用Struts2生成验证码，验证码图片显示不出来。

Question

最近在学Struts2，有一个题目是使用Struts2写一个有验证码的登陆界面。但是怎么试验证码都出不来，麻烦各位大神帮我解决下。谢谢。

界面

LoginValidateAction.java

package cn.edu.xmut.action;

import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class LoginValidateAction extends ActionSupport
{
/**
*
*/
private static final long serialVersionUID = 1L;
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！");
    }
}

}

CreateImageAction.java

package cn.edu.xmut.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 static final long serialVersionUID = 1L;
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;
}

}

struts.xml配置

image/jpeg
inputStream



/success.jsp
/login.jsp

login.jsp

image/jpeg
inputStream



/success.jsp
/login.jsp

Answer 1

Struts2.jsp

    <action name="cteateImageAction" class="cn.edu.xmut.action.CreateImageAction">
         <result name = "success" type="stream">
            <param name = "contentType">image/jpeg</param>
            <param name = "inputName">inputStream</param>
         </result>
         </action>
          <action name="loginValidateAction" class="cn.edu.xmut.action.LoginValidateAction">
                <result name="success">/success.jsp</result>
                <result name="input">/login.jsp</result>
            </action>

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>