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
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 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 width=50; //图片宽度
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 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：
其中不返回任何信息，这样就不会跳转页面
3、jsp页面编写
<%@ 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+"/"; %>测试页面
4、验证
（1）在Action中添加一个验证方法
public String testLogin()
{
if(session.get("randomCode").equals(chknumber))
{
return SUCCESS;
}
else
{
return ERROR;
}
}
（２）在struts.xml中进行注册
success.jsp error.jsp
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！
