captcha验证码

[size=large]jsp相关的

<%!
// 给定范围获得随机颜色
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);
}
%>
<%
//设置页面不缓存
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);

// 在内存中创建图象
int width = 60, 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));

//画边框
//g.setColor(new Color());
//g.drawRect(0,0,width-1,height-1);


// 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
    // 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.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
    g.drawString(rand, 13 * i + 6, 16);
}

// 将认证码存入SESSION
session.setAttribute("vcode", sRand);

// 图象生效
g.dispose();

// 输出图象到页面
ImageIO.write(image, "JPEG", response.getOutputStream());

out.clear();
out = pageContext.pushBody();

%>

xml相关的

<?xml version="1.0" encoding="utf-8"?>

<beans
	xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="
		http://www.springframework.org/schema/beans
		http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
	
	<!-- 图片验证码构造器 -->
	<bean id="captchaProducer"
		class="com.google.code.kaptcha.impl.DefaultKaptcha">
		<property name="config">
			<bean class="com.google.code.kaptcha.util.Config">
				<constructor-arg>
					<props>
						<prop key="kaptcha.border">no</prop>
						<prop key="kaptcha.border.color">105,179,90</prop>
						<prop key="kaptcha.image.width">250</prop>
						<prop key="kaptcha.image.height">90</prop>
						<prop key="kaptcha.session.key">code</prop>
						<prop key="kaptcha.noise.color">blue</prop>
						<prop key="kaptcha.textproducer.char.length">4</prop>
						<prop key="kaptcha.textproducer.font.color">black</prop>
						<prop key="kaptcha.textproducer.font.size">70</prop>
						<prop key="kaptcha.textproducer.font.names">宋体,楷体,微软雅黑</prop>
					</props>
				</constructor-arg>
			</bean>
		</property>
	</bean>
</beans>

controller相关的

package com.mysns.web.controller;

import java.awt.image.BufferedImage;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import com.google.code.kaptcha.Producer;

/**
 * 利用 kaptcha 来生成验证码图片.
 * 
 * @author 
 */
@Controller
@RequestMapping(value = "/kaptcha")
public class KaptchaController {

	/**
	 * kaptcha的生成器, 具体配置见 "applicationContext-kaptcha.xml"
	 */
	@Autowired
	private Producer producer;
	
	@RequestMapping(value = "/image")
	public ModelAndView hadleRequest(HttpServletRequest request,
			HttpServletResponse response) throws IOException {
		
		// 设置工作模式为headless
		System.setProperty("java.awt.headless", "true");
		
		// 设置页面不缓存
		response.setHeader("Pragma", "No-cache");
	    response.setHeader("Cache-Control", "no-cache");
	    response.setDateHeader("Expires", 0);
		response.setContentType("image/jpeg");
		
		// 给图片创建文字验证码
		String capText = producer.createText();
		
		// 将验证码存入session
		request.getSession().setAttribute(
				com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY, capText);
		
		// 在内存中创建图片
		BufferedImage bufferedImg = producer.createImage(capText);
		
		//输出图象到页面
	    ImageIO.write(bufferedImg, "JPEG", response.getOutputStream());
	    
		return null;
	}
}

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