java - 创建 Apache Tiles 简单应用程序时出现异常

Question

我正在尝试创建我的第一个 Tiles 网页。我正在使用 this tutorial在完成所有配置后，我得到了这个异常(exception):

java.lang.NullPointerException
    at org.apache.tiles.access.TilesAccess.getContainer(TilesAccess.java:124)
    at org.apache.tiles.access.TilesAccess.getContainer(TilesAccess.java:107)
    at org.apache.tiles.access.TilesAccess.getCurrentContainer(TilesAccess.java:174)
    at org.apache.tiles.template.InsertDefinitionModel.execute(InsertDefinitionModel.java:95)
    at org.apache.tiles.jsp.taglib.InsertDefinitionTag.doTag(InsertDefinitionTag.java:254)
    at org.apache.jsp.menu.menu_jsp._jspx_meth_tiles_005finsertDefinition_005f0(menu_jsp.java:92)
    at org.apache.jsp.menu.menu_jsp._jspService(menu_jsp.java:65)
    at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

我创建了 tiles-defs.xml 并将所有配置添加到我的 web.xml。

Answer 1

我走同样的教程，发现缺少配置。将此添加到 web.xml:

<listener>
    <listener-class>org.apache.tiles.web.startup.simple.SimpleTilesListener</listener-class>
</listener>

此监听器将跟踪应用程序启动并使用默认方式配置磁贴(主要磁贴配置应仅在此处:/WEB-INF/tiles.xml)，只要在默认配置中硬编码即可.