如何使用 Gson 库反序列化 JSON 对象数组？

Question

I am facing an issue while I am trying to deserialize a JSON array of objects using the Gson library.

An example of the JSON array:

[
    {"ID":1,"Title":"Lion","Description":"bla bla","ImageURL":"http:\/\/localhost\/lion.jpg"},
    {"ID":1,"Title":"Tiger","Description":"bla bla","ImageURL":"http:\/\/localhost\/tiger.jpg"}
]

What do you think? What is the proper Java code to deserialize such a JSON response?

Answer 1

To deserialize a JSONArray you need to use TypeToken. You can read more about it from GSON user guide . Example code:

@Test
public void JSON() {
    Gson gson = new Gson();
    Type listType = new TypeToken<List<MyObject>>(){}.getType();
    // In this test code i just shove the JSON here as string.
    List<Asd> asd = gson.fromJson("[{'name':\"test1\"}, {'name':\"test2\"}]", listType);
}

If you have a JSONArray then you can use

...
JSONArray jsonArray = ...
gson.fromJson(jsonArray.toString(), listType);
...

Answer 2

For example your service has such response

[ new SomeObject(), new SomeObject(), new SomeObject() ] - this is jsonArray

SomeObject - is a class instance of that your array is contains.

You should use special class TypeToken (docs here https://sites.google.com/site/gson/gson-user-guide )

Type type = new TypeToken<List<SomeObject>>(){}.getType();



String jsonArray = restResponse.getPayload(); - you get response as String
List<SomeObject > list = new Gson().fromJson(jsonArray, type);

Done!