<Beans Dev> JEP review request: BeanInfo Generation Improvements

[sergey malenkov]

Hello,

Could you please review the attached JEP?

Thanks,
SAM
-------------- next part --------------
Title: BeanInfo Generation Improvements
Author: Sergey Malenkov
Organization: Oracle
Created: 2014/4/1
Type: Feature
State: Draft
Exposure: Open
Component: client/beans
Scope: JDK
RFE: 4763438, 4058433
Discussion: beans-dev at openjdk.java.net
Start: 2014/Q1
Effort: S
Duration: S
Template: 1.0
Reviewed-by:
Endorsed-by:
Funded-by: Oracle Client-libs Team

Summary
-------
Replace the @beaninfo tags, which are processed at compile-time
to generate BeanInfo classes, with the corresponding annotations,
which are used to generate BeanInfo at runtime.

Motivation
----------
This work be done to make the modularization of the client library easier.
It also simplifies the creation of the custom BeanInfo by users.

Description
-----------
Now all BeanInfo are automatically generated at runtime,
but several Swing classes generates BeanInfo classes
from the @beaninfo tags at compile-time.
Here we propose to replace the @beaninfo tags with the following annotations
and add some improvements to the existing introspection algorithm.

    public @interface Bean {
        String description() default "";
        String defaultProperty() default "";
        String defaultEventSet() default "";
    }
    public @interface Property {
        boolean bound() default true;
        boolean expert() default false;
        boolean hidden() default false;
        boolean preferred() default false;
        boolean visualUpdate() default false;
        String description() default "";
        String[] enumerationValues() default {};
    }
    public @interface SwingContainer {
        boolean value() default true;
        String delegate() default "";
    }

These annotations will set the corresponding feature attributes
during the BeanInfo generation at runtime.
It will allow to remove automatically generated classes
and prepare the client library for the modularization.
Also, it will be useful for users to describe the BeanInfo in the class
instead of creating a separate BeanInfo class for that bean class.
Some feature attributes are described here:
https://sites.google.com/site/malenkov/java/071004

Testing
-------
Need to verify that the new introspection algorithm behaves as expected.
Need to verify that the new introspection algorithm doesn't break backward
compatibility in unexpected ways (or need to ensure that cases in which
backward compatibility is not preserved are sufficiently rare).

Risks and Assumptions
---------------------
The primary risk of this change is that any change affecting introspection
has the potential for backwards incompatibility.
But we expect the the risk is very low.

Dependences
-----------
Now it is hard to prepare the client library for modularization.

Impact
------
  - Compatibility:
    The introspection of several properties may differ with new introspection algorithm,
    but we do not expect any backward incompatibility.
  - Security:
    We should do the security audit, because the reflection is used.
  - Performance/scalability:
    We do not expect the performance degradation.
    The refactoring of the introspection algorithm could improve the performance.
  - User experience:
    We should create an user guide about
    how to use new annotations instead of custom BeanInfo classes.
  - Documentation:
    The new annotations provide additional javadoc.