• 驗證碼采用一個博客上的驗證碼 點擊跳轉
• 采用action的形式獲取驗證碼，并把驗證碼存入到shiro管理的session中

public void getGifCode(HttpServletResponse response,HttpServletRequest request){
    try {
        response.setHeader("Pragma", "No-cache");  
        response.setHeader("Cache-Control", "no-cache");  
        response.setDateHeader("Expires", 0);  
        response.setContentType("image/gif");  
        /**
         * gif格式動畫驗證碼
         * 寬，高，位數。
         */
        Captcha captcha = new GifCaptcha(146,42,4);
        //輸出
        ServletOutputStream out = response.getOutputStream();
        captcha.out(out);
        out.flush();
       //存入Shiro會話session  
        System.out.println( captcha.text().toLowerCase());
        TokenManager.setVal2Session(VerifyCodeUtils.V_CODE, captcha.text().toLowerCase());  
    } catch (Exception e) {
        LoggerUtils.fmtError(getClass(),e, "獲取驗證碼異常：%s",e.getMessage());
    }
}

• 驗證碼驗證的 Shiro 過濾器

public class JCaptchaValidateFilter extends AccessControlFilter{

    /**
     * 是否開啟驗證碼驗證   默認true
     */
    private boolean jcaptchaEbabled = true;

    /**
     * 前臺提交的驗證碼參數名
     */
    private String jcaptchaParam = "jcaptchaCode";

    /**
     * 驗證失敗后存儲到的屬性名
     */
    private String failureKeyAttribute = "shiroLoginFailure";

    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object o) throws Exception {
        //1、設置驗證碼是否開啟屬性，頁面可以根據該屬性來決定是否顯示驗證碼
        request.setAttribute("jcaptchaEbabled", jcaptchaEbabled);

        HttpServletRequest httpRequest = WebUtils.toHttp(request);

        //2、判斷驗證碼是否禁用 或不是表單提交（允許訪問）
        if (jcaptchaEbabled == false || !"post".equalsIgnoreCase(httpRequest.getMethod())) {
            return true;
        }

        //表單提交，校驗驗證碼的正確性
        String storedCode = getSubject(request, response).getSession().getAttribute(Constatns.VERIFYCODE).toString();
        String currentCode = httpRequest.getParameter(jcaptchaParam);

        return StringUtils.equalsIgnoreCase(storedCode, currentCode);
    }
    @Override
    protected boolean onAccessDenied(ServletRequest request, ServletResponse servletResponse) throws Exception {
        //如果驗證碼失敗了，存儲失敗 key 屬性
        request.setAttribute(failureKeyAttribute, "jCaptcha.error");
        return true;
    }
    public String getFailureKeyAttribute() {
        return failureKeyAttribute;
    }
    public void setFailureKeyAttribute(String failureKeyAttribute) {
        this.failureKeyAttribute = failureKeyAttribute;
    }
    public String getJcaptchaParam() {
        return jcaptchaParam;
    }
    public void setJcaptchaParam(String jcaptchaParam) {
        this.jcaptchaParam = jcaptchaParam;
    }
    public boolean isJcaptchaEbabled() {
        return jcaptchaEbabled;
    }
    public void setJcaptchaEbabled(boolean jcaptchaEbabled) {
        this.jcaptchaEbabled = jcaptchaEbabled;
    }
}

• MyFormAuthenticationFilter ，表單提交時，先驗證驗證碼，如果驗證成功再走登錄流程

用于驗證碼驗證的 Shiro 攔截器在用于身份認證的攔截器之前運行；但是如果驗證碼驗證攔截器失敗了，就不需要進行身份認證攔截器流程了；所以需要修改下如FormAuthenticationFilter 身份認證攔截器，當驗證碼驗證失敗時不再走身份認證攔截器。

public class MyFormAuthenticationFilter extends FormAuthenticationFilter {
    @Override
    protected boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception {
        if(request.getAttribute(getFailureKeyAttribute()) != null) {
            return true;
        }
        return super.onAccessDenied(request, response);
    }
}

• 配置文件的配置

<!-- 基于form表單的身份驗證過濾器 帶有驗證碼的過濾-->
<bean id="myformAuthenticationFilter" class="com.nanc.core.shiro.filter.MyFormAuthenticationFilter">
    <property name="usernameParam" value="username"/>
    <property name="passwordParam" value="password"/>
    <property name="rememberMeParam" value="rememberMe"/>
    <property name="loginUrl" value="/login"/>
    <property name="failureKeyAttribute" value="shiroLoginFailure"/>
</bean>

<!-- 驗證碼的過濾器 -->
<bean id="jCaptchaFilter" class="com.nanc.core.shiro.filter.JCaptchaValidateFilter">
    <property name="failureKeyAttribute" value="shiroLoginFailure"/>
    <property name="jcaptchaParam" value="jcaptchaCode"/><!-- 頁面的參數名-->
    <property name="jcaptchaEbabled" value="true"/>
</bean>

<!-- Shiro的Web過濾器 -->
<bean id="shiroFilter" class="org.apache.shiro.spring.web.ShiroFilterFactoryBean">
    <property name="securityManager" ref="securityManager"/>
    <property name="loginUrl" value="/login"/>
    <property name="filters">
        <map>
            <!--<entry key="authc" value-ref="formAuthenticationFilter"/>-->
            <entry key="authc" value-ref="myformAuthenticationFilter"/>
            <entry key="jcaptcha" value-ref="jCaptchaFilter"/>
            <entry key="sysUser" value-ref="sysUserFilter"/>
            <entry key="kickout" value-ref="kickoutFilter"/>
            <!--添加ssl支持-->
            <!--<entry key="ssl" value-ref="sslFilter"/>-->
            <!-- 結束ssl支持-->
        </map>
    </property>
    <property name="filterChainDefinitions">
        <value>
            /login=jcaptcha,authc
            /loginDialog=authc
            /logout=logout
            /authenticated=authc
            /dwz_jui/**=anon
            /common/**=anon
            /**=kickout,user,sysUser
        </value>
    </property>
</bean>