spring mvc 使用kaptcha生成验证码

By default, Kaptcha is very easy to setup and use and the default output produces a captcha that should be fairly hard to bust. The captcha's it produces by default look very similar to the one above. If you would like to change the look of the output, there is several configuration options and the framework is modular so you can write your own morphing code.

下载kaptcha-2.3.2.jar

http://code.google.com/p/kaptcha/downloads/list

1.spring 配置文件 applicationContext.xml

	
		
			
				
					
						yes
						105,179,90
						blue
						125
						45
						45
						code
						4
						宋体,楷体,微软雅黑
					
				
			
		
	

2. Controller的实现

package com.vopzoon.app.base.captcha;

import java.awt.image.BufferedImage;

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

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.Constants;
import com.google.code.kaptcha.Producer;

/**
 * 防止Captcha机器人登陆
 * @author liuwang
 *
 */
@Controller
@RequestMapping("/kaptcha/*")
public class CaptchaController {
	
	@Autowired
	private Producer captchaProducer = null;

	@RequestMapping
	public ModelAndView getKaptchaImage(HttpServletRequest request, HttpServletResponse response) throws Exception {
		HttpSession session = request.getSession();
		String code = (String)session.getAttribute(Constants.KAPTCHA_SESSION_KEY);
		System.out.println("******************验证码是: " + code + "******************");
		
		response.setDateHeader("Expires", 0);
		
		// Set standard HTTP/1.1 no-cache headers.
		response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
		
		// Set IE extended HTTP/1.1 no-cache headers (use addHeader).
		response.addHeader("Cache-Control", "post-check=0, pre-check=0");
		
		// Set standard HTTP/1.0 no-cache header.
		response.setHeader("Pragma", "no-cache");
		
		// return a jpeg
		response.setContentType("image/jpeg");
		
		// create the text for the image
		String capText = captchaProducer.createText();
		
		// store the text in the session
		session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
		
		// create the image with the text
		BufferedImage bi = captchaProducer.createImage(capText);
		ServletOutputStream out = response.getOutputStream();
		
		// write the data out
		ImageIO.write(bi, "jpg", out);
		try {
			out.flush();
		} finally {
			out.close();
		}
		return null;
	}

}

3. JSP代码

<%@ page language="java" contentType="text/html; charset=UTF-8"
	pageEncoding="UTF-8"%>












		

      验证码:
                   
      
      

      
      看不清?换一张

4.controller中取得校验码

String kaptchaExpected = (String) request.getSession().getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY);

5.kaptcha可配置项

kaptcha.border  是否有边框  默认为true  我们可以自己设置yes，no
kaptcha.border.color   边框颜色   默认为Color.BLACK
kaptcha.border.thickness  边框粗细度  默认为1
kaptcha.producer.impl   验证码生成器  默认为DefaultKaptcha
kaptcha.textproducer.impl   验证码文本生成器  默认为DefaultTextCreator
kaptcha.textproducer.char.string   验证码文本字符内容范围  默认为abcde2345678gfynmnpwx
kaptcha.textproducer.char.length   验证码文本字符长度  默认为5
kaptcha.textproducer.font.names    验证码文本字体样式  默认为new Font("Arial", 1, fontSize), new Font("Courier", 1, fontSize)
kaptcha.textproducer.font.size   验证码文本字符大小  默认为40
kaptcha.textproducer.font.color  验证码文本字符颜色  默认为Color.BLACK
kaptcha.textproducer.char.space  验证码文本字符间距  默认为2
kaptcha.noise.impl    验证码噪点生成对象  默认为DefaultNoise
kaptcha.noise.color   验证码噪点颜色   默认为Color.BLACK
kaptcha.obscurificator.impl   验证码样式引擎  默认为WaterRipple
kaptcha.word.impl   验证码文本字符渲染   默认为DefaultWordRenderer
kaptcha.background.impl   验证码背景生成器   默认为DefaultBackground
kaptcha.background.clear.from   验证码背景颜色渐进   默认为Color.LIGHT_GRAY
kaptcha.background.clear.to   验证码背景颜色渐进   默认为Color.WHITE
kaptcha.image.width   验证码图片宽度  默认为200
kaptcha.image.height  验证码图片高度  默认为50