ProjectSearcher.java

package org.ggp.base.util.reflection;

import java.lang.reflect.Modifier;

import org.ggp.base.apps.kiosk.GameCanvas;
import org.ggp.base.player.gamer.Gamer;
import org.reflections.Reflections;

import com.google.common.base.Objects;
import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;

public class ProjectSearcher {
    private ProjectSearcher() {
    }

    public static void main(String[] args)
    {
        System.out.println(GAMERS);
        System.out.println(GAME_CANVASES);
    }

    private static final Reflections REFLECTIONS = new Reflections();

    public static final LoadedClasses<Gamer> GAMERS = new LoadedClasses<Gamer>(Gamer.class);
    public static final LoadedClasses<GameCanvas> GAME_CANVASES = new LoadedClasses<GameCanvas>(GameCanvas.class);

    public static final <T> ImmutableSet<Class<? extends T>> getAllClassesThatAre(Class<T> klass) {
        return new LoadedClasses<T>(klass).getConcreteClasses();
    }

    public static class LoadedClasses<T> {
        private static Predicate<Class<?>> IS_CONCRETE_CLASS = new Predicate<Class<?>>() {
            @Override
            public boolean apply(Class<?> klass) {
                return !Modifier.isAbstract(klass.getModifiers());
            }
        };

        private final Class<T> interfaceClass;
        private final ImmutableSet<Class<? extends T>> allClasses;
        private final ImmutableSet<Class<? extends T>> concreteClasses;

        private LoadedClasses(Class<T> interfaceClass) {
            this.interfaceClass = interfaceClass;
            this.allClasses = ImmutableSet.copyOf(REFLECTIONS.getSubTypesOf(interfaceClass));
            this.concreteClasses = ImmutableSet.copyOf(Sets.filter(allClasses, IS_CONCRETE_CLASS));
        }

        public Class<T> getInterfaceClass() {
            return interfaceClass;
        }

        public ImmutableSet<Class<? extends T>> getConcreteClasses() {
            return concreteClasses;
        }

        public ImmutableSet<Class<? extends T>> getAllClasses() {
            return allClasses;
        }

        @Override
        public String toString() {
            return Objects.toStringHelper(this)
                    .add("allClasses", allClasses)
                    .add("interfaceClass", interfaceClass)
                    .add("concreteClasses", concreteClasses)
                    .toString();
        }
    }
}