Question

我在加载特定页面时偶尔会遇到以下异常：

java.lang.NoClassDefFoundError: Could not initialize class com.app.item.search.SearchResultPanel
        at com.app.item.search.SearchResultPage.initialize(SearchResultPage.java:86)
        at com.app.core.layout.BasePage.onInitialize(BasePage.java:147)
        at org.apache.wicket.Component.fireInitialize(Component.java:864)
        at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:955)
        at org.apache.wicket.Page.isPageStateless(Page.java:464)
        at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.getPageInfo(AbstractBookmarkableMapper.java:447                                                                                                                  )
        at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.mapHandler(AbstractBookmarkableMapper.java:391)
        at org.apache.wicket.request.mapper.mount.UnmountedMapperAdapter.mapHandler(UnmountedMapperAdapter.java:61)
        at org.apache.wicket.request.mapper.mount.MountMapper.mapHandler(MountMapper.java:145)
        at org.apache.wicket.request.mapper.CompoundRequestMapper.mapHandler(CompoundRequestMapper.java:215)
        at org.apache.wicket.request.cycle.RequestCycle.mapUrlFor(RequestCycle.java:429)
        at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:271)
        at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:175)
        at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:862)
        at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
        at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:261)
        at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:218)
        at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:289)
        --- CUT ---
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
        at java.lang.Thread.run(Thread.java:619)

问题通过重新启动tomcat（可能是2,3,4或5次）来解决，只有在我部署到开发/集成环境时才会发生。在我的开发VM上它从未发生过。它只影响几页/面板（总是它们）。

SearchResultPanel是一个简单的类，它扩展了wicket Panel类。

在catalina.out上我看到搜索结果是从Lucene加载的，但是当它显示页面时，我收到了上面的异常和来自wicket / tomcat的404页面。

SearchResultPanel的构造函数：

public SearchResultPanel(String id, final SearchResult resultList)

生成异常的行（SearchResultPage：86）：

SearchResultPanel resultPanel = new SearchResultPanel("searchResults",
                results);

SearchResultPanel位于应用程序的WEB-INF文件夹中：

# locate SearchResultPanel
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$1.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$2.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$3.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$4.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$5.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$6.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$7.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$8.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$ItemFragment$1.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$ItemFragment$2.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$ItemFragment$3.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$ItemFragment.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel$SortImageModel.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel.class
/var/lib/tomcat7/webapps/app/WEB-INF/classes/com/app/item/search/SearchResultPanel.html

使用：

Wicket：6.14.0
Apache Tomcat / 7.0.26

您能否请进一步告知我如何调试此类加载问题？

非常感谢！

Tomcat + Wicket零星的NoClassDefFoundError

0 个答案: