为什么80%的码农都做不了架构师？>>> 
如题。首先，在pom.xml文件中引用如下资源库：
com.github.penggle
kaptcha
2.3.2
javax.servlet-api
javax.servlet
在系统默认classpath下面的application.properties文件中，加入图形验证码配置参数：
#图形验证码相关配置
kaptcha.border=yes
kaptcha.borderColor=105,179,90
kaptcha.textProducerFontColor=black
kaptcha.textProducerFontSize=30
kaptcha.textProducerFontNames=Arial,\u5b8b\u4f53
kaptcha.textProducerCharLength=4
kaptcha.imageWidth=100
kaptcha.imageHeight=35
kaptcha.noiseColor=green
kaptcha.noiseImpl=com.google.code.kaptcha.impl.NoNoise
kaptcha.obscurificatorImpl=com.google.code.kaptcha.impl.ShadowGimpy
kaptcha.sessionKey=kaptcha.code
kaptcha.sessionDate=kaptcha.date
创建图形验证码的属性文件，注意，别忘记加入前缀： prefix = "kaptcha"
package com.my;
import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties(prefix = "kaptcha")
public class KaptchaProperties {
private String border;
private String borderColor;
private String textProducerFontColor;
private String textProducerFontSize;
private String textProducerFontNames;
private String textProducerCharLength;
private String imageWidth;
private String imageHeight;
private String noiseColor;
private String noiseImpl;
private String obscurificatorImpl;
private String sessionKey;
private String sessionDate;
// 以下省略了各个属性的getter和setter
}然后创建将属性自动注入DefaultKaptcha的配置类KaptchaAutoConfiguration：
package com.my;
import java.util.Properties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.impl.DefaultKaptcha;
import com.google.code.kaptcha.util.Config;
@Configuration
@EnableConfigurationProperties(KaptchaProperties.class)
public class KaptchaAutoConfiguration {
@Autowired
private KaptchaProperties kaptchaProperties;
@Bean(name = "kaptchaProducer")
public DefaultKaptcha getKaptchaBean() {
DefaultKaptcha defaultKaptcha = new DefaultKaptcha();
Properties properties = new Properties();
properties.setProperty(Constants.KAPTCHA_BORDER, kaptchaProperties.getBorder());
properties.setProperty(Constants.KAPTCHA_BORDER_COLOR, kaptchaProperties.getBorderColor());
properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_COLOR, kaptchaProperties.getTextProducerFontColor());
properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_SIZE, kaptchaProperties.getTextProducerFontSize());
properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_FONT_NAMES, kaptchaProperties.getTextProducerFontNames());
properties.setProperty(Constants.KAPTCHA_TEXTPRODUCER_CHAR_LENGTH, kaptchaProperties.getTextProducerCharLength());
properties.setProperty(Constants.KAPTCHA_IMAGE_WIDTH, kaptchaProperties.getImageWidth());
properties.setProperty(Constants.KAPTCHA_IMAGE_HEIGHT, kaptchaProperties.getImageHeight());
properties.setProperty(Constants.KAPTCHA_NOISE_COLOR, kaptchaProperties.getNoiseColor());
//properties.setProperty(Constants.KAPTCHA_NOISE_IMPL, kaptchaProperties.getNoiseImpl());//去掉干扰线
properties.setProperty(Constants.KAPTCHA_OBSCURIFICATOR_IMPL, kaptchaProperties.getObscurificatorImpl());//阴影渲染效果
properties.setProperty(Constants.KAPTCHA_SESSION_KEY, kaptchaProperties.getSessionKey());
properties.setProperty(Constants.KAPTCHA_SESSION_DATE, kaptchaProperties.getSessionDate());
Config config = new Config(properties);
defaultKaptcha.setConfig(config);
return defaultKaptcha;
}
}
最后，在controller里，完成图片生成和图形验证码校验：
package com.my.controller;
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.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.Producer;
import com.ixinnuo.uums.frame.ReturnData;
@Controller
@RequestMapping("/kaptcha")
public class KaptchaController {
@Autowired
private Producer kaptchaProducer;
/**
* 获取验证码图片
* @param request
* @param response
* @return
* @throws Exception
*/
@RequestMapping(value="/getKaptchaImage",method=RequestMethod.GET)
public ModelAndView getKaptchaImage(HttpServletRequest request, HttpServletResponse response) throws Exception {
HttpSession session = request.getSession();
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 = kaptchaProducer.createText();
// store the text in the session
session.setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);
// create the image with the text
BufferedImage bi = kaptchaProducer.createImage(capText);
ServletOutputStream out = response.getOutputStream();
// write the data out
ImageIO.write(bi, "jpg", out);
try {
out.flush();
} finally {
out.close();
}
return null;
}
/**
* 检验图片验证码
* @param clientCode
* @param request
* @param response
* @throws Exception
*/
@RequestMapping(value="/checkKaptcha",method=RequestMethod.GET)
public void checkKaptcha(String clientCode,HttpServletRequest request, HttpServletResponse response) throws Exception{
ObjectMapper mapper = new ObjectMapper();
HttpSession session = request.getSession();
String serverCode = (String) session.getAttribute(Constants.KAPTCHA_SESSION_KEY);
response.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=UTF-8");
if(clientCode != null && clientCode.equalsIgnoreCase(serverCode)){
mapper.writeValue(response.getOutputStream(), new ReturnData(0));
}else{
mapper.writeValue(response.getOutputStream(), new ReturnData(2004));
}
}
}