原因：

默认web.xml配置

 <filter>
        <filter-name>struts2</filter-name>
        <filter-class>
            org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
        </filter-class>
    </filter>

    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

站点所有请求都要经过struts2过滤器，即CKFinder相关请求也会被struts2拦截，导致请求没有经过CKFinder配置的servlet。

 <servlet>
        <servlet-name>ConnectorServlet</servlet-name>
        <servlet-class>com.ckfinder.connector.ConnectorServlet</servlet-class>
        <init-param>
            <param-name>XMLConfig</param-name>
            <param-value>/WEB-INF/ckfinder.xml</param-value>
        </init-param>
        <init-param>
            <param-name>debug</param-name>
            <param-value>false</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>ConnectorServlet</servlet-name>
        <url-pattern>/ckfinder2.4/core/connector/java/connector.java </url-pattern>
    </servlet-mapping>

解决办法：

自己实现struts2过滤器，判断是否CKFinderde
请求，如果是则放行，否则默认struts2的方式继续往下走。部分代码如下：

import org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter;

public class MyStrutsInterceptor extends StrutsPrepareAndExecuteFilter {
    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        String URI = request.getRequestURI();

        String[] ckfarr = URI.split("/ckfinder2.4/core/connector/java/*/");
        int arrayLen = ckfarr.length;
        if (arrayLen >= 2) {
            chain.doFilter(req, res);
        } else {
            super.doFilter(req, res, chain);
        }

    }

}

原文链接：http://www.iyuze.cn/article/485.html