RFR 8129215: com.sun.jmx.mbeanserver.Introspector may provide results inconsistent with the JavaBeans Introspector

[Jaroslav Bachorik]

On 19.6.2015 15:50, Daniel Fuchs wrote:
> Hi guys,
>
> I believe there's a difference between Attribute names, and navigation
> into complex attributes.
>
> At the MBean level attribute names are case sensitive.
> At Attribute level (= within an attribute) I believe it follows
> the Bean patterns (like for instance the mapping of complex
> MXBean attribute types to CompositeData).
> A property of an Attribute (as in MemoryUsage.used) is not itself
> an Attribute - but a bean property.
>
> A careful reading of the JMX 1.4 spec should hopefully make it possible
> to validate that ;-)

Also, some JCK tests are relying on the Attribute properties being 
treated as JavaBean properties. These were, in fact, the ones triggering 
this issue when run without j.b.Introspector being available.

So, if I understand it correctly, with my fix the implementation will be 
in agreement with the spec again even when j.b.Introspector is not 
available.

-JB-

>
> cheers,
>
> -- daniel
>
> On 19/06/15 14:05, Jaroslav Bachorik wrote:
>> On 19.6.2015 13:44, Alan Bateman wrote:
>>>
>>> On 19/06/2015 12:38, Jaroslav Bachorik wrote:
>>>>
>>>> Both the j.b.Introspector.getReadMethod() and the
>>>> SimpleIntrospector.getReadMethod() are used only from
>>>> c.s.j.m.Introspector.elementFromComplex() method and only to resolve
>>>> the getter for a complex attribute.
>>>>
>>>> So, any change in the SimpleIntrospector will not affect the rest of
>>>> the JMX system.
>>>>
>>>> Given this statement in the Monitoring javadocs
>>>> (https://docs.oracle.com/javase/8/docs/api/javax/management/monitor/package-summary.html)
>>>>
>>>>
>>>>
>>>>
>>>> "If the above rules do not produce a value, and if introspection, as
>>>> if by calling Introspector.getBeanInfo, for the class of v
>>>> (v.getClass()) identifies a property with the name e, then x is the
>>>> result of reading the property value."
>>>>
>>>> I would strongly propose to adjust the SimpleIntrospector to closely
>>>> follow the j.b.Introspector functionality.
>>>>
>>> I added the SimpleIntrospector and also adjusted the above wording in
>>> the monitor package description to make it possible to have JMX in a
>>> compact Profile of Java SE that didn't have java.beans.
>>>
>>> The intention was that the SimpleIntrospector works like the beans
>>> Introspector. So I agree this is the right thing to do but we should
>>> create a bug for the issue that Daniel brings up.
>>
>> I'm not sure there is an issue here. The monitoring api attribute names
>> seem to be governed by different rules than the MBean attribute names.
>> This change relates to the monitoring api only and brings the
>> implementation up to the what is specified in the javadoc.
>>
>> -JB-
>>
>>>
>>> -Alan.
>>
>