code: public static Set<Class<?>> scanPackageBySuper(String packageName, final Class<?> superClass) {
  		return scanPackage(packageName, new Filter<Class<?>>() {
  			@Override
  			public boolean accept(Class<?> clazz) {
  				return superClass.isAssignableFrom(clazz) && !superClass.equals(clazz);
  			}
  		});
  	}
docs: 扫描指定包路径下所有指定类或接口的子类或实现类
  
  @param packageName 包路径
  @param superClass 父类或接口
  @return 类集合