有没有一种方法可以将Key存储在Firebase对象所投的类中？ [英] Is there a way to store Key in class which I cast from Firebase object?

问题描述

  [x] database 
  - > [+]学生
 -----> [+] -KuGacomJymBwkcc7zlU（pushKey）
 ----------->名称 -  Jon 
 ----------->年龄 -  21 
  

我有Student.class：

 字符串名称; 
字符串年龄; 
 
 public Student（String Name，String Age）{
 this.name = Name; 
 this.age =年龄; 
 
 $ / code> 

我从firebase datasnapshot读取这些信息：



 学生newStudent = DataSnapshot.getValue（Student.class）; 
  

当我这样做的时候，我得到了名字和年龄，但是我的问题是否有办法将ID（pushKey）存储在Student类中，而不需要添加一个字符串来保存它，并在Firebase数据库中取另一个字段。



谢谢大家。

解决方案

我更喜欢保持键和值分开，否则传递 DataSnapshot 周围。但是，如果你愿意，你也可以提取键（ DataSnapshot.getKey（）），并将其设置在Java类中的一个属性排除：

  public class Student {
 @Exclude 
 public String key ; 
公共字符串名称; 
 public String age; 
 
 $ / code> 

然后：



  Student newStudent = snapshot.getValue（Student.class）; 
 newStudent.key = snapshot.getKey（）; 
  

相关：



• 如何管理Firebase数据库密钥？
• 
  
• 获取参考并输入自定义对象Firebase Android

This is my database :

[x] database
-- > [+] students
-----> [+] -KuGacomJymBwkcc7zlU (pushKey)
-----------> Name - Jon
-----------> Age - 21

I have Student.class :

String name;
String age;

public Student(String Name, String Age) {
this.name=Name;
this.age=Age;
}

I read the information from firebase datasnapshot like this:

Student newStudent = DataSnapshot.getValue(Student.class);

When I do this I get the name and the age, but my question if there is a way to store the ID (pushKey) on the Student class without adding a String that will hold it and take another field on the firebase database.

Thank you all.

解决方案

I prefer keeping the keys and the values separate, or otherwise passing the DataSnapshots around. But if you want, you can also extract the key (DataSnapshot.getKey()) and set it on a property in your Java class that you @Exclude:

public class Student {
  @Exclude
  public String key;
  public String name;
  public String age;
}

And then:

Student newStudent = snapshot.getValue(Student.class);
newStudent.key = snapshot.getKey();

Related:

• How to manage firebase database keys?
• Obtaining the reference and key in Custom Object Firebase Android

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