验证码

我使用的是maven项目，先去下载captcha-2.3.2.jar,我再传入项目的私服，如果不是maven项目可以直接引入下载好的jar包

1：pom.xml配置

<dependency>
          <groupId>com.google</groupId>
          <artifactId>code-kaptcha</artifactId>
          <version>2.3.2</version>

</dependency>

2：applicationContext.xml配置加上一下

 <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.textproducer.font.color">blue</prop>  
                        <prop key="kaptcha.image.width">125</prop>  
                        <prop key="kaptcha.image.height">45</prop>  
                        <prop key="kaptcha.textproducer.font.size">45</prop>  
                        <prop key="kaptcha.session.key">code</prop>  
                        <prop key="kaptcha.textproducer.char.length">4</prop>  
                        <prop key="kaptcha.textproducer.font.names">宋体,楷体,微软雅黑</prop>  
                    </props>  
                </constructor-arg>  
            </bean>  
        </property>  
    </bean>

kaptcha可配置项（网上寻找的）：

[java] view plain copy

1. kaptcha.border  是否有边框  默认为true  我们可以自己设置yes，no    
2. kaptcha.border.color   边框颜色   默认为Color.BLACK    
3. kaptcha.border.thickness  边框粗细度  默认为1    
4. kaptcha.producer.impl   验证码生成器  默认为DefaultKaptcha    
5. kaptcha.textproducer.impl   验证码文本生成器  默认为DefaultTextCreator    
6. kaptcha.textproducer.char.string   验证码文本字符内容范围  默认为abcde2345678gfynmnpwx    
7. kaptcha.textproducer.char.length   验证码文本字符长度  默认为5    
8. 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)    
9. kaptcha.textproducer.font.size   验证码文本字符大小  默认为40    
10. kaptcha.textproducer.font.color  验证码文本字符颜色  默认为Color.BLACK    
11. kaptcha.textproducer.char.space  验证码文本字符间距  默认为2    
12. kaptcha.noise.impl    验证码噪点生成对象  默认为DefaultNoise    
13. kaptcha.noise.color   验证码噪点颜色   默认为Color.BLACK    
14. kaptcha.obscurificator.impl   验证码样式引擎  默认为WaterRipple    
15. kaptcha.word.impl   验证码文本字符渲染   默认为DefaultWordRenderer    
16. kaptcha.background.impl   验证码背景生成器   默认为DefaultBackground    
17. kaptcha.background.clear.from   验证码背景颜色渐进   默认为Color.LIGHT_GRAY    
18. kaptcha.background.clear.to   验证码背景颜色渐进   默认为Color.WHITE    
19. kaptcha.image.width   验证码图片宽度  默认为200    
20. kaptcha.image.height  验证码图片高度  默认为50  

3：JSP页面

<script type="text/JavaScript">

        $(function(){  //生成验证码         
            $('#kaptchaImage').click(function () {  
            $(this).hide().attr('src', '${pageContext.request.contextPath}/captcha/getCaptchaImage.htm?' + Math.floor(Math.random()*100) ).fadeIn(); });      
        });   

        window.onbeforeunload = function(){  
            //关闭窗口时自动退出  
            if(event.clientX>360&&event.clientY<0||event.altKey){     
                alert(parent.document.location);  
            }  
        };  
    
        function changeCode() {  //刷新
              $('#kaptchaImage').hide().attr('src', '${pageContext.request.contextPath}/captcha/getCaptchaImage.htm?' + Math.floor(Math.random()*100) ).fadeIn();  
               /*  event.cancelBubble=true; */  
        }  

</script>

<div class="form-item login-name"> <span class="form-label login-form-label">验证码</span>
                  <input id="verifyCode" name="verifyCode" class="form-yz login_3" type="text">
                  <img src="${pageContext.request.contextPath}/captcha/getCaptchaImage.htm" id="kaptchaImage" style="cursor: pointer;width:80px;height:32px;" onclick="changeCode()" title="看不清，点击换一张">
                  <div style="clear:both;"></div>
                </div>

4：Java核心代码

/** 
 * 图片生成验证码
 * @author panliang 
 * 
 */  
@Controller  
@RequestMapping("/captcha")  
public class CaptchaController {  
      
    @Autowired  
    private Producer captchaProducer = null;  
  
    @RequestMapping(value="/getCaptchaImage.htm")  
    public ModelAndView getCaptchaImage(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;  
    }  
  
}  

5：提交表单时登录逻辑判断验证码是否正确

String kaptchaExpected = (String)request.getSession().getAttribute(com.google.code.kaptcha.Constants.KAPTCHA_SESSION_KEY); //验证码
        String verifyCode = request.getParameter("verifyCode")==null?"":request.getParameter("verifyCode").toString();//输入验证码

  再判断放在缓存里面的和输入框输入的是不是一样的/********