JSR 175: Metadata for Java in Public Review

from http://www.theserverside.com/news/thread.tss?thread_id=22269

The expert group for JSR 175 has released a public review draft of the Metadata Facility for the Java Programming Language spec.

Info from the details page

We believe there are several elements needed as part of this JSR:

- Definition of a Java programming language feature that allows medatadata information to be supplied for (at least) classes, interfaces, methods, and fields. This language extension will allow metadata to be recognized by development tools. It appears likely that it will be useful to allow attribute values to be associated with given metadata attributes.

      The exact syntax will need to be determined by the expert group. There appear to be a number of possibilities, including (but not limited to!) using a doc comment tag @meta or adding a new Java programming language keyword meta.

- Definition of a runtime delivery format for metadata and of runtime APIs so that tools and libraries can accesss metadata information at deployment time and at runtime.

- Definition of rules for the attribute namespace so as to avoid accidental collisions over the same attribute name. Details will be determined by the expert group, but it seems that a mechanism leveraging the class naming conventions might be useful.

This list is not meant to be exhaustive. For example, if it is determined that there is a need for the compiler to do some validity checking on metadata, we will need a mechanism for communicating restrictions on the use of a particular attribute (such as "The attribute com.acme.Remote may be used on methods, but not on classes, interfaces, or fields"). Metadata processing tools such as stub generators, however, are outside the scope of this JSR. The JSR is intended to enable such tools, but not to define them.

Download the public review draft

View the home page of JSR 175: A Metadata Facility for the Java Programming Language

This Public Review closes on 5 December 2003.

Does it match the expectations? Is what we are waiting for?