最近做一個web項目中有上傳文件的功能，已經寫出並在本地和部署到服務器上測試了好幾個文件上傳都沒問題（我用的是tomcat）。部署上服務器，上傳圖片時有的圖片大就回在tomcat日志報如下錯誤：
Unable to parse request
org.apache.commons.fileupload.FileUploadBase$IOFileUploadException: Processing of multipart/form-data request failed. null
at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:367) [commons-fileupload-1.2.1.jar:1.2.1]
at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.parseRequest(JakartaMultiPartRequest.java:189) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.processUpload(JakartaMultiPartRequest.java:127) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest.parse(JakartaMultiPartRequest.java:92) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper.<init>(MultiPartRequestWrapper.java:81) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.Dispatcher.wrapRequest(Dispatcher.java:796) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.ng.PrepareOperations.wrapRequest(PrepareOperations.java:134) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91) [struts2-core-2.3.15.1.jar:2.3.15.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243) [catalina.jar:7.0.35]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210) [catalina.jar:7.0.35]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222) [catalina.jar:7.0.35]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123) [catalina.jar:7.0.35]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472) [catalina.jar:7.0.35]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) [catalina.jar:7.0.35]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99) [catalina.jar:7.0.35]
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936) [catalina.jar:7.0.35]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118) [catalina.jar:7.0.35]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407) [catalina.jar:7.0.35]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004) [tomcat-coyote.jar:7.0.35]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589) [tomcat-coyote.jar:7.0.35]
at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:1822) [tomcat-coyote.jar:7.0.35]
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886) [na:1.6.0_13]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908) [na:1.6.0_13]
at java.lang.Thread.run(Thread.java:619) [na:1.6.0_13]
Caused by: java.io.IOException
at org.apache.coyote.http11.InternalAprInputBuffer.fill(InternalAprInputBuffer.java:612) [tomcat-coyote.jar:7.0.35]
at org.apache.coyote.http11.InternalAprInputBuffer$SocketInputBuffer.doRead(InternalAprInputBuffer.java:642) [tomcat-coyote.jar:7.0.35]
at org.apache.coyote.http11.filters.IdentityInputFilter.doRead(IdentityInputFilter.java:124) [tomcat-coyote.jar:7.0.35]
at org.apache.coyote.http11.InternalAprInputBuffer.doRead(InternalAprInputBuffer.java:534) [tomcat-coyote.jar:7.0.35]
at org.apache.coyote.Request.doRead(Request.java:422) [tomcat-coyote.jar:7.0.35]
at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:290) [catalina.jar:7.0.35]
at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:431) [tomcat-coyote.jar:7.0.35]
at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:315) [catalina.jar:7.0.35]
at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:200) [catalina.jar:7.0.35]
at org.apache.commons.fileupload.MultipartStream$ItemInputStream.makeAvailable(MultipartStream.java:977) [commons-fileupload-1.2.1.jar:1.2.1]
at org.apache.commons.fileupload.MultipartStream$ItemInputStream.read(MultipartStream.java:887) [commons-fileupload-1.2.1.jar:1.2.1]
at java.io.InputStream.read(InputStream.java:85) [na:1.6.0_13]
at org.apache.commons.fileupload.util.Streams.copy(Streams.java:94) [commons-fileupload-1.2.1.jar:1.2.1]
at org.apache.commons.fileupload.util.Streams.copy(Streams.java:64) [commons-fileupload-1.2.1.jar:1.2.1]
at org.apache.commons.fileupload.FileUploadBase.parseRequest(FileUploadBase.java:362) [commons-fileupload-1.2.1.jar:1.2.1]
... 23 common frames omitted
然后在百度和谷歌上各種搜索，大多數認為是超時而斷開連接。對於解決辦法一般給的不夠全面，現綜合給出如下：
（1）首先，上傳頁面上面的 form 標簽要設enctype="multipart/form-data" 參數
（2）修改tomcat配置文件server.xml，找到類似於下面配置:
<Connector port="8086" maxHttpHeaderSize="8192"
maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
enableLookups="false" redirectPort="8443" acceptCount="100"
connectionTimeout="20000" disableUploadTimeout="true" />
將上面的參數disableUploadTimeout值改為false即可。
（3）上邊（1）是我的程序中已經設置的，修改了（2）所述的配置后依然不能運行，后來又修改了tomcat配置文件server.xml中的另外一處：
<Connector executor="tomcatThreadPool"
port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" /> 也在里邊加入了disableUploadTimeout="false"一句。
用了以上方法仍然不能解決，后來想到可能是服務器外加了防火牆或者限制了上傳文件的大小之類的，聯系網絡中心進行相關設置進行設置即可。
資料參考：
http://www.cnblogs.com/qingxinblog/p/3437169.html