We have a webstart swing application running on our multiple remote desktop servers for a lot of customers. Suddenly, on one of our servers the customers started getting a java.lang.NoClassDefFoundError. Not on startup, the applications starts up fine, but when doing specific tasks, eg sending a mail through our software, it popups up in the console like this:
java.lang.NoClassDefFoundError: pos/MailSenderInterface
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
......
Caused by: java.lang.ClassNotFoundException: pos.MailSenderInterface
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 56 more
The problem is, this only happens on ONE of our servers. On all the other servers the webstart application runs just fine! But on this single terminal server, I get the error, even though the java version is the same, and the link to the jnlp-file is the same. I have of course tried deleting temporary internet files in the java control panel, to no avail. I then started toying around a bit, and found out something very strange. Our customers start the application from an icon pointing to a batch-file in c:\drift This batchfile only contains the following:
@start javaws http://ourserver/ourapplication.jnlp
Typing the link outside the batch-file gives the same error. Then I typed cd .. so that my current path was c:\ instead of c:\drift and started javaws from there. And surprise, no errors! I then tried cd drift again and the error occured again. I have tried this many times now, with the same result. So somehow the path from WHERE I start javaws have something to say for if I get the NoClassDefFoundError or not. But neither c:\ or c:\drift contains any .jar-files (although subdirectories may). I am very perplexed by this. What on earth is wrong? Our java version is 1.7.0_67
Aha! The path c:\drift\ actually had a directory "pos" from a couple of years back, with an old version of MailSender.class but with no MailSenderInterface.class Deleting this directory solved the problem. :-) (Remember that the error was about a missing pos/MailSenderInterface) Apparently the newest javaws in java 1.7.0_67 tries to load classes from a subdirectory of the place where you started javaws if such a directory is found, instead of loading the files from the correctly downloaded jar-files.