Java APIs

Hi all,

i've got a Problem using RMI. Following exception is thrown:

java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.net.MalformedURLException: no protocol: xxx.

Cause of this error is an URLClassLoader of an external application using my JDBC-Driver which connects to my server via RMI. The URLClassLoader (got by class.getClassLoader()) contains at first position in the array an URL representing a jarfile by absoulte path, containing whitespaces. This URL seems to be set by the extern application to the classpath with these whitespaces. I do not know where and how to change it.
I thought of a solution of this problem to manipulate ClassLoader to replace all containing white spaces in the URLs with the correct syntax for URLs: %20.
In the first try, i used system-property "java.rmi.server.codebase" to set the correct codebase with replaced spaces. This seems not to work. The codebase-property seems to be used by RMIClassLoader (i short look to the code shows, that codebase-property is only used if the current classloader is also a system classloader?).
Second try was to create an own URLClassLoader with correct URL-Strings. But i do not know how to use it for RMI. Using my correct URLClassLoader for my class instance with following code:

final URL[] urLs = ((URLClassLoader) cl.getClassLoader()).getURLs();
final URL[] newUrls = new URL[urLs.length];
int i = 0;
for (final URL url : urLs) {
try {
newUrls[i] = new URL(url.toExternalForm().replace(" ", "%20"));
} catch (final MalformedURLException e) {
LOG.error("An error occurred, cause is: " + e.getMessage(), e);
}
i++;
}
loader = new URLClassLoader(newUrls, originalClassLoader);
final Class<?> clazz = loader.loadClass("MyDriver");
final Object instance = clazz.newInstance();

does not work. Do you know how i can use this classloader instead of the original classloader to solve my problem with white spaces in URLs?

Many thanks in advance!