一、基本流程:
产生一个验证码页面(很小)→嵌入到表单中→点击可以刷新页面→表单提交时验证。
二、方法:
1、定义TestAction,实现画图方法
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package com.zhuguang.action; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Map; import javax.servlet.http.HttpServletResponse; import org.apache.struts2.interceptor.ServletResponseAware; import org.apache.struts2.interceptor.SessionAware; import com.opensymphony.xwork2.ActionSupport; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class TestAction extends ActionSupport implements SessionAware,ServletResponseAware { private Map<String, Object> session; private HttpServletResponse response; private static final long serialVersionUID = 1L; private String chknumber; @Override public String execute() throws Exception { response.setHeader( "Cache-Control" , "no-cache" ); int height= 20 ; //图片高度 BufferedImage image= new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB); Graphics graphics=image.createGraphics(); graphics.setColor( this .getColor()); //背景颜色 graphics.fillRect( 0 , 0 , width, height); graphics.setFont( new Font( "Arial" ,Font.BOLD, 18 )); graphics.setColor( this .getColor()); //字的颜色 String number=String.valueOf(System.currentTimeMillis()% 9000 + 1000 ); //生成四位随机数 session.put( "randomCode" , number); //写入session中 graphics.drawString(number, ( int )(width* 0.1 ), ( int )(height* 0.8 )); graphics.dispose(); JPEGImageEncoder encoder=JPEGCodec.createJPEGEncoder(response.getOutputStream()); encoder.encode(image); response.getOutputStream().flush(); //刷新到页面生成图片 response.getOutputStream().close(); //关闭writer return null ; } private Color getColor(){ int red=( int )(Math.random()* 1000 % 256 ); int green=( int )(Math.random()* 1000 % 256 ); int blue=( int )(Math.random()* 1000 % 256 ); return new Color(red,green,blue); } public String getChknumber() { return chknumber; } public void setChknumber(String chknumber) { this .chknumber = chknumber; } @Override public void setSession(Map<String, Object> session) { // TODO Auto-generated method stub this .session = session; } @Override public void setServletResponse(HttpServletResponse response) { // TODO Auto-generated method stub this .response = response; } } |
注意用到session和response
2、在struts.xml文件中注册:
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<action name= "randomCode" class = "com.zhuguang.action.TestAction" > </action> |
其中不返回任何信息,这样就不会跳转页面
3、jsp页面编写
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<%@ page language= "java" contentType= "text/html; charset=UTF-8" pageEncoding= "UTF-8" %> <% @taglib uri= "/struts-tags" prefix= "s" %> <% 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" > <script type= "text/javascript" > <!-- function reloadcode(obj,base){ var rand= new Date().getTime(); //这里用当前时间作为参数加到url中,是为了使URL发生变化,这样验证码才会动态加载, //只是一个干扰作用,无确实意义,但却又非常巧妙,呵呵 obj.src=base+ "randomCode.action?abc=" +rand; //其实服务器端是没有abc的字段的。 } //--> </script> <title>测试页面</title> </head> <body> <form action= "testLogin" method= "post" > Username<input type= "text" name= "name" ><br> Password<input type= "text" name= "password" ><br> 验证码:<input type= "text" name= "chknumber" id= "chknumber" maxlength= "4" class = "chknumber_input" > <img id="codetool">
4、验证 (1)在Action中添加一个验证方法
(2)在struts.xml中进行注册
以上所述是小编给大家介绍的Struts2实现生成动态验证码并验证实例代码,希望对大家有所帮助! 相关文章
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