java - 如何将 JSONObject 写入 firebase 数据库节点

Question

我目前正在尝试将应用从 SQLDatabase 迁移到 Firebase。我已经完成了将数据库转换为 JSONObject 的所有工作。有没有办法可以用这个对象填充 firebase 中的用户节点？

我尝试用

编写 JSONObject

database.getReference("/" + user.getUid() + "/").setValue(jsonObject);

这会返回错误

com.google.firebase.database.DatabaseException: No properties to serialize found on class org.json.JSONObject

我试图避免分解对象并单独发布单独的值，因为这可能容易出错，而且我不能冒着因困惑的循环而损坏数据的风险...感谢您的帮助。

Answer 1

您可以使用ObjectMapper将json转换为对象:

ObjectMapper mapper = new ObjectMapper();
User user = mapper.readValue(jsonObject.toString(), User.class);

https://fasterxml.github.io/jackson-databind/javadoc/2.7/com/fasterxml/jackson/databind/ObjectMapper.html

然后您可以在setValue()中使用User类的实例:

database.getReference("/" + user.getUid() + "/").setValue(user);

来自文档:

In addition, you can set instances of your own class into this location, provided they satisfy the following constraints:

The class must have a default constructor that takes no arguments

The class must define public getters for the properties to be assigned. Properties without a public getter will be set to their default value when an instance is deserialized