struts2 自定义拦截器 不调用
如题，这是配置：

  <constant name="struts.enable.DynamicMethodInvocation" value="true" />

    <constant name="struts.devMode" value="true" />



    <package name="test" namespace="/" extends="struts-default">

    	<interceptors>

        	<interceptor name="a" class="ysgw/dave/myInterceptor/MyInterceptor"/>

        </interceptors>



        <default-action-ref name="test" />



        <global-results>

            <result name="error">/error.jsp</result>

        </global-results>



        <global-exception-mappings>

            <exception-mapping exception="java.lang.Exception" result="error"/>

        </global-exception-mappings>

        

        

        

        <action name="test">

            <interceptor-ref name="a"/>

            <interceptor-ref name="defaultStack"/>

            <result> /TestInterceptor.jsp</result>

        </action>

        

     </package> 

这是拦截器代码：

package ysgw.dave.myInterceptor;



import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.AbstractInterceptor;



public class MyInterceptor extends AbstractInterceptor{



	/**

	 * 

	 */

	private static final long serialVersionUID = 1L;





	@Override

	public String intercept(ActionInvocation invocation) throws Exception {

		long startTime = System.nanoTime();

		System.out.println("start time : " + startTime);

		String result = invocation.invoke();

		long endTime = System.nanoTime();

		System.out.println("end time : " + endTime);

		System.out.println("time : " + (endTime - startTime));

		

		return result;

	}

	

}

------解决方案--------------------
ysgw/dave/myInterceptor/MyInterceptor->ysgw.dave.myInterceptor.MyInterceptor