ERROR org.zkoss.zk.au.http.AuUploader - Failed to upload java.lang.NullPointerException: null

asked 2017-06-22 08:23:53 +0800

anilkumar99850 gravatar image anilkumar99850
11 1

ERROR org.zkoss.zk.au.http.AuUploader (Fileupload specifically not working in Linux Environment)


I have a problem while uploading file(which is more than 5 MB) in ZK by using “UploadEvent”. Its not working when I deploy application on linux server,but same code is working in loacal windows machine. There is no clue where the file upload fails it give the error as fallows.

web - 2017-06-22 15:35:22,100 [http-bio-7070-exec-5] ERROR org.zkoss.zk.au.http. AuUploader - Failed to upload java.lang.NullPointerException: null at org.zkoss.zk.au.http.AuUploader.service(AuUploader.java:115) ~[zk-7.0 .2.jar:7.0.2] at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java :459) [zk-7.0.2.jar:7.0.2] at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.jav a:494) [zk-7.0.2.jar:7.0.2] at javax.servlet.http.HttpServlet.service(HttpServlet.java:650) [servlet -api.jar:na] at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) [servlet -api.jar:na] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl icationFilterChain.java:303) [catalina.jar:7.0.63]

And MyZK Configuration File


Could some one help me on this exception please.

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1 Answer

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answered 2020-07-02 18:25:15 +0800

valeriobozz gravatar image valeriobozz
31 1

updated 2020-07-02 18:33:29 +0800

Have you a frontend webserver in front of your application (Apache Proxy)? Have you a slow connection?

If yes, maybe your application is receiving a malformed request because of inefficient communication between the two layers.

If this may be your case, we fixed applying this solution:


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Asked: 2017-06-22 08:23:53 +0800

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Last updated: Jul 02

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