解决ServletUrlRenderer WARN警告：
[org.apache.struts2.components.ServletUrlRenderer:http-8000-1:45] - No configuration found for the specified action: 'sums' in namespace: '/example'. Form action defaulting to 'action' attribute's literal value.
struts.xml配置：
Java代码
1.<package name="Library" namespace="/example" extends="struts-default">
2. <action name="sum" class="example.HelloWorld">
3. <result name="positive">positive.jsp</result>
4. <result name="nagative">nagative.jsp</result>
5. </action>
6.</package>
2.jsp页面
Java代码
1.<s:form action="sum" namespace="/example" >
2. <s:textfield name="counta" label=" 操作数1"/>
3. <s:textfield name="countb" label=" 操作数2" />
4. <s:submit value="代数和" />
5.</s:form>
namespace,action确定