struts2生成随机验证码图片

之前想做一个随机验证码的功能，自己也搜索了一下别人写的代码，然后自己重新用struts2实现了一下，现在将我自己实现代码贴出来！大家有什么意见都可以指出来！

首先是生成随机验证码图片的action：

CreateImageAction:

package com.xiaoluo.action;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext; 

import com.opensymphony.xwork2.ActionSupport;

public class CreateImageAction extends ActionSupport
{
private ByteArrayInputStream inputStream;

private static int WIDTH = 60;

private static int HEIGHT = 20;

public ByteArrayInputStream getInputStream()
    {
return inputStream;
    }

public void setInputStream(ByteArrayInputStream inputStream)
    {
this.inputStream = inputStream;
    }

private static String createRandom()
    {
        String str = "0123456789qwertyuiopasdfghjklzxcvbnm";

char[] rands = new char[4];

        Random random = new Random();

for (int i = 0; i < 4; i++)
        {
            rands[i] = str.charAt(random.nextInt(36));
        }

return new String(rands);
    }

private void drawBackground(Graphics g)
    {
// 画背景
        g.setColor(new Color(0xDCDCDC));

        g.fillRect(0, 0, WIDTH, HEIGHT);

// 随机产生 120 个干扰点

for (int i = 0; i < 120; i++)
        {
int x = (int) (Math.random() * WIDTH);

int y = (int) (Math.random() * HEIGHT);

int red = (int) (Math.random() * 255);

int green = (int) (Math.random() * 255);

int blue = (int) (Math.random() * 255);

            g.setColor(new Color(red, green, blue));

            g.drawOval(x, y, 1, 0);
        }
    }

private void drawRands(Graphics g, String rands)
    {
        g.setColor(Color.BLACK);

        g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 18));

// 在不同的高度上输出验证码的每个字符

        g.drawString("" + rands.charAt(0), 1, 17);

        g.drawString("" + rands.charAt(1), 16, 15);

        g.drawString("" + rands.charAt(2), 31, 18);

        g.drawString("" + rands.charAt(3), 46, 16);

        System.out.println(rands);

    }

    @Override
public String execute() throws Exception
    {
        HttpServletResponse response = ServletActionContext.getResponse();

// 设置浏览器不要缓存此图片
        response.setHeader("Pragma", "no-cache");

        response.setHeader("Cache-Control", "no-cache");

        response.setDateHeader("Expires", 0);

        String rands = createRandom();

        BufferedImage image = new BufferedImage(WIDTH, HEIGHT,
                BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

// 产生图像
        drawBackground(g);

        drawRands(g, rands);

// 结束图像 的绘制 过程， 完成图像
        g.dispose();

        ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

        ImageIO.write(image, "jpeg", outputStream);

        ByteArrayInputStream input = new ByteArrayInputStream(outputStream
                .toByteArray());

this.setInputStream(input);

        HttpSession session = ServletActionContext.getRequest().getSession();

        session.setAttribute("checkCode", rands);

        input.close();

        outputStream.close();

return SUCCESS;
    }
}

以上是生成随机验证码图片的action，将生成的随机数放到session里，然后页面提交到验证随机数的action:

LoginValidateAction:

package com.xiaoluo.action;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginValidateAction extends ActionSupport
{
private String checkCode;

public String getCheckCode()
    {
return checkCode;
    }

public void setCheckCode(String checkCode)
    {
this.checkCode = checkCode;
    }

    @Override
public String execute() throws Exception
    {
return SUCCESS;
    }

    @Override
public void validate()
    {
        HttpSession session = ServletActionContext.getRequest().getSession();

        String checkCode2 = (String)session.getAttribute("checkCode");

if(!checkCode.equals(checkCode2))
        {
this.addActionError("输入的验证码不正确，请重新输入！");
        }
    }
}

下面是struts.xml配置部分代码:

　　　　　　<action name="createImageAction" class="com.xiaoluo.action.CreateImageAction">
<result name="success" type="stream">
<param name="contentType">image/jpeg</param>
<param name="inputName">inputStream</param>
</result>
　　　　　　  </action>

<action name="loginValidateAction" class="com.xiaoluo.action.LoginValidateAction">
<result name="success">/success.jsp</result>
<result name="input">/login.jsp</result>
</action>

最后就是jsp部分的代码:

login.jsp:

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<html>
<head>
<base href="<%=basePath%>">

<title>My JSP 'login.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
    <link rel="stylesheet" type="text/css" href="styles.css">
-->

</head>

<body>

<h3><font color="blue">带有验证码的登陆界面</font></h3>

<s:form action="loginValidateAction.action" theme="simple">

        用户名:<s:textfield name="username"></s:textfield><br>
        密码    :<s:password name="password"></s:password><br>
        验证码:<s:textfield name="checkCode"></s:textfield>
　　　　　
　　　　　<!--若要点击图片刷新，重新得到一个验证码，要在后面加上个随机数，这样保证每次提交过去的都是不一样的path，防止因为缓存而使图片不刷新-->
<img src="createImageAction.action" onclick="this.src='createImageAction.action?'+ Math.random()" title="点击图片刷新验证码"/><br>
<s:actionerror cssStyle="color:red"/>

<s:submit value="提交"></s:submit>

</s:form>

</body>
</html>

到此，就完成用struts2生成随机验证码图片以及实现登陆验证啦！