使用GSON获取JSON密钥名称

问题描述

  {
bjones：{
fname：Betty，
lname：Jones，
密码：ababab，
等级：经理
 } 
} 
  

我的User类有一个用户名，它需要JSON对象的键用过的。我怎么会得到我的JSON对象的关键？

现在我得到的都是创建一个新的用户对象，但留下用户名为空。这是可以理解的，因为我的JSON对象不包含username的键/值对：value。

  Gson gson = new Gson（）; 
 JsonParser p = new JsonParser（）; 
 JsonReader file = new JsonReader（new FileReader（this.filename））; 
 JsonObject result = p.parse（file）.getAsJsonObject（）。getAsJsonObject（bjones）; 
 User newUser = gson.fromJson（result，User.class）; 
 
 // newUser.username = null 
 // newUser.fname =Betty
 // newUser.lname =Jones
 // newUser.password =ababab
 // newUser.level =manager
  

编辑：
我试图用Gson在newUser.username中插入bjones，对于没有澄清的问题抱歉

获得钥匙。循环访问条目并为每个键创建一个用户。

  JsonObject result = p.parse（file）.getAsJsonObject（）; 
 Set< Map.Entry< String，JsonElement>> entrySet = result.entrySet（）; （Map.Entry< String，JsonElement> entry：entrySet）{
 User newUser = gson.fromJson（p.getAsJsonObject（entry.getKey（）），User.class）; 
 newUser.username = entry.getKey（）; 
 //代码... 
} 
  

I have a JSON array which contains objects such as this:

{
    "bjones": {
        "fname": "Betty",
        "lname": "Jones",
        "password": "ababab",
        "level": "manager"
    }
}

my User class has a username which would require the JSON object's key to be used. How would I get the key of my JSON object?

What I have now is getting everything and creating a new User object, but leaving the username null. Which is understandable because my JSON object does not contain a key/value pair for "username":"value".

Gson gson = new Gson();
JsonParser p = new JsonParser();
JsonReader file = new JsonReader(new FileReader(this.filename));
JsonObject result = p.parse(file).getAsJsonObject().getAsJsonObject("bjones");
User newUser = gson.fromJson(result, User.class);

// newUser.username = null
// newUser.fname = "Betty"
// newUser.lname = "Jones"
// newUser.password = "ababab"
// newUser.level = "manager"

edit:I'm trying to insert "bjones" into newUser.username with Gson, sorry for the lack of clarification

解决方案

Use entrySet to get the keys. Loop through the entries and create a User for every key.

JsonObject result = p.parse(file).getAsJsonObject();
Set<Map.Entry<String, JsonElement>> entrySet = result.entrySet();
for(Map.Entry<String, JsonElement> entry : entrySet) {
    User newUser = gson.fromJson(p.getAsJsonObject(entry.getKey()), User.class);
    newUser.username = entry.getKey();
    //code...
}

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