java - Wicket 中多文件上传的 FileNotFoundException

Question

我们使用的是 Wicket 6+，并且在 FileUpload.writeTo(file) 上出现奇怪的错误。它仅发生在某些类型的文件(docx、xlsx、java)上，并且仅以一种形式发生。同样的代码可以在其他地方很好地附加文件。有什么帮助吗？谢谢。

HTML:

<div wicket:id="filesInput"/>

Java:

add(new org.apache.wicket.markup.html.form.upload.MultiFileUploadField("filesInput", 
                    new PropertyModel<Collection<FileUpload>>(this, "uploads"), 5));

fileUpload.writeTo(file) 行抛出错误；当从表单 onSubmit 调用时。

private void writeToFile(FileUpload fileUpload, Attachment attachment) {
    if (fileUpload == null) {
        return;
    }
    File file = AttachmentUtils.getFile(attachment, jtracHome);
    try {
        fileUpload.writeTo(file);
    }
    catch (Exception e) {
        throw new RuntimeException(e);
    }
}

错误日志:

2013-05-03 12:57:23,731 [http-bio-8084-exec-9] ERROR [org.apache.wicket.DefaultExceptionMapper] -  Unexpected error occurred
org.apache.wicket.WicketRuntimeException: Method onFormSubmitted of interface org.apache.wicket.markup.html.form.IFormSubmitListener targeted at [SpaceItemViewForm [Component id = form]] on component [SpaceItemViewForm [Component id = form]] threw an exception
    at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:268)
    at org.apache.wicket.RequestListenerInterface.invoke(RequestListenerInterface.java:216)
    at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.invokeListener(ListenerInterfaceRequestHandler.java:240)
    at org.apache.wicket.core.request.handler.ListenerInterfaceRequestHandler.respond(ListenerInterfaceRequestHandler.java:226)
    at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:840)
    at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
    at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:254)
    at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:211)
    at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:282)
    at org.apache.wicket.protocol.http.WicketFilter.processRequestCycle(WicketFilter.java:244)
    at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:188)
    at org.apache.wicket.protocol.http.WicketFilter.doFilter(WicketFilter.java:267)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
    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:225)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:999)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:565)
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:307)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.apache.wicket.RequestListenerInterface.internalInvoke(RequestListenerInterface.java:258)
    ... 31 more
Caused by: java.lang.RuntimeException: java.io.FileNotFoundException: C:\Users\aeb\AppData\Roaming\NetBeans\7.2.1\apache-tomcat-7.0.27.0_base\temp\upload_9108b655_6177_4450_8e82_a767f101dd40_1997755963.tmp (The system cannot find the file specified)
    at info.jtrac.JtracImpl.writeToFile(JtracImpl.java:405)
    at info.jtrac.JtracImpl.storeScopeOfWork(JtracImpl.java:2053)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:301)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:198)
    at $Proxy11.storeScopeOfWork(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:301)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
    at $Proxy12.storeScopeOfWork(Unknown Source)
    at info.jtrac.wicket.SpaceItemViewFormPanel$SpaceItemViewForm.onSubmit(SpaceItemViewFormPanel.java:433)
    at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1246)
    at org.apache.wicket.markup.html.form.Form$9.component(Form.java:1240)
    at org.apache.wicket.util.visit.Visits.visitPostOrderHelper(Visits.java:274)
    at org.apache.wicket.util.visit.Visits.visitPostOrder(Visits.java:245)
    at org.apache.wicket.markup.html.form.Form.delegateSubmit(Form.java:1239)
    at org.apache.wicket.markup.html.form.Form.process(Form.java:921)
    at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:767)
    at org.apache.wicket.markup.html.form.Form.onFormSubmitted(Form.java:700)
    ... 36 more
Caused by: java.io.FileNotFoundException: C:\Users\aib\AppData\Roaming\NetBeans\7.2.1\apache-tomcat-7.0.27.0_base\temp\upload_9108b655_6177_4450_8e82_a767f101dd40_1997755963.tmp (The system cannot find the file specified)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:138)
    at org.apache.wicket.util.upload.DiskFileItem.write(DiskFileItem.java:439)
    at org.apache.wicket.markup.html.form.upload.FileUpload.writeTo(FileUpload.java:234)
    at info.jtrac.JtracImpl.writeToFile(JtracImpl.java:402)

Answer 1

所以这是异常发生的代码:

if (!outputFile.renameTo(file))
        {
            BufferedInputStream in = null;
            BufferedOutputStream out = null;
            try
            {
                in = new BufferedInputStream(new FileInputStream(outputFile));
                out = new BufferedOutputStream(new FileOutputStream(file));
                Streams.copy(in, out);
            }
            finally
            {
                IOUtils.closeQuietly(in);
                IOUtils.closeQuietly(out);
            }
        }

javadoc:

This method is only guaranteed to work once, the first time it is invoked for a particular item. This is because, in the event that the method renames a temporary file, that file will no longer be available to copy or rename again at a later time.

异常来自“outputFile”文件的打开 - 就好像它不再存在一样。 renameTo 是否可能成功对文件执行某些操作，但 renameTo 方法仍然返回 false？你能在那里设置一个断点并看看发生了什么吗？也许不知何故你确实调用了两次？

来自 renameTo 的 javadoc:

Many aspects of the behavior of this method are inherently platform-dependent: The rename operation might not be able to move a file from one filesystem to another, it might not be atomic, and it might not succeed if a file with the destination abstract pathname already exists. The return value should always be checked to make sure that the rename operation was successful.