验证
时间： 2024-10-29 19:09:40