What causes the "FAIL - Deploy Upload Failed, Exception: null" error message in tomcat?

Question

What causes the "FAIL - Deploy Upload Failed, Exception: null" error message in tomcat?

I'm trying to deploy a war to tomcat from the manager but when I try to upload I get the error

FAIL - Deploy Upload Failed, Exception: null

with the following error message in the log

SEVERE: HTMLManager: FAIL - Deploy Upload Failed, Exception: null
java.lang.NullPointerException
    at org.apache.commons.fileupload.DefaultFileItem.write(DefaultFileItem.java:442)
    at org.apache.catalina.manager.HTMLManagerServlet.doPost(HTMLManagerServlet.java:211)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:524)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:869)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:664)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684)
    at java.lang.Thread.run(Thread.java:619)

Answer 1

I think that you have a problem with the access rights - unless Tomcat is running as root, which I thing would be even worse. If not, the Tomcat user will need rw access to its webapp dir (and should own it) in order to unpack anything.