如何在Firebase类中表示嵌套数据 [英] How to represent nested data in Firebase class

问题描述

从Firebase的例子来看，如果我有这样一个恐龙事实数据结构：

$ p $ {
lambeosaurus：{
name：lamby，
work：eat，
dimensions：{
height：2.1，
长度：12.5，
重量：5000
}
}，
剑龙：{
name：stego，
work：play，
dimensions：{
height：4，
length：9，
weight：2500







$用于Firebase的Android类从 DataSnapshot.getValue（DinosaurFacts.class）投射？

名称和工作作为字符串，但如何表示类中的维度集合？

另外我怎样才能从 DataSnapshot 关于身高&重量？

编辑
我可以通过快照获取单个元素循环，但是试图找到如何表示数据（DataSnapshot child：dataSnapshot.getChildren（））{

Log（）;

  .d（hz-key：，child.getKey（）。toString（））; 
 Log.d（hz-val：，child.getValue（）。toString（））; 
 
 $ / code $ / pre 
 
解决方案
 
结构是： 
 
 
  public static class DinosaurFacts {
 String name; 
字符串工作; 
尺寸尺寸; 
 
 public String getName（）{
 return name; 
} 
 
 public String getWork（）{
 return work; 
} 
 
公共维度getDimensions（）{
 return dimensions; 
} 
 
 public class Dimensions {
 double height; 
长的重量; 
双倍长度; 
 
 public double getHeight（）{
 return height; 
} 
 
 public long getWeight（）{
 return weight; 
} 
 
 public double getLength（）{
 return length; 
 
 
 
 
 
然后你可以读一个恐龙与： 
 
 
  DinosaurFacts dino = dinoSnapshot.getValue（DinosaurFacts.class）; 
  
访问维度，例如：
 
 
  dino.getDimensions（）getWeight（）; 
  
 
Taken from the Firebase example, if I have a Dinosaurs facts data structure like this:
{
  "lambeosaurus": {
    "name": "lamby",
    "work": "eat",
    "dimensions": {
      "height" : 2.1,
      "length" : 12.5,
      "weight": 5000
    }
  },
  "stegosaurus": {
    "name": "stego",
    "work": "play",
    "dimensions": {
      "height" : 4,
      "length" : 9,
      "weight" : 2500
    }
  }
}
How can I represent this structure in a Android Class for Firebase to cast from DataSnapshot.getValue(DinosaurFacts.class)?

name, and work are represented as Strings, but how to represent "dimensions" collection in the class?

Also how can I access data values from DataSnapshot about height & weight?

EDIT
I can get the individual elements looping through the snapshot, but am trying to find how to represent the data in the class structure.
for(DataSnapshot child : dataSnapshot.getChildren()) {

                Log.d("hz-key:", child.getKey().toString());
                Log.d("hz-val:", child.getValue().toString());
            }

解决方案
The JavaBean class to represent this structure is:
public static class DinosaurFacts {
    String name;
    String work;
    Dimensions dimensions;

    public String getName() {
        return name;
    }

    public String getWork() {
        return work;
    }

    public Dimensions getDimensions() {
        return dimensions;
    }

    public class Dimensions {
        double height;
        long weight;
        double length;

        public double getHeight() {
            return height;
        }

        public long getWeight() {
            return weight;
        }

        public double getLength() {
            return length;
        }
    }
}
Then you can read a dino with:
DinosaurFacts dino = dinoSnapshot.getValue(DinosaurFacts.class);
And access the dimensions with for example:
dino.getDimensions().getWeight();


                        
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