help.! Java URLClassloader

[Sundar]

I have a requirement, I have to use the existing jar of websphere,
when my program is shipped. This program uses AdminClient of websphere
JMX. This has to run as a standalone. It installs an application using
JMX. What I require is to use URLCLassloader and load the adminclient,
objectname classes and use them. If I set classpath i am working fine,
but i do not have the luxury of that. Can I know how to use the
URLClassLoader.

A segment of my code looks like this.

AdminClient client;
Class createClass = loader.loadClass
("com.ibm.websphere.management.AdminClientFactory");

Class[] args=new Class[]{java.util.Properties.class};
Method create = createClass.getMethod("createAdminClient", args);
Object params[] = new Object[]{props};
Object obj= create.invoke((Object)"createAdminClient", params);
//works fine till this
client = (com.ibm.websphere.management.AdminClient)(obj); // casting
no success error.

String version = (client.getServerMBean()).getKeyProperty("version");
// this is my purpose.

Can anyone help me ? I am urgent schedule.

Thanks in advance,
sundar

 

[Anton Spaans]

Your 'loader' variable needs to be a URLClassLoader instance:

URL[] urlArray = ....;
loader = new URLClassLoader(urlArray);

Now the question is how to figure out the URLs in urlArray. I assume that
your AdminClientFactory class is available locally (i.e. you could use the
File object to get access to them), either in a directory on in a Java
Archive (.jar, etc.. file).
First, figure out the classpath you would have added if you had the luxury
of that ( as you put it ). Each item in that classpath (be sure you have
enough items to load your AdminClientFactory class and all the clasess it
needs, etc..) can be represented by a File object. Take these as examples:
"D:/MyProjects/ibm" for accessing
"com.ibm.websphere.management.AdminClientFactory" and
"D:/MyProjects/ibm/lib/ibm.jar" for the classes that are needed by it. Then:

URL[] urlArray = new URL[] {
new File("D:/MyProjects/ibm").toURL(),
new File().toURL("D:/MyProjects/ibm/lib/ibm.jar")
};


That should do it.
-- Anton.