JSON Tutorial

Case - Lock / Unlock Settings Item

Git Log Tag: [ GSON Tutorial ] - [ Change Settings Access ]

Solution & codes

  • Default: Use JSON as default configuration file, because it is easier to save all settings item with full tree structure. Save the json file in res/raw/.
  • View: Use Fragment & RecyclerView to implement UI part.
  • Model: Create data model according to item tree structure: title, locked, pref-key , parent-item, sub-items. The parent-item & sub-items are important to enter sub-level and back to high-level, and also important to update parent & sub checked status when one item is changed.
  • Model Update: The best & easier way is to use Preferences to save and get the item locked status. It's hard to update Json file (find the JsonObject in the tree, then modify it, then convert JsonObject to String, then write string to file).

Utilities

JSON Formatter Online 一个在线的 Json 格式化网站。只需要粘贴 Json 字串或者上传 Json 文件，选择缩进等级，然后格式化。

JSON Editor Online 一个在线的 Json 编辑网站。Json String 和 Json Object 可以互相生成。右侧的 Json Object 编辑器可以很方便地修改类型、插入、删除、复制，在线保存（会自动生成一个链接）或者保存到本地。

Mapping of Nested Objects

You'll need to go from top-level to the deepest level until your nested JSON only has regular types left. 如果只取 Json 文件的一部分转换，会导致 java object 成员为 null。

Custom Deserialization Basics

If your server sends you data in a format, which doesn't match your client's application data model, The better way is to customize the deserialization and combine them to a date object right away. Within your application you'll never know that the server send it in that format and you can abstract differences between server and client away. 但是自定义后，所有的 json 字段都需要处理了，为什么不能只处理部分字段呢？TODO

{
    "year": 116,
    "month": 5,
    "day": 21,
    "age": 26,
    "email": "[email protected]",
    "isDeveloper": true,
    "name": "Norman"
}