Struts中应用Tiles框架的问题

在Struts中应用Tiles框架，利用ForwardAction进行跳转，但出现Path index-definition does not start with a "/" character的问题。此处的index-definition 是在tiles-defs.xml中定义的，作为struts-config中Action配置的parameter属性的值。
上述方法引用自网络，但运行中会出现 java.lang.IllegalArgumentException: Path index-definition does not start with a "/" character异常。
代码如下：

  <action-mappings>
    <action path="/index"
		type="org.apache.struts.actions.ForwardAction"
		parameter="index-definition">
	</action>
  </action-mappings>

<definition name="index-definition" path="/layout.jsp">
<put name="sidebar" value="sidebar.jsp"/>
<put name="header" value="header.jsp"/>
<put name="content" value="indexContent.jsp"/>
<put name="footer" value="footer.jsp"/>
</definition>

严重: Servlet.service() for servlet action threw exception
java.lang.IllegalArgumentException: Path index-definition does not start with a "/" character
	at org.apache.catalina.core.ApplicationContext.getRequestDispatcher(ApplicationContext.java:379)
	at org.apache.catalina.core.ApplicationContextFacade.getRequestDispatcher(ApplicationContextFacade.java:195)
	at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:107)
	at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
	at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
	at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
	at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
	at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
	at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
	at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
	at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
	at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
	at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
	at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
	at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
	at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
	at java.lang.Thread.run(Thread.java:619)