Java乔晓松-Struts2用Action实现的验证码

package www.csdn.dbshop.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.imageio.stream.ImageOutputStream;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

/**
 * ImageAction 2013-3-26 下午3:44:26
 * 
 * @author 乔晓松
 * 有疑问的请发送邮件到965266509@qq.com
 */
public class ImageCheck extends ActionSupport {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private ByteArrayInputStream inputStream; 
	public void setInputStream(ByteArrayInputStream inputStream) {   
        this.inputStream = inputStream;   
    }   
    public ByteArrayInputStream getInputStream() {   
        return inputStream;   
    }  
    public String execute() throws Exception{   
//       在内存中创建图象   
        int width=65, height=20;   
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);   
//       获取图形上下文   
        Graphics g = image.getGraphics();   
//      生成随机类   
        Random random = new Random();   
//       设定背景色   
        g.setColor(getRandColor(200,250));   
        g.fillRect(0, 0, width, height);   
//      设定字体   
        g.setFont(new Font("Times New Roman",Font.PLAIN,18));   
//       随机产生155条干扰线，使图象中的认证码不易被其它程序探测到   
        g.setColor(getRandColor(160,200));   
        for (int i=0;i<155;i++)   
        {   
         int x = random.nextInt(width);   
         int y = random.nextInt(height);   
                int xl = random.nextInt(12);   
                int yl = random.nextInt(12);   
         g.drawLine(x,y,x+xl,y+yl);   
        }   
//       取随机产生的认证码(6位数字)   
        String sRand="";   
        for (int i=0;i<4;i++){   
            String rand=String.valueOf(random.nextInt(10));   
            sRand+=rand;   
            // 将认证码显示到图象中   
            g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));   
//      调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成   
            g.drawString(rand,13*i+6,16);   
        }   
//       将认证码存入SESSION   
        ActionContext.getContext().getSession().remove("randimg");
        ActionContext.getContext().getSession().put("randimg",sRand);   
//       图象生效   
        g.dispose();   
        ByteArrayOutputStream output = new ByteArrayOutputStream();   
        ImageOutputStream imageOut = ImageIO.createImageOutputStream(output);   
        ImageIO.write(image, "JPEG", imageOut);   
        imageOut.close();   
        ByteArrayInputStream input = new ByteArrayInputStream(output.toByteArray());   
        this.setInputStream(input);   
        return SUCCESS;   
    }   
    /*   
     * 给定范围获得随机颜色   
     */   
    private Color getRandColor(int fc,int bc){   
        Random random = new Random();   
        if(fc>255) fc=255;   
        if(bc>255) bc=255;   
        int r=fc+random.nextInt(bc-fc);   
        int g=fc+random.nextInt(bc-fc);   
        int b=fc+random.nextInt(bc-fc);   
        return new Color(r,g,b);   
   }   
     
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
	"-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
	"http://struts.apache.org/dtds/struts-2.3.dtd">

<struts>
	<package name="imagecheck" namespace="/csdn" extends="json-default">
	<global-results>
	<result name="input">/backstage/image/image_list.jsp</result>
	</global-results>
		<action name="ImageCheck_*" class="www.csdn.dbshop.action.ImageCheck"
			method="{1}">
			<result name="success" type="stream">
                 <param name="contentType">image/jpeg</param>
                 <param name="inputName">inputStream</param>               
             </result>
		</action>
	</package>
</struts>