jsp调用servlet验证码问题
我用serlvet做了一个动态生成验证码的类，请问在jsp表单中怎么调用？
网上找到的
显示验证码的html页面login.html代码如下：
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>login.html</title>
<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">
<!--<link rel="stylesheet" type="text/css" href="./styles.css">-->
</head>
<body>
<center>
<form action="login" method="post">
验证码：<input type="text" name="random"><img src="imgcode">
<br>
<br>
<input type="submit" value="提交">
</form>
</center>
</body>
</html>
动态生成验证码的servlet类RandomCodeServlet.java代码如下：
package iss
import java.awt.Color
import java.awt.Font
import java.awt.Graphics2D
import java.awt.image.BufferedImage
import java.util.Random
import javax.servlet.ServletException
import javax.servlet.ServletOutputStream
import javax.servlet.http.HttpServlet
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse
import javax.servlet.http.HttpSession
import javax.imageio.*
public class RandomCodeServlet extends HttpServlet ...{
/** *//**
* Constructor of the object.
*/
public RandomCodeServlet() ...{
super()
}
//验证码图片的宽度
private int width=60
//验证码图片的高度
private int height=20
protected void service(HttpServletRequest request,HttpServletResponse response)
throws ServletException,{
BufferedImage buffImg=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB)
Graphics2D g=buffImg.createGraphics()
//创建一个随机数生成器
Random random=new Random()
g.setColor(Color.WHITE)
g.fillRect(0, 0, width, height)
//创建字体，字体的大小应该根据图片的高度来定
Font font=new Font("Times New Roman",Font.PLAIN,18)
//设置字体
g.setFont(font)
//画边框
g.setColor(Color.BLACK)
g.drawRect(0, 0, width-1, height-1)
//随机产生160条干扰线
g.setColor(Color.GRAY)
for(int i=0i<160i++)...{
int x=random.nextInt(width)
int y=random.nextInt(height)
int x1=random.nextInt(12)
int y1=random.nextInt(12)
g.drawLine(x, y, x+x1, y+y1)
}
//randomCode用于保存随机产生的验证码
StringBuffer randomCode=new StringBuffer()
int red=0,green=0,blue=0
//随机产生4位数字的验证码
for(int i=0i<4i++)...{
//得到随机产生的验证码数字
String strRand=String.valueOf(random.nextInt(10))
//产生随机的颜色分量来构造颜色值
red=random.nextInt(110)
green=random.nextInt(50)
blue=random.nextInt(50)
//用随机产生的颜色将验证码绘制到图像中
g.setColor(new Color(red,green,blue))
g.drawString(strRand, 13*i+6, 16)
randomCode.append(strRand)
}
//将四位数字的验证码保存到session中
HttpSession session=request.getSession()
session.setAttribute("randomCode", randomCode.toString())
//禁止图像缓存
response.setHeader("Pragma", "no-cache")
response.setHeader("Cache-Control", "no-cache")
response.setDateHeader("Expires", 0)
response.setContentType("image/jpeg")
//将图像输出到servlet输出流中
ServletOutputStream sos=response.getOutputStream()
ImageIO.write(buffImg, "jpeg", sos)
sos.close()
}
}
判断验证码是否匹配的LoginServlet.java代码如下：
package iss
import
import
import javax.servlet.ServletException
import javax.servlet.http.HttpServlet
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse
import javax.servlet.http.HttpSession
public class LoginServlet extends HttpServlet ...{
/** *//**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException ...{
HttpSession session=request.getSession()
String randomCode=(String)session.getAttribute("randomCode")
if(null==randomCode)...{
response.sendRedirect("login.html")
return
}
String reqRandom=request.getParameter("random")
response.setCharacterEncoding("gbk")
response.setContentType("text/htmlcharset=gb2312")
PrintWriter out = response.getWriter()
if(randomCode.equals(reqRandom))...{
out.println("验证码匹配！")
}else...{
out.println("验证码不匹配！")
}
out.close()
}
}
web.xml如下：
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
xmlns="http://java.
xmlns:xsi="http://www.
xsi:schemaLocation="http://java.
http://java.
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>RandomCodeServlet</servlet-name>
<servlet-class>iss.RandomCodeServlet</servlet-class>
</servlet>
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>iss.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RandomCodeServlet</servlet-name>
<url-pattern>/imgcode</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>
