struts2-一个请求-Action却执行两次响应
<IMG id=geneValidCode alt=验证码 src="random.shtml" align=absMiddle border=0>
package com.game.web.action;import java.io.ByteArrayInputStream;import javax.servlet.http.HttpServletResponse;import org.apache.struts2.ServletActionContext;import com.game.web.util.RandomNumUtil;import com.opensymphony.xwork2.ActionContext;import com.opensymphony.xwork2.ActionSupport;public class RandomAction extends ActionSupport { private static final long serialVersionUID = 1L; private ByteArrayInputStream inputStream; public String execute() throws Exception { HttpServletResponse response = ServletActionContext.getResponse(); response.setHeader("Pragma","No-cache"); response.setHeader("Cache-Control","no-cache"); response.setHeader("Cache-Control", "no-store"); response.setDateHeader("Expires", 0); RandomNumUtil rdnu=RandomNumUtil.Instance(); this.setInputStream(rdnu.getImage()); ActionContext.getContext().getSession().put("random", rdnu.getString()); return SUCCESS; } public void setInputStream(ByteArrayInputStream inputStream) { this.inputStream = inputStream; } public ByteArrayInputStream getInputStream() { return inputStream; }}package com.game.web.util;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;/*** Project:* Filename: RandomNumUtil.java* Company: * Copyright: * Description: 验证码生成器* Date */public class RandomNumUtil { private ByteArrayInputStream image;// 图像 private String str;// 验证码 private RandomNumUtil() { init();// 初始化属性 } /* * 取得RandomNumUtil实例 */ public static RandomNumUtil Instance() { return new RandomNumUtil(); } /* * 取得验证码图片 */ public ByteArrayInputStream getImage() { return this.image; } /* * 取得图片的验证码 */ public String getString() { return this.str; } private void init() { // 在内存中创建图象 int width = 52, 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(4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); } // 赋值验证码 this.str = sRand; // 图象生效 g.dispose(); ByteArrayInputStream input = null; ByteArrayOutputStream output = new ByteArrayOutputStream(); try { ImageOutputStream imageOut = ImageIO .createImageOutputStream(output); ImageIO.write(image, "JPEG", imageOut); imageOut.close(); input = new ByteArrayInputStream(output.toByteArray()); } catch (Exception e) { System.out.println("验证码图片产生出现错误：" + e.toString()); } this.image = input;/* 赋值图像 */ } /* * 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); }}