code: public static Type getType(Field field) {
  		if (null == field) {
  			return null;
  		}
  		Type type = field.getGenericType();
  		if (null == type) {
  			type = field.getType();
  		}
  		return type;
  	}
docs: 获取字段对应的Type类型<br>
  方法优先获取GenericType，获取不到则获取Type
  
  @param field 字段
  @return {@link Type}，可能为{@code null}