struts1生成驗證碼

package com.bonc.security.login.action;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import com.bonc.javax.struts.BONCExAction;
import com.bonc.javax.struts.BONCModel;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

/**
 * 
 * Title:專題分析>>業務異動監控>>3G業務>>渠道監控>>Iphone售點銷量 Description:Iphone售點銷量 Copyright:
 * Copyright (c) 2013 Company: 北京東方國信公司
 * 
 * @author pcl
 * @version 1.0
 */
public class GetVerifycodeAction extends BONCExAction {

	public static final char[] chars = { '2', '3', '4', '5', '6', '7', '8',
			'9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M',
			'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z' };
	public static Random random = new Random();

	/**
	 * 產生4位隨機數0,o,1,i類似字符除外
	 * 
	 * @return
	 */
	public static String getRandom() {
		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < 4; i++) {
			buffer.append(chars[random.nextInt(chars.length)]);
		}
		return buffer.toString().toUpperCase();
	}

	/**
	 * 產生隨機顏色
	 * 
	 * @return
	 */
	public static Color getRandomColor() {
		Color color = new Color(random.nextInt(255), random.nextInt(255),
				random.nextInt(255));
		return color;
	}

	/**
	 * 隨機產生顏色的反色
	 * 
	 * @param c
	 * @return
	 */
	public static Color getReverseColor(Color c) {
		Color color = new Color(255 - c.getRed(), 255 - c.getGreen(),
				255 - c.getBlue());
		return color;
	}

	@Override
	public BONCModel control(ActionMapping arg0, ActionForm arg1,
			HttpServletRequest arg2, HttpServletResponse arg3, BONCExAction arg4) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public ActionForward forward(ActionMapping arg0, ActionForm arg1,
			HttpServletRequest arg2, HttpServletResponse arg3, Object arg4) {
		String param=arg2.getParameter("isVerify");
		if("1".equals(param)){
			String verifycode=arg2.getParameter("verifycode") == null ? "" : arg2.getParameter("verifycode").trim().toUpperCase();
			String randomString =(String) arg2.getSession().getAttribute("randomString");
			arg3.setContentType("application/json;charset=UTF-8");
			if(verifycode.equals(randomString)){
				try {
					arg3.getWriter().write("1");
				} catch (IOException e) {
					e.printStackTrace();
				}
			}else{
				try {
					arg3.getWriter().write("0");
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			return null;
		}else{
			// TODO Auto-generated method stub
			// 設置輸出類型爲圖片
			arg3.setContentType("image/jpeg");
			String randomString = getRandom();
			arg2.getSession(true).setAttribute("randomString", randomString);
			int width = 60, height = 20;
			Color randomColor = getRandomColor();
			Color reverseColor = getReverseColor(randomColor);
			// 建立一個顏色圖片
			BufferedImage bi = new BufferedImage(width, height,
					BufferedImage.TYPE_INT_RGB);
			// 獲取繪圖對象
			Graphics2D g = bi.createGraphics();
			// 設置顏色
			g.setColor(randomColor);
			// 繪製背景
			g.fillRect(0, 0, width, height);
			// 設置反射色
			g.setColor(reverseColor);
			// 設置字體
			g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
			// 繪製字符
			g.drawString(randomString, 5, 15);
			// 繪製噪音點 最多100個
			for (int i = 0, n = random.nextInt(40); i < n; i++) {
				g.drawRect(random.nextInt(width), random.nextInt(height), 1, 1);
			}
			try {
				ServletOutputStream out = arg3.getOutputStream();
				// 轉成JPEG格式
				JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
				// 對圖片編碼
				encoder.encode(bi);
				// 輸出到客戶端
				out.flush();
				out.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
			return null;
		}
	}
}