Spring整合Kaptcha谷歌验证码工具的开发步骤

<dependency>
  <groupId>com.google.code.kaptcha</groupId>
  <artifactId>kaptcha</artifactId>
  <version>2.3</version>
</dependency>

mvn install:install-file -Dfile=jar文件的位置 -DgroupId=目标安装的groupid -DartifactId=目标安装的artifactId

-Dpackaging=jar -Dversion=版本号

<?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.xsd">

  <bean id="captchaProducer" class="com.google.code.kaptcha.impl.DefaultKaptcha">
    <property name="config">
      <bean class="com.google.code.kaptcha.util.Config">
        <constructor-arg>
          <props>
            <!-- 是否显示边框 -->
            <prop key="kaptcha.border">yes</prop>
            <!-- 边框颜色 -->
            <prop key="kaptcha.border.color">105,179,90</prop>
            <!-- 验证码字体颜色 -->
            <prop key="kaptcha.textproducer.font.color">blue</prop>
            <!-- 验证码的宽 -->
            <prop key="kaptcha.image.width">125</prop>
            <!-- 验证码的高 -->
            <prop key="kaptcha.image.height">45</prop>
            <!-- 验证码的字体大小 -->
            <prop key="kaptcha.textproducer.font.size">45</prop>
            <!-- 验证码的session key -->
            <prop key="kaptcha.session.key">code</prop>
            <!-- 验证码个数 -->
            <prop key="kaptcha.textproducer.char.length">4</prop>
            <!-- 验证码的字体 -->
            <prop key="kaptcha.textproducer.font.names">宋体,楷体,微软雅黑</prop>
          </props>
        </constructor-arg>
      </bean>
    </property>
  </bean>
</beans>

import com.google.code.kaptcha.Constants;
import com.google.code.kaptcha.Producer;
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 javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;

@Controller
public class KaptchaController {

  @Autowired
  private Producer captchaProducer;

  @RequestMapping(value = "verification", method = RequestMethod.GET)
  public ModelAndView verification(HttpServletRequest request, HttpServletResponse response) throws IOException {
    System.out.println("进入生成验证码控制层");
    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");

    // 返回一个图片
    response.setContentType("image/jpeg");

    // 创建text文本在图片中
    String capText = captchaProducer.createText();

    // 将文本内容存储在session中
    request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, capText);

    // 用文本创建图像
    BufferedImage bi = captchaProducer.createImage(capText);
    //servlet输出流
    ServletOutputStream out = response.getOutputStream();
    // 写出数据
    ImageIO.write(bi, "jpg", out);

    try {
      // 提交
      out.flush();
    } finally {
      // 提交后将输出流关闭
      out.close();
    }
    return null;
  }
}

<img id="verification" src="/verification" style="cursor: pointer;" title="看不清？换一张" />

//换验证码事件
$("#verification").click(function () {
  $(this).attr("src","verification");
})

//比较验证码
//Constants.KAPTCHA_SESSION_KEY 是之前生成验证码存在session中的
//code是用户点击提交后，通过name属性发送到控制层的内容，为用户输入的内容
if(!(code.equals(session.getAttribute(Constants.KAPTCHA_SESSION_KEY)))){
  //如果用户输入的内容与session中的内容不一致返回登录页面
  return "login";
}