So first you create an empty map using the [:] notation.
所以首先要使用[：]符号创建一个空映射。
If you leave a String field blank in an HTML form, it comes back to the controller in the params Map as an empty String (that is, ) instead of null.
如果在HTML表单中将String字段保留为空，paramsmap中的控制器会将其看作空string(也就是“ ”)，而不是null。
But it's not completely empty, as a new map of the interstellar space in the 1, 000 light-years around the sun shows.
但它又不是完全的空无一物，正如这张最新的太阳周边1000光年范围内星际空间地图所示。
In the example here, you don't need a response, so an empty Hash map is used.
在本例中，您不需要响应，因此使用了空的Hashmap。
Eleventh strokes, do not send an empty package, write the EMS number on the ok, the path map and Taobao networking, Taobao is not a good search.
第十一招，别发空包裹，写ems号码就ok，路径图没有和淘宝联网，淘宝不好查。
Eleventh strokes, do not send an empty package, write the EMS number on the ok, the path map and Taobao networking, Taobao is not a good search.
第十一招，别发空包裹，写ems号码就ok，路径图没有和淘宝联网，淘宝不好查。
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