ArrayIndexOutOfBoundsException in ResourceBundle.getBundle(String)in JDK 6&7

[Heiko Wagner]

On 5/11/2011 5:39 AM, Alan Bateman wrote:
> On 04/11/2011 12:03, Heiko Wagner wrote:
>> Hi Tom, thanks for your reply. I am using JNI in a different,propably
>> never
>> designed to be used that way, kind of scenario. I use JNI to bring
>> Java to a
>> legacy Smalltalk based product[1].
>>
>> The Smalltalk code does directly invoke the JNI calls from its own
>> Smalltalk
>> VM main thread. So the Java VM is not aware of the calling thread and
>> has no
>> call stack information. Currently, I am using
>> ClassLoader.getSystemClassLoader(), which perfectly works for me. I
>> have no
>> idea if this makes sense in gerneal, but for me a
>> MissingResourceBundleException in my use case, would be what I propably
>> would have expected, instead of a ArrayIndexOutOfBoundsException, so
>> maybe a
>> additional size check on the call stack array size would make sense.
>>
> The thread must be known to the VM as otherwise you wouldn't have a
> JNIEnv and wouldn't be able to call the method (so I'll bet the thread
> is attaching via AttachCurrentThread somewhere).
>
> As to the ArrayIndexOutOfBoundsException, that does seem to be a bug as
> I assume that getClassContext is returning an array of one element
> corresponding to the caller frame (getBundle in this case).

>There are a handful of places in the JDK where this kind of stack-based
>check is used and the assumption is always that there is a "client" Java
>caller in the stack. Given this kind of code is unaware of the context
>in which it is called in general, what exception would you throw if you
>find there is no Java client caller? In the current case the specs for
>getBundle state that it is the equivalent of calling the
>classloader-taking form with the expression
>this.getClass().getClassLoader(). But in the current case there is no
>this, no current class and no current classloader - so what exception do
>you throw? "new RuntimeException("Expected Java caller not found")?

>I don't think throwing MissingResourceBundleException is the right way
>to go here because it hides the mis-use of this API.

>David

Hi, David. I agree that it is a mis-use use of the API. I would be
perfectly happy, if the error message would more obviously state this fact.
In my opinion the ArrayIndexOutOfBoundsException does not properly reflect
this.

If you take Class.forName(String) as an example, which also tries to
determine the classloader of the caller, when being used this way,
it throws a ClassNotFoundException, also hiding the API mis-use.
So the patter here looks to me like:
No Java caller -> No classloader -> No class -> ClassNotFoundException

So my initial idea followed that bevaviour:
No Java caller -> No classloader -> No ResourceBundle ->
MissingResourceBundleException

Don't get me wrong I don't want to state, that the JRE is something wrong.
I just wanted to state that it would be nice, if the JRE could give
developers, that
are, just like me, not aware of the fact that some methods just can't be
invoked directly
from JNI, a better hint to that fact.

Regards,
Heiko