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生成验证码并校验

2017-01-16 22:37 323 查看

jsp-5 生成验证码并校验

依然是以上次的代码为底

index.jsp

新增了验证码一栏

注意他的servlet是新建的ImageServlet

而且中间插了一段JS代码用于刷新验证码

<%@ page language="java" contentType="text/html; charset=UTF-8"
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" "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>
<%
String username="";
String password="";
//取出Cookie
Cookie [] cookie=request.getCookies();
for(int i=0;i<cookie.length;i++){
if(cookie[i].getName().equals("username")){
username=cookie[i].getValue();
}
if(cookie[i].getName().equals("password")){
password=cookie[i].getValue();
}
}

%>
<script type="text/javascript">
//看不清楚重载图片的点击事件
function reloadCode(){
var time=new Date().getTime();
document.getElementById("imagecode").src="<%= request.getContextPath()%>/ImageServlet?d="+time;
}
</script>
<form action="<%=basePath%>/login.do" method="post">
<table border=0 cellpadding=0 cellspacing=0  style="margin:auto;border-collapse:separate; border-spacing:10px;">
<tr align="center">
<td colspan="2">
<label>登录</label>
</td>
</tr>
<tr>
<td>
用户名：
</td>
<td>
<input type="text" name="username" value="<%=username%>">
</td>
</tr>
<tr>
<td>
密码:
</td>
<td>
<input type="password" name="password" value="<%=password%>">
</td>
</tr>
<tr>
<td>
验证码:
</td>
<td>
<input  type="text" name="checkCode"/>
<img alt="验证码" id="imagecode" src="<%= request.getContextPath()%>/ImageServlet"/><a href="javascript:reloadCode();">看不清楚</a><br>
</td>
</tr>
<tr>
<td>
<input type="checkbox" name="ischeck">记住我?
</td>
<td>
&nbsp;&nbsp;<a href="<%=basePath%>/toRegister.do">注册</a>
</td>
</tr>
<tr align="center">
<td>
<input type="submit" value="登录">
</td>
<td>
<input type="reset" value="重置">
</td>
</tr>
</table>
</form>

</body>
</html>

ImageServlet类

还是那一句理论上肯定有人写好包给我们用的

但是我没找到

哈哈哈哈哈哈哈哈哈

package com.javaweb.action;

import java.awt.Color;
import java.awt.Graphics;
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 ImageServlet  extends HttpServlet{
/**
*
*/
private static final long serialVersionUID = 54354321L;

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
// TODO Auto-generated method stub
doPost(req, resp);
}

public void doPost(HttpServletRequest request,HttpServletResponse response) throws IOException{
//这个方法实现验证码的生成
BufferedImage bi=new BufferedImage(68, 22,BufferedImage.TYPE_INT_RGB);//创建图像缓冲区
Graphics g=bi.getGraphics(); //通过缓冲区创建一个画布
Color c=new Color(200,150,255); //创建颜色
/*
* 根据背景画了一个矩形框
*/
g.setColor(c);//为画布添加背景颜色
g.fillRect(0, 0, 68,22); //fillRect:填充指定的矩形

char[] ch="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();//转化为字符型的数组
Random r=new Random();
int len=ch.length;
int index; //index用于存放随机数字
StringBuffer sb=new StringBuffer();
for(int i=0;i<4;i++)
{
index=r.nextInt(len);//产生随机数字
g.setColor(new Color(r.nextInt(88),r.nextInt(188),r.nextInt(255)));  //设置颜色
g.drawString(ch[index]+"",(i*15)+3, 18);//画数字以及数字的位置
sb.append(ch[index]);
}
request.getSession().setAttribute("piccode",sb.toString()); //将数字保留在session中，便于后续的使用
ImageIO.write(bi, "JPG", response.getOutputStream()); //输出图片
}
}

web.xml

不要忘记静态注册新的servlet

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>servlet_sql_mvc_cookie</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<servlet>
<servlet-name>servletSqlMvcCookie</servlet-name>
<servlet-class>com.javaweb.action.ServletSqlMvcCookie</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>servletSqlMvcCookie</servlet-name>
<url-pattern>*.do</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>com.javaweb.action.ImageServlet</servlet-class>
</servlet>

<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/ImageServlet</url-pattern>
</servlet-mapping>
</web-app>

最后只要改改login方法

public void login(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
User user=new User();
String username=req.getParameter("username");
user.setUsername(username);
String password=req.getParameter("password");
user.setPassword(password);

String piccode=(String) req.getSession().getAttribute("piccode");
String checkCode=req.getParameter("checkCode");  //取值
//checkCode=checkCode.toUpperCase();  //把字符全部转换为大写的（此语句可以用于验证码不区分大小写）
resp.setContentType("text/html;charset=gbk");//解决乱码问题

if(checkCode.equals(piccode)){
User use=userServive.login(user);
if(use!=null){
String [] ischeck=req.getParameterValues("ischeck");
if(ischeck!=null&&"true".equals(ischeck[0])){
//添加cookie信息
Cookie usernameCookie=new Cookie("username", username);
Cookie passwordCookie=new Cookie("password",password );
usernameCookie.setMaxAge(60*60*24*1);//一天
passwordCookie.setMaxAge(60*60*24*1);
resp.addCookie(usernameCookie);
resp.addCookie(passwordCookie);
}
resp.sendRedirect("loginSuccess.jsp");
}else{
resp.sendRedirect("loginFail.jsp");
}
}else{
resp.sendRedirect("loginFail.jsp");
}
}

验证码写不对怎么都登录不了不是吗？

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