使用谷歌gson的json对象序列化/反序列化 [英] json object serialization/deserialization using google gson

问题描述

我想序列化/反序列化Java对象到/从json。谷歌GSON是可取的。
让我有A类：

I want to serialize/deserialize java objects to/from json. the google gson is preferable. Let I have class A:

class A {
  int x = 1;
  int y = 2; 
}

然后，如果我调用新的Gson（）。toJson（new A（）），我会得到以下结果：

Then, if I call new Gson().toJson(new A()) I will get the following:

{ x: 1, y : 2}. 

然而，我想要有

However I want to have

{class : "A", x:1, y:2}

所以我可以在不知道类名的情况下使用反射进行反序列化时间。我该怎么做？
谢谢。

So I can deserialize it using reflection without knowing the class name at compile time. How may I do it? Thank you.

推荐答案

如果使用Gson或更好，那么具体到如何生成JSON结构类的结构 {class：A，x：1，y：2} class A {int x = 1; int y = 2;} ，目前需要实现自定义序列化。同样，要从此JSON反序列化为此Java结构，则必须实现自定义反序列化。

If Gson use is preferable or required, then specific to the question of how to generate JSON of the structure {class:"A", x:1, y:2} from a Java instance of the structure class A {int x = 1; int y = 2;}, it's currently necessary to implement custom serialization. Similarly, to deserialize from this JSON to this Java structure, then it's necessary to implement custom deserialization.

与此类手动处理不同，请注意，Gson很快将拥有 RuntimeTypeAdapter 可用于更简单的多态反序列化。请参阅 http://code.google.com/p/google- gson / issues / detail？id = 231 了解更多信息。即使您不能使用 RuntimeTypeAdapter ，它至少提供了一个创建可配置的自定义反序列化器的示例。

Instead of such "manual" processing, note that Gson will soon have the RuntimeTypeAdapter available for simpler polymorphic deserialization. See http://code.google.com/p/google-gson/issues/detail?id=231 for more info. Even if you cannot use the RuntimeTypeAdapter, it at least provides an example for creating a configurable custom deserializer.

如果您可以切换JSON映射API，然后我建议考虑 Jackson ，因为它具有可用的相对简单的多态解串器机制。我在 http：//programmerbruce.blogspot上发布了一些简单的示例.com / 2011/05 / deserialize-json-with-jackson-into.html 。

If you can switch JSON mapping APIs, then I recommend considering Jackson, as it has a working and relatively simple polymorphic deserializer mechanism available. I posted some simple examples at http://programmerbruce.blogspot.com/2011/05/deserialize-json-with-jackson-into.html.

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