@SuppressWarnings("rawtypes")
	private Class isValidField(Class entityClass) {
		String fieldName = null;
		Class fieldType = null;
		boolean isValidFieldName = false;
		for (Field field : entityClass.getDeclaredFields()) {
			fieldName = field.getName();
			/*Annotation[] annotations = field.getDeclaredAnnotations();*/

			if (fieldName.equals(this.field)) {
				isValidFieldName = true;
				fieldType = field.getType();
				break;
			}
		}
		if (!isValidFieldName) {
			throw new IllegalArgumentException(
					"The field specified doesn't exist.");
		}
		return fieldType;
	}