[英]How does Gson.fromJson(String, Class) work?
Consider following sample Json string :考虑以下示例 Json 字符串:
{"Name":"val","FatherName":"val","MotherName":"val"}
I convert the above Json to the following pojo :我将上面的 Json 转换为以下 pojo :
public class Info{
private String name;
private String father;
private String mother;
}
What I am wondering is, when I do the following :我想知道的是,当我执行以下操作时:
Gson.fromJson(jsonLine, Info.class);
How are the keys in json object tracked to the variables in my pojo ? json 对象中的键如何跟踪到我的 pojo 中的变量? How is the value of the key FatherName
stored in father
in Info.class
?如何是关键的价值FatherName
存储在father
的Info.class
?
Gson is using the reflection( https://android.jlelse.eu/reflections-on-reflection-performance-impact-for-a-json-parser-on-android-d36318c0697c ). Gson 正在使用反射( https://android.jlelse.eu/reflections-on-reflection-performance-impact-for-a-json-parser-on-android-d36318c0697c )。 So the example json will not work as expected in your example there are a couple of option to solve this因此示例 json 将无法在您的示例中按预期工作,有几个选项可以解决此问题
Thanks to @Aaron感谢@Aaron
you can also annotated the variables with @SerializedName您还可以使用@SerializedName 注释变量
@SerializedName("father") private string FatherName; @SerializedName("father") 私有字符串FatherName;
In Kotlin, having this class:在 Kotlin 中,有这个类:
import com.google.gson.annotations.SerializedName
data class UsuariosDTO (
@SerializedName("data") var data: List<Usuarios>
)
data class Usuarios(
@SerializedName("uid") var uid: String,
@SerializedName("name") var name: String,
@SerializedName("email") var email: String,
@SerializedName("profile_pic") var profilePic: String,
@SerializedName("post") var post: Post
)
data class Post(
@SerializedName("id") var id: Int,
@SerializedName("date") var date: String,
@SerializedName("pics") var pics: List<String>
)
I'm able to use (where dataObteined is of UsuariosDTO type):我可以使用(其中 dataObteined 是 UsuariosDTO 类型):
val json = gson.toJson(dataObtained)
And later deserialize the json like this:然后像这样反序列化json:
val offUsuariosDTO = gson.fromJson(json, UsuariosDTO::class.java)
After looking everywhere I found out my error was UsuariosDTO.class.到处寻找后,我发现我的错误是 UsuariosDTO.class。 Since Gson is a java library you have to use UsuariosDTO::class.java由于 Gson 是一个 Java 库,因此您必须使用 UsuariosDTO::class.java
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.