Mapping subclasses with Reflections

SubclassMapper.java

package com.rubenbermejo.gists

import com.reflections.Reflections

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
* A class for mapping all existing subtypes of a class within a package
*
*
* @author Rubén Bermejo Romero 2020
*/

public class SubclassMapper {
 
  private static final String CLASS_PACKAGE = "com.rubenbermejo.gists.myotherpackage";

  private static final Logger logger = LoggerFactory.getLogger(SubclassMapper.class);

  Reflections reflections = new Reflections(CLASS_PACKAGE);
  
  public Map<String, MyAbstractClass> mapClasses() throws RuntimeException {
        logger.debug("Looking for classes to map...");
        Set<Class<? extends MyAbstractClass>> abstractClasses = reflections.getSubTypesOf(MyAbstractClass.class);

        if (abstractClasses.isEmpty()) {
            logger.error("No classes have been found!");
            throw new RuntimeException("No classes were found!");
        }

        Map<String, MyAbstractClass> classMap = new HashMap<>();

        for (Class<? extends MyAbstractClass> abstractClass : abstractClasses) {
            try {
                logger.debug("Attempting to make instance of " + abstractClass.getName());
                MyAbstractClass classInstance = makeInstance(abstractClass);

                classMap.put(classInstance.getClass().getName(), classInstance);
                logger.debug(classInstance.getName() + " has been instantiated and mapped!");
            } catch (NoSuchMethodException |
                    InstantiationException |
                    IllegalAccessException |
                    InvocationTargetException e) {
                logger.error("Could not instantiate class - " + e.toString());

                throw new RuntimeException("Error while instantiating classes");
            }
        }

        logger.info(classMap.size() + " class(es) were mapped!");
        return classMap;
    }

    private MyAbstractClass makeInstance(Class<? extends MyAbstractClass> abstractClass) throws NoSuchMethodException,
            InstantiationException, InvocationTargetException, IllegalAccessException {
        Constructor<?> classConstructor = abstractClass.getConstructor();
        return (MyAbstractClass) classConstructor.newInstance();
    }
}