On 2/8/12 3:48 PM, Richard S. Hall wrote:
On 2/8/12 15:19 , Irving Cordova wrote:
Hi,
I am currently using a 3rd party component in a small project of
mine. This
component tries to dynamically load resources from a given URL, it does
this by trying several extensions for a base name, and returns
success when
it finds a resource that matches the base name and extension. For this
dynamic loading it depends on URL.openStream(). If openStream returns
FileNotFoundException it continues looking, but if openStream returns
IOException it assumes something is wrong with the resource, stops
looking
and throws an exception. This works fine in a non OSGi environment, and
also inside equinox, however it does not work inside Felix. Felix
throws a
IOException with the message: "Resource does not exist" instead of a
FileNotFoundException. Compare the stack traces:
Felix:
java.io.IOException: Resource does not exist:
bundle://93.0:1/resource/myresource.stg
at
org.apache.felix.framework.URLHandlersBundleURLConnection.<init>(URLHandlersBundleURLConnection.java:131)
at
org.apache.felix.framework.URLHandlersBundleStreamHandler.openConnection(URLHandlersBundleStreamHandler.java:64)
at java.net.URL.openConnection(URL.java:945)
at java.net.URL.openStream(URL.java:1010)
Equinox:
java.io.FileNotFoundException: /resource/myresource.stg
at
org.eclipse.osgi.framework.internal.protocol.bundleresource.Handler.findBundleEntry(Handler.java:51)
at
org.eclipse.osgi.framework.internal.core.BundleResourceHandler.openConnection(BundleResourceHandler.java:175)
at java.net.URL.openConnection(URL.java:945)
at java.net.URL.openStream(URL.java:1010)
Shouldn't the appropriate exception be FileNotFoundException ?
It doesn't necessarily seem like this is more appropriate. We are not
talking about a file in the file system, we are talking about a
resource in a JAR file. I see nothing in the API JavaDoc that
indicates that openConnection() should through a
FileNotFoundException, nor specifically should it through such an
exception to indicate a less severe error type than IOException.
s/through/throw/g
Sorry about that.
So, I guess the question is, do should we modify the framework to
always throw FileNotFoundException when it cannot find the resource to
participate in this non-standard protocol?
It's not clear to me that it makes sense to me, but you could open a
feature request in JIRA and assign it to the framework component for
consideration.
I talked with Thomas Watson (Equinox lead) about this and he agreed that
IOException is completely reasonable. He said that Equinox throws FNFE
because that is what URLClassLoader used to do when Equinox used that as
its class loader, when they switched to a custom class loader a user
complained when they started throwing IOExceptions so they switched back
to FNFEs.
I still suggest you open up a feature request issue for the framework so
we can track it. Thanks.
-> richard
Thanks.
-> richard
Regards,
Irving Cordova
http://irvingc.com
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