What makes a Java Applet Jar Invalid?

Hello,
I have an issue with an applet. The issue has occured from more than one computer. The applet was last deployed in April. It was working from then.What can we look for that would invalidate the ability to read a jar file?


network: Downloading resource: https://[path and file name removed for privacy].jar
      Content-Length: -1
      Content-Encoding: null
java.io.IOException: Invalid jar file
      at com.sun.deploy.net.DownloadEngine.getJarFileWithoutCache(Unknown Source)
      at com.sun.deploy.net.DownloadEngine.getJarFileWithoutCache(Unknown Source)
      at com.sun.deploy.net.DownloadEngine.downloadJarWithoutCache(Unknown Source)
      at sun.plugin.PluginURLJarFileCallBack$2.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.plugin.PluginURLJarFileCallBack.retrieve(Unknown Source)
      at sun.net.www.protocol.jar.URLJarFile.retrieve(Unknown Source)
      at sun.net.www.protocol.jar.URLJarFile.getJarFile(Unknown Source)
      at sun.net.www.protocol.jar.JarFileFactory.get(Unknown Source)
      at sun.net.www.protocol.jar.JarURLConnection.connect(Unknown Source)
      at sun.plugin.net.protocol.jar.CachedJarURLConnection.connect(Unknown Source)
      at sun.plugin.net.protocol.jar.CachedJarURLConnection.getJarFileInternal(Unknown Source)
      at sun.plugin.net.protocol.jar.CachedJarURLConnection.getJarFile(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath$JarLoader.getJarFile(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath$JarLoader.access$1000(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath$JarLoader$1.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at com.sun.deploy.security.DeployURLClassPath$JarLoader.ensureOpen(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath$JarLoader.<init>(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath$3.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at com.sun.deploy.security.DeployURLClassPath.getLoader(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath.getLoader(Unknown Source)
      at com.sun.deploy.security.DeployURLClassPath.getResource(Unknown Source)
      at sun.plugin2.applet.Plugin2ClassLoader$2.run(Unknown Source)
      at java.security.AccessController.doPrivileged(Native Method)
      at sun.plugin2.applet.Plugin2ClassLoader.findClassHelper(Unknown Source)
      at sun.plugin2.applet.Applet2ClassLoader.findClass(Unknown Source)
      at sun.plugin2.applet.Plugin2ClassLoader.loadClass0(Unknown Source)
      at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
      at sun.plugin2.applet.Plugin2ClassLoader.loadClass(Unknown Source)
      at java.lang.ClassLoader.loadClass(Unknown Source)
      at sun.plugin2.applet.Plugin2ClassLoader.loadCode(Unknown Source)
      at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source)
      at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
jvmnjAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

CEHJCommented:
Last i heard, with current JREs, all applets must be signed now
0
mccarlIT Business Systems Analyst / Software DeveloperCommented:
Make sure that the JAR is being served properly too. Put the address (https://[path and file name removed for privacy].jar) into a normal browser address bar and make sure that is downloads the JAR file properly. Check that the downloaded jar file is correct.
0
jvmnjAuthor Commented:
Thanks mccarl.

I have done that it downloads and was able to view the files in a decompiler. I can confirm that the same jar file loads using the same client browser in 2 other deployed environments. What do you all think could be wrong with this environment?
0
Amazon Web Services

Are you thinking about creating an Amazon Web Services account for your business? Not sure where to start? In this course you’ll get an overview of the history of AWS and take a tour of their user interface.

CEHJCommented:
You could well have different runtimes - did you test them?
http://www.java.com/en/download/testjava.jsp
0
jvmnjAuthor Commented:
Thanks CEHJ.

But the the same applet jar, ran by the same user, from the same desktop (same jre) works in 2 environments. But in the quality environment it reads invalid jar. Any other thoughts?
0
jvmnjAuthor Commented:
Gonna close this. It turns out that we were accessing the application through our siteminder url. Siteminder was configured to ignore the path that the applet resides. So in order for the applet to load you have to use the direct websphere app url.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
jvmnjAuthor Commented:
I found the answer on my own
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Java

From novice to tech pro — start learning today.