ReflectionUtils.java

package fr.openwide.core.spring.util;

import java.lang.annotation.Annotation;
import java.util.LinkedHashSet;
import java.util.Set;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.context.annotation.ClassPathScanningCandidateComponentProvider;
import org.springframework.core.type.filter.AnnotationTypeFilter;
import org.springframework.core.type.filter.AssignableTypeFilter;
import org.springframework.core.type.filter.TypeFilter;

public final class ReflectionUtils {
	
	private static final Logger LOGGER = LoggerFactory.getLogger(ReflectionUtils.class);

	public static <T> Set<Class<? extends T>> findAssignableClasses(String rootPackage, Class<T> clazz) {
		return findClasses(rootPackage, clazz, new AssignableTypeFilter(clazz));
	}
	
	public static Set<Class<? extends Object>> findAnnotatedClasses(String rootPackage, Class<? extends Annotation> annotationType) {
		return findClasses(rootPackage, Object.class, new AnnotationTypeFilter(annotationType));
	}
	
	@SuppressWarnings("unchecked")
	private static <T> Set<Class<? extends T>> findClasses(String rootPackage, Class<T> clazz, TypeFilter filter) {
		ClassPathScanningCandidateComponentProvider scanner = new ClassPathScanningCandidateComponentProvider(false);
		scanner.addIncludeFilter(filter);
		
		Set<BeanDefinition> beanDefinitions = scanner.findCandidateComponents(rootPackage);
		Set<Class<? extends T>> classes = new LinkedHashSet<Class<? extends T>>();
		
		for (BeanDefinition beanDefinition : beanDefinitions) {
			try {
				classes.add((Class<? extends T>) Class.forName(beanDefinition.getBeanClassName()));
			} catch (ClassNotFoundException e) {
				LOGGER.warn("Class not found: " + beanDefinition.getBeanClassName());
			}
		}
		
		return classes;
	}
	
	private ReflectionUtils() {
	}

}