Re: [sca-j] JAVA-98: Simplified proposed direction for resolution

[David Booz <booz@us.ibm.com>]

See below please.

Dave Booz
STSM, BPM and SCA Architecture
Co-Chair OASIS SCA-Policy TC and SCA-J TC
"Distributed objects first, then world hunger"
Poughkeepsie, NY (845)-435-6093 or 8-295-6093
e-mail:booz@us.ibm.com

Simon Nash <oasis@cjnash.com> wrote on 04/07/2009 06:39:36 PM:

> [image removed]
>
> [sca-j] JAVA-98: Simplified proposed direction for resolution
>
> Simon Nash
>
> to:
>
> OASIS Java
>
> 04/07/2009 06:40 PM
>
> Here is a simplified version of the proposal with the following changes
> from the previous proposal:
>   1. Disallow intents on implementation methods.
>   2. Allow implementation intents on interface methods and interfaces.
>
> A) Specific intent annotations can appear together with @Requires
>     on the same Java program element.  If they do, the annotations
>     contributed by specific intent annotations are merged with those
>     contributed by @Requires, following the policy rules for merging
>     intents at the same hierarchy level.
>
>     Intents can be applied to a Java class or Java interface used as
>     an SCA service interface, a method of a Java class or Java interface
>     used as an SCA service interface, a Java class used as an
>     SCA service implementation, a Java reference, a Java interface for
>     a reference, or a method of a Java interface for a reference.  It is
>     an error to apply an intent to a method of a Java class not used as
>     an SCA service interface.

So then is the following legal? I thought we were disallowing intents
on implementation methods, but your words above seem to allow this case.

<component name="TestClient">
<implementation.java class="test.ASM_0002_Client"/>
<service name="TestInvocation">
<interface.java interface="test.ASM_0002_Client"/>
</service>
</component>

package test;
public class ASM_0002_Client {
@Confidentiality
public void method1(int x) {}
}

>
> B) The effective intents for a method of an SCA interface defined by
>     <interface.java> are computed by the following algorithm:
>     1. Use the rules in A) above to find the intents for the method

I see where this is specified in A).

>        and the intents for its declaring class or interface.

I don't see where this is specified in A).  The only thing A) talks
about is what to do for same method attachment.

>     2. Use the policy rules for merging intents within a structural
>        hierarchy to merge the intents found in step 1 above, with the
>        method at the lower level and the method's declaring class or
>        interface at the higher level.

I'm just not following this....what is a method at the lower level?
I thought B) was resolving intents at the interface level esp. since
intents can't be attached to implementation methods.  An example
might help me.

>     These rules are applied to the methods of a Java implementation
>     class or Java interface used to define an SCA service interface,
>     and to the methods of the Java interface for a reference.
>
> C) The effective intents for each method of an SCA service are computed
>     by applying the rules in the Policy specification to the intropected
>     component type implied by the rules in D) below, using the effective
>     intent computation rules in B) above.
>
> D) The componentType introspection rules for intents are as follows:
>     1. Intents on the service implementation class are placed on the
>        <implementation.java> element in the componentType.

Do you mean class level attached intents?

>     2. For all SCA services defined using Java interfaces, intents on
>        the service implementation class are placed on the corresponding
>        <service> elements in the componentType.

So, impl class level attachment results in the intents being placed on both
the implementation element and the service element?

>     3. Intents on Java references are placed on the corresponding
>        <reference> elements in the componentType.
>
>    Simon

I really think we need a few examples to work through this. I'd offer
a few but I'm not sure if I have the right mental model yet.

>
>
> ---------------------------------------------------------------------
> To unsubscribe from this mail list, you must leave the OASIS TC that
> generates this mail.  Follow this link to all your TCs in OASIS at:
> https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php
>