forName() ... ClassNotFoundException

[scottdanzig]

Hi all,

I don't have the stack trace handy, but I've been fretting over an
exception I've been getting and hopefully I can provide enough
information:

There are two classes in the same jar file. One calls the other by
finding its name in a config file and using
java.lang.Class.forName(String) to load it. This works fine when run
in the Eclipse debugger as separate class files, but when run from
within a jar, via a Windows service, the forName call gives a
ClassNotFoundException. We checked the jar, and the target class does
exist, with the correct package name before it and no typos (it did
work in the debugger).

I saw forName is making a call to a method called doPrivileged().. am
I having some sort of permission issue even though it's two classes in
the same jar? What other things might be wrong?

Thanks in advance for your attention and hopefully what help you can
offer

- Scott

 

[Brandon McCombs]

Hi all,

I don't have the stack trace handy, but I've been fretting over an
exception I've been getting and hopefully I can provide enough
information:

There are two classes in the same jar file. One calls the other by
finding its name in a config file and using
java.lang.Class.forName(String) to load it. This works fine when run
in the Eclipse debugger as separate class files, but when run from
within a jar, via a Windows service, the forName call gives a
ClassNotFoundException. We checked the jar, and the target class does
exist, with the correct package name before it and no typos (it did
work in the debugger).

I saw forName is making a call to a method called doPrivileged().. am
I having some sort of permission issue even though it's two classes in
the same jar? What other things might be wrong?

Thanks in advance for your attention and hopefully what help you can
offer

- Scott

What is the class path as defined in the jar file's MANIFEST.MF file? Is
the class that is being loaded within that class path? What is the value
of the String argument to forName()? Is it the fully qualified name of
the class file you want loaded?

 

[Andrew Thompson]

scottdanzig wrote:
..

I don't have the stack trace handy, but I've been fretting ..

Rather than fret, why not get back to us when you
*do* 'have a stacktrace handy'?

--
Andrew Thompson
http://www.athompson.info/andrew/

Message posted via JavaKB.com
http://www.javakb.com/Uwe/Forums.aspx/java-general/200704/1

 

[Chris Uppal]

This works fine when run
in the Eclipse debugger as separate class files, but when run from
within a jar, via a Windows service, the forName call gives a
ClassNotFoundException.

A mistake to [try to] generalise directly from the very artificial environment
provided by Eclipse to the almost equally unnatural environment in which a
Windows service runs. Try it running as a standalone process using only the
command-line tools and the -jar argument.

-- chris

 

[scottdanzig]

Hi all,

I don't have the stack trace handy, but I've been fretting over an
exception I've been getting and hopefully I can provide enough
information:

There are two classes in the same jar file. One calls the other by
finding its name in a config file and using
java.lang.Class.forName(String) to load it. This works fine when run
in the Eclipse debugger as separate class files, but when run from
within a jar, via a Windows service, the forName call gives a
ClassNotFoundException. We checked the jar, and the target class does
exist, with the correct package name before it and no typos (it did
work in the debugger).

I saw forName is making a call to a method called doPrivileged().. am
I having some sort of permission issue even though it's two classes in
the same jar? What other things might be wrong?

Thanks in advance for your attention and hopefully what help you can
offer

- Scott

Fixed. The issue was, the application, when run via a Windows service
was launched through a wrapper that didn't include a jar which the
class in question needed to instantiate. The actual stack trace was
being masked from me, with the way the application's logging was set
up. Sorry.

- Scott

 

[xterra]

I really interested in the solution because I have the same problem (Eclipse, plugin for database connection - working in standalone and not working with ClassNotFound exception when used from application). Please provide some ideas (altough it was many years ago).