java.util.zip.ZipException: Not in GZIP format exception when launching java web start app with jnlp

Question

I am launching java web start app with jnlp. The jnlp is generated dynamically using jsp. I have set jnlp.packEnabled to true in jnlp file. All the jars are repacked, signed and packed with java's pack200. using below ant script.

    <echo message="Repacking jars" />
            <apply executable="pack200" parallel="false">
                <arg value="--repack" />
                <fileset dir="${build.dir}" includes="*.jar" />
            </apply>

            <echo message="Signing jars" />
            <signjar destdir="${build.dir}" keyPass="test" keyStore="${project.root}/testKeys" storePass="test" alias="t">
                <fileset dir="${build.dir}" includes="*.jar" />
            </signjar>

            <echo message="Pack Signed jars" />
            <apply executable="pack200" parallel="false" dest="${build.dir}">
                <arg value="--modification-time=latest"/>
                <arg value="--deflate-hint=true"/>
                <arg value="--segment-limit=-1"/>
                <fileset dir="${build.dir}" includes="*.jar" />
                <targetfile />
                <srcfile />
                <mapper type="glob" from="*" to="*.pack.gz" />
            </apply>


java.util.zip.ZipException: Not in GZIP format
    at java.util.zip.GZIPInputStream.readHeader(Unknown Source)
    at java.util.zip.GZIPInputStream.<init>(Unknown Source)
    at java.util.zip.GZIPInputStream.<init>(Unknown Source)
    at com.sun.deploy.net.HttpDownloadHelper.download(Unknown Source)
    at com.sun.deploy.cache.Cache.downloadResourceToTempFile(Unknown Source)
    at com.sun.deploy.cache.Cache.downloadResourceToCache(Unknown Source)
    at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
    at com.sun.deploy.net.DownloadEngine.downloadResource(Unknown Source)
    at com.sun.deploy.cache.ResourceProviderImpl.getResource(Unknown Source)
    at com.sun.deploy.cache.ResourceProviderImpl.getResource(Unknown Source)
    at com.sun.javaws.LaunchDownload$DownloadTask.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

on web start application launch its giving aboveerror. Please suggest how to solve this error. And when i try to view *.pack.gz file with WINRAR, i could see only one file with .pack extension,i cant open it with WINRAR says it is a damaged file.

EDIT 1 :File is not damaged. I am able unpack it manually using unpack200 and run from command prompt without any issues. Exception is shown only when the file is downloaded from jnlp. I doubt the dynamic generation of jnlp from jsp is causing the issue. Below is my jsp code. Could you please suggest me a solution to get rid of this exception when unpacking from dynamically generated jnlp file.

<%@ page contentType="application/x-java-jnlp-file" language="java"%>
<%@page session="false" %>
<%
response.setContentType("application/x-java-jnlp-file");%>
<!-- JNLP File -->
<?xml version="1.0" encoding="utf-8"?>
<jnlp spec="1.0+">
<information>
<title>Service</title>
<vendor>Service</vendor> </information> 
<security> <all-permissions /> </security> 
<resources> 
<jfx:javafx-runtime version="2.2.4+"
    href="http://javadl.sun.com/webapps/download/GetFile/javafx-latest/windows-i586/javafx2.jnlp" />
</resources> 
<resources> 
<!-- Application Resources --> 
    <property name="jnlp.packEnabled" value="true"/>
    <j2se version="1.7+" /> 
    <jar href="Test.jar" main="true"/> 
</resources> 
<application-desc
    name="main" main-class="com.test.Main" width="300"
    height="300">
    <argument><%= request.getParameter("userId")%></argument>
    <argument><%= request.getParameter("userName")%></argument>
</application-desc> 
<update check="always" policy="always" />
</jnlp>

So that is the problem. The file either is damaged at the source, or gets damaged during the download. Impossible to say how with no access to the environment you're in, for all I know the harddisk of the server is broken. — Gimby

foch foch · Accepted Answer · 2013-12-11T19:16:27

I suggest you try tool unpack200 (it's in the JDK) to see if your .pack.gz is correct. If not, it might be a hardware issue.

java.util.zip.ZipException: Not in GZIP format exception when launching java web start app with jnlp

1 Answers