Unable to deploy App more than once, ClassLoader Issues

Answer 1

Here is a way to solve your problem.
try to use
Runtime.getRuntime().load(absolute_library_path);
However, make a copy of the library you tried to load and name it uniquely such
as
append the current miliseconds.
After completed loading the library into the Runtime, new File(new_library_path).delete();
or you can try to use deleteOnExit() (createdTempFile instead).
"Bob H" <[email protected]> wrote:
>
I am working on a project that relies on the SAP Java Connector (JCO).
This "connector"
consists of a JAR containing some Java classes, and some native platform
libraries
(i.e. DLLs for Windows). The problem is I can only deploy the application
once
on a running WL Server 7.0 node. If after the first deployment I remove
the application
(via the WL server console) and try to redeploy, deployment works fine,
but the
JVM will not be able to load the SAP JCO stuff... if fails on calling
the native
library with an ExceptionInInitializerError:
java.lang.ExceptionInInitializerError: JCO.classInitialize(): Could not
load middleware
layer 'com.sap.mw.jco.rfc.MiddlewareRFC' Native Library C:\WINDOWS\system32\sapjcorfc.dll
already loaded in another class loader
Based on this error message it appears that the class loader created
for the previous
deployment still exists (even though the application is no longer deployed),
and
therefore still has a hold on the native library (which apparently can't
support
multiple processes).
What I have to do is stop the server, start back up and then redeploy.
This is
a very exhausing ordeal during development, and also leads to a not-very-flexible
situation for production.
Does anyone know if there a way to terminate this other classloader instance
while
the server is running?
Thanks,
Bob