“在Wicket 7中打开多个选项卡时，无法从文件上载中的字节[]”反序列化对象

Question

我们有一个大的wicket应用程序，有一个恼人的bug。我们有一个带有文件上传字段的表单，并且在大多数情况下它工作正常。它失败的唯一时间是用户打开多个浏览器选项卡。然后我们得到以下异常（每打开一个额外的标签一次）：

java.lang.RuntimeException: Could not deserialize object from byte[]
    at org.apache.wicket.serialize.java.JavaSerializer.deserialize(JavaSerializer.java:143)
    at org.apache.wicket.pageStore.AbstractPageStore.deserializePage(AbstractPageStore.java:152)
    at org.apache.wicket.pageStore.AbstractCachingPageStore.getPage(AbstractCachingPageStore.java:67)
    at com.sw.system4.ui.RemovablePageManagerProvider$1.getPage(RemovablePageManagerProvider.java:51)
    at org.apache.wicket.page.PageStoreManager$SessionEntry.getPage(PageStoreManager.java:231)
    at org.apache.wicket.page.PageStoreManager$PersistentRequestAdapter.getPage(PageStoreManager.java:393)
    at org.apache.wicket.page.AbstractPageManager.getPage(AbstractPageManager.java:82)
    at org.apache.wicket.page.PageManagerDecorator.getPage(PageManagerDecorator.java:50)
    at org.apache.wicket.page.PageAccessSynchronizer$2.getPage(PageAccessSynchronizer.java:246)
    at org.apache.wicket.DefaultMapperContext.getPageInstance(DefaultMapperContext.java:113)
    at org.apache.wicket.core.request.handler.PageProvider.getStoredPage(PageProvider.java:299)
    at org.apache.wicket.core.request.handler.PageProvider.isNewPageInstance(PageProvider.java:211)
    at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.checkExpiration(AbstractBookmarkableMapper.java:335)
    at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.processListener(AbstractBookmarkableMapper.java:309)
    at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.mapRequest(AbstractBookmarkableMapper.java:369)
    at org.apache.wicket.request.mapper.CompoundRequestMapper.mapRequest(CompoundRequestMapper.java:147)
    at org.apache.wicket.request.cycle.RequestCycle.resolveRequestHandler(RequestCycle.java:189)
    at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:219)
    at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:293)
    at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:261)
    at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:203)
    at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:284)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625)
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2517)
    at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2506)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.io.FileNotFoundException: C:\Program Files\Apache Software Foundation\Tomcat 7.0\temp\upload_d17f019a_9bfa_48c5_bc2c_6fc0bf74d233_00004982.tmp (The system cannot find the file specified)
    at java.io.FileInputStream.open0(Native Method)
    at java.io.FileInputStream.open(Unknown Source)
    at java.io.FileInputStream.(Unknown Source)
    at org.apache.commons.fileupload.disk.DiskFileItem.readObject(DiskFileItem.java:684)
    at sun.reflect.GeneratedMethodAccessor4472.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at java.io.ObjectStreamClass.invokeReadObject(Unknown Source)
    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source)

    ... lots of read lines snipped

    at java.io.ObjectInputStream.readSerialData(Unknown Source)
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readObject(Unknown Source)
    at org.apache.wicket.serialize.java.JavaSerializer.deserialize(JavaSerializer.java:126)

FileUploadField采用的形式是较大页面的一部分，因此用户选择一个文件并使用ajax提交按钮上传，然后再继续。

Form<?> uploadForm = new Form<Void>( "uploadForm" );
uploadForm.setMultiPart( true );
add( uploadForm );

IModel<List<FileUpload>> filesModel = Model.ofList( new ArrayList<>() );

uploadForm.add( new FileUploadField( "uploadField", filesModel) );

uploadForm.add( new AjaxBeforeSubmitLink( "loadLink" ) {

  private static final long serialVersionUID = 1L;

  @Override
  protected void onSubmit( AjaxRequestTarget target, Form<?> form ) {
    List<? extends FileUpload> files = filesModel.getObject();

    if ( l_files != null && !l_files.isEmpty() ) {
      callEntryModel.getObject().getVendorQuoteData().getFileUploads().addAll( files );
    }

    target.add( getUploadedFilesLabel() );
    target.add( getClearFilesLink() );

    onUpdateContractQuoteData( target );
  }
});

上传面板是使用wicket扩展的BreadCrumbPanels的“breadcrumb”样式页面的一部分。上传部分位于面板上，然后由面包屑中的下一个面板替换。当它们尝试执行导致错误发生的ajax调用的任何操作时，它位于该面板上。

据我所知，客户端请求有某种散列函数来定义要加载的临时文件的名称，这对于不同的选项卡是不同的？有没有其他人有这个问题，我似乎无法在任何地方找到它的任何引用。

我们使用的是Java 8 / Wicket 7.10

提前致谢

Answer 1

看来你在页面中保留了对FileItem对象的引用。

Wicket尝试从页面存储中反序列化页面，并在此过程中尝试加载没有后备文件的org.apache.commons.fileupload.disk.DiskFileItem。

Wicket的FileUploadField有一个瞬态field - 一个List<FileUpload>。但由于它是瞬态的，它根本不会被序列化。后来当它的public List<FileUpload> getFileUploads()被称为这个字段将是null和Wicket将使用commons-fileupload API加载它again。

对我来说，似乎你的应用程序在某处保留了对DiskFileItem的引用，因此它被序列化/反序列化。

您可以使用Wicket IObjectChecker查找引用的位置。有关如何实现自定义检查器的灵感，请参阅SessionChecker和DifferentPageChecker。