Wildfly 8.0.2中的反射库

Question

I am trying to scan classes with Reflections library, if I add the Dynamic Web project to another project (plain Java one), I get the classes I want, but if run inside a @Startup bean, it is empty. Here is the code:

Reflections reflections = new Reflections(
    new ConfigurationBuilder().filterInputsBy(
        new FilterBuilder.Include(
            FilterBuilder.prefix("my.package")
        )
    ).setUrls(
        ClasspathHelper.forJavaClassPath()
    ).setScanners(
        new SubTypesScanner(false)
    )
);

Set<Class<? extends Object>> testClasses = reflections.getSubTypesOf(Object.class);

The tv,goopi should be changed to whatever package prefix used. the testClasses Set is empty.

If the same code is running in a different project referencing this one, no other change, then the Set is populated with all classes inside the package.

The Maven dependency for Reflections is:

<dependency>
    <groupId>org.reflections</groupId>
    <artifactId>reflections</artifactId>
    <version>0.9.9-RC1</version>
</dependency>

Wildfly 8.2.0. For now, I can save the file extracted in the external project and use the load function, but this will not be dynamic as it should be.

Answer 1

I struggled with this one for quite a while, it looks like due to the way it works, without getting the full java class path (makes it very heavy) you should load reflect a little bit later. This is mostly due to dynamic class creation during the EJB initialization phase, Startup beans included.

To load the full class path (from a startup bean) urls.addAll(ClasspathHelper.forJavaClassPath());

To make it cross JEE friendly, eg wild-fly, you need to reflect from a Servlet Context listener. For me the right place was in the constructor but a static field may work.

public class GuiceContext implements ServletContextListener
{

@Override
public void contextInitialized(ServletContextEvent servletContextEvent)
{
    ClasspathHelper.forWebInfLib(servletContextEvent.getServletContext());
  ClasspathHelper.forWebInfClasses(servletContextEvent.getServletContext());
}

Try and get your beans to initialize stand-alone without dependencies. You can also use a custom injector like Guice to push your beans. In this case you would use the GuiceServletContextListener class.

You are excluding direct exclusions of Object.class, this startup bean in this instance may not be loading due to this. new SubTypesScanner(false);

A complete library with org.reflections and guice directly implemented can be found at https://github.com/GedMarc/GuiceInjection