日期:2014-05-16  浏览次数:20384 次

struts2 jsp 验证码 实例
package org.apache.struts.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;

public class RandomPictureAction extends ActionSupport {

	/**
	 * 
	 */
	private static final long serialVersionUID = -6950908478971552308L;

	private ByteArrayInputStream inputStream;

	public String execute() throws Exception {
		// 在内存中创建图象
		int width = 85, 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 < 6; 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().put("rand", 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);
	}

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

	public ByteArrayInputStream getInputStream() {
		return inputStream;
	}

}
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">

<struts>

	<constant name="struts.devMode" value="true" />

	<package name="randpicture" extends="struts-default">

		<action name="rand" class="org.apache.struts.action.RandomPictureAction">
			<result type="stream">
				<param name="contentType">image/jpeg</param>
				<param name="inputName">inputStream</param>
			</result>
		</action>
		
	</package>

</struts>

?

<?xml version="1.0" encoding="ISO-8859-1" ?>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<s:head />
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
<title>Random Picture</title>
</head>
<body>
<script type="text/ja