On 1/11/2011 7:35 AM, Ivan wrote:
I agree with Forrest that those code logic might need to be updated.
From the codes fragment below of UtilLoader
In the loadClass method, it will first try the
ProviderLocator.loadClass, but what ProviderLocation.loadClass expect
is an interface class name, like javax.rmi.CORBA.Util.
So those codes in the static block of Util, it should first try to
load it from ProviderLocator with service provider interface.
Comments ?
I think the static code in the Util class should be something like:
// Initialize delegate
String delegateName = (String)AccessController.doPrivileged(new
GetSystemPropertyAction("javax.rmi.CORBA.UtilClass",defaultDelegate));
try {
// this is a little bit recursive, but this will use the full
default search order for locating
// this.
delegate = (UtilDelegate)UtilLoader.loadServiceClass(delegateName,
Delegate.class).newInstance();
}catch (Throwable e) {
org.omg.CORBA.INITIALIZE ex =new org.omg.CORBA.INITIALIZE("Can not
create Util delegate:"+delegateName);
ex.initCause(e);
throw ex;
}
Where UtilLoader.loadServiceClass() is a method that functions like
UtilLoader.loadClass(), but takes both an interface class name that is
used to qualify the lookup.
Rick
-->
static public Class loadClass(String name, String codebase,
ClassLoader loader)
throws ClassNotFoundException {
Class result = null;
try {
return ProviderLocator.loadClass(name, null, loader);
} catch (ClassNotFoundException e) {
//skip
}
ClassLoader stackLoader = null;
ClassLoader thisLoader = UtilLoader.class.getClassLoader();
Class[] stack = _secman.getClassContext();
for (int i = 1; i < stack.length; i++) {
ClassLoader testLoader = stack[i].getClassLoader();
if (testLoader != null && testLoader != thisLoader)
{
stackLoader = thisLoader;
break;
}
}
......
<---
2011/1/11 Rick McGuire <[email protected] <mailto:[email protected]>>
On 1/11/2011 4:46 AM, Forrest Xia wrote:
Hi,
When I debug a corba related application, I managed to trace
into a piece of yoko code like this:
public class Util {
private static UtilDelegate delegate = null;
private static final String defaultDelegate =
"org.apache.yoko.rmi.impl.UtilImpl";
// To hide the default constructor we should implement
empty private constructor
private Util() {}
static {
// Initialize delegate
String delegateName =
(String)AccessController.doPrivileged(new
GetSystemPropertyAction("javax.rmi.CORBA.UtilClass",
defaultDelegate));
try {
// this is a little bit recursive, but this will
use the full default search order for locating
// this.
delegate = (UtilDelegate)Util.loadClass(delegateName, null,
null).newInstance();
} catch (Throwable e) {
org.omg.CORBA.INITIALIZE ex = new
org.omg.CORBA.INITIALIZE("Can not create Util delegate:
"+delegateName);
ex.initCause(e);
throw ex;
}
}
...
According to another code in
ProviderRegistryImpl$SPIRegistry(the id's value is the
delegateName variable as highlighted above), while the
registry hashmap's key is "javax.rmi.CORBA.UtilClass", that
will lead CNF exception.
private synchronized BundleProviderLoader getLoader(String id) {
// synchronize on the registry instance
if (registry != null) {
log.fine("registry: " + registry);
// return the first match, if any
List<BundleProviderLoader> list = registry.get(id);
if (list != null && !list.isEmpty()) {
return list.get(0);
}
}
// no match here
return null;
}
So my question is should we change the Util code to pass the
interface class name to load class? Please advise.
I'm not sure I understand the question. The target class in
question here is a concrete delegate instance, so I don't
understand why you think an interface is needed here. The loading
in question here is just for the delegate class that is used for
the rmi util class.
In any event, you cannot change any of the method signatures for
the javax.rmi.CORBA.Util class. That is a standard API class and
you can't add that.
I think I understand what you wish to do here, and I'd recommend
adding a loadServiceClass() method to the UtilLoader class and
change the initializer in Util to use that directly rather than
recursively calling Util.loadClass().
Rick
Forrest
--
Ivan
