GenericEntityUtils.java

package fr.openwide.core.jpa.business.generic.util;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import fr.openwide.core.jpa.business.generic.model.GenericEntity;

public final class GenericEntityUtils {

	public static Class<?> getGenericEntityClassFromComponentDefinition(Class<?> clazz) {
		int retriesCount = 0;
		
		while(true) {
			if (clazz.getGenericSuperclass() instanceof ParameterizedType) {
				Type[] argumentTypes = ((ParameterizedType) clazz.getGenericSuperclass()).getActualTypeArguments();
				
				for (Type argumentType : argumentTypes) {
					Class<?> argumentClass;
					
					if (argumentType instanceof ParameterizedType) {
						argumentClass = (Class<?>) ((ParameterizedType) argumentType).getRawType();
					} else {
						argumentClass = (Class<?>) argumentType;
					}
					
					if (GenericEntity.class.isAssignableFrom(argumentClass)) {
						return argumentClass;
					}
				}
			}
			
			clazz = clazz.getSuperclass();
			retriesCount ++;
			
			if (retriesCount > 5) {
				throw new IllegalArgumentException("Unable to find a generic type extending GenericEntity.");
			}
		}
	}
	
	private GenericEntityUtils() {
	}
	
}