Re: [ve-dev] using JEM to introspect/reflect bean

[Rich Kulp <richkulp@xxxxxxxxxx>]

Hi,

To use JEM, you need to have a project
that is a Java project. It does introspection on a per Java project basis.

Note: The BeanInfo classes still are
marked internal, but that is because they haven't been made API yet. They
are stable and not likely to change very much except to be renamed to API
classes sometime in the future.

To use:

... To setup for  a project do
this once per session to initialize the BeanInfo process:

        IProject
biProject = JavaProjectUtil.getProject("name of project");
        BeaninfoNature
nature = BeaninfoNature.getRuntime(biProject);
        ResourceSet
javarset = nature.getResourceSet();

... Now the javarset is a ResourceSet
used for JEM for the project. So to actually do introspection:

        JavaClass
jclass = JavaRefFactory.eINSTANCE.reflectType("fully-qualified classname",
javarset);

From the jclass you can accessors to
get the information you need. For example jclass.getAllProperties() returns
all of the EStructuralFeatures that are BeanInfo properties.

There are two ways to access the actual
BeanInfo such as PropertyDecorator (which corresponds to java.beans.PropertyDescriptor).
The first is to get it from the EStructuralFeature. In that case you would
do (Utilities is org.eclipse.jem.internal.beaninfo.core.Utilities):

        PropertyDecorator
prop = Utilities.getPropertyDecorator(estructuralfeature);

Or to get all of the PropertyDecorators
for a class:

        Iterator
propertyItr = Utilities.getPropertiesIterator(jclass.getAllProperties());

and then use the iterator. It will return
PropertyDecorator's from the iterator.

On JavaRefFactory there are various
types of "reflectType" methods. You can choose which fits for
you. The same goes for the Utilities. There are various methods that do
different things to help you out.

Thanks,
Rich