                        課程
                    
                        /后端開發(fā)
                        
                            /Java
                        
                        /Java實現(xiàn)驗證碼制作

為什么按照教程寫的一樣不能顯示驗證碼？是哪里錯了嗎？

//index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>

<%

String path = request.getContextPath();

String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";

%>

<html>

? <head>

? ?

? ??

function reloadCode(){

var time=new Date().getTime();

document.getElementById("imagecode").src="<%=request.getContextPath() %>/servlet/ImgeServlet?d="+time;

}

</script>

? </head>

??

? <body>

? ? 驗證碼：<input type="text" name="checkcode">

? ? <img alt="驗證碼" id="imagecode" src="<%=request.getContextPath() %>/servlet/ImgeServlet"/> ?

? ? <a href="javascript:reloadCode();">看不清 </a> <br>

? </body>

</html>

?

//ImageServlet.java

package com.muke;

import java.awt.Color;

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.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class ImageServlet extends HttpServlet{

public ?void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException{

BufferedImage bi = new BufferedImage(80, 22, BufferedImage.TYPE_INT_RGB);

//畫一個圖片

Graphics g=bi.getGraphics();

Color c=new Color(200,150,255);

g.setColor(c);

g.fillRect(0, 0, 80, 22);

//背景圖片內(nèi)容

char[] ch="ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".toCharArray();

//隨機獲取四個字符

Random r=new Random();

int len=ch.length,index;

//定義一個

StringBuffer sb=new StringBuffer();

for(int i=0;i<4;i++){

index=r.nextInt(len);

//隨機顏色

g.setColor(new Color(r.nextInt(88),r.nextInt(188),r.nextInt(255)));

//將字符畫到圖片上

g.drawString(ch[index]+"", (i*15)+3, 18);

//將字符保存起來

sb.append(ch[index]);

}

//將字符保存在

request.getSession().setAttribute("piccode", sb.toString());

//進行輸出

ImageIO.write(bi,"JPG",response.getOutputStream());

?

}

//web.xml

<?xml version="1.0" encoding="UTF-8"?>

<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"

?xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee ? http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

?<servlet>

? <servlet-name>ImageServlet</servlet-name>

? <servlet-class>com.muke.ImageServlet</servlet-class>

?</servlet>

?<servlet-mapping>

? <servlet-name>ImageServlet</servlet-name>

? <url-pattern>/servlet/ImageServlet</url-pattern>

?</servlet-mapping>

?<welcome-file-list>

? <welcome-file>index.jsp</welcome-file>

?</welcome-file-list>

?<login-config>