<!----------------struts.xml  ----------------->

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

     <action name="product_*" class="productAction" method="{1}">

     </action>

  </package>

<!---------------- applicationContext.xml  ----------------->

 <!-- 配置Action的类 -->

    <bean id="productAction" class="action.ProductAction" scope="prototype">

     <!-- 手动注入Service -->

     <property name="priductService" ref="productService"></property>

   </bean> 

   <!-- 配置业务层的类 -->

    <bean id="productService" class="service.ProductService">

       <property name="productDao" ref="productDao"/>

    </bean>  

  <!-- 配置Dao类 -->

   <bean id="productDao" class="dao.ProductDao"> </bean>

<!----------------------------jsp----------------------->

<s:form action="product_save" method="post" namespace="/" theme="simple">

       <table border="1" width="400">

            <tr>

               <td>商品名称</td>

                <td><s:textfield name="pname"/></td>

            </tr>

           <tr>

               <td>商品价格</td>

                <td><s:textfield name="price"></s:textfield></td>

            </tr>

             <tr>

              <td colspan="2"><input type="submit" value="添加"/></td>

            </tr>

       </table>

  </s:form>

<!-----------------------exection----------------->

org.apache.jasper.JasperException: java.lang.NullPointerException
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:96)

root cause

java.lang.NullPointerException
org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:827)
org.apache.struts2.components.UIBean.end(UIBean.java:535)
org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
org.apache.jsp.addProduct_jsp._jspx_meth_s_005ftextfield_005f0(addProduct_jsp.java:177)
org.apache.jsp.addProduct_jsp._jspx_meth_s_005fform_005f0(addProduct_jsp.java:133)
org.apache.jsp.addProduct_jsp._jspService(addProduct_jsp.java:80)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:96)