Using GSON to parse a JSON array

I have a JSON file like this:

[
{
"number": "3",
"title": "hello_world",
}, {
"number": "2",
"title": "hello_world",
}
]

Before when files had a root element I would use:

Wrapper w = gson.fromJson(JSONSTRING, Wrapper.class);

code but I can't think how to code the Wrapper class as the root element is an array.

I have tried using:

Wrapper[] wrapper = gson.fromJson(jsonLine, Wrapper[].class);

with:

public class Wrapper{


String number;
String title;


}

But haven't had any luck. How else can I read this using this method?

P.S I have got this to work using:

JsonArray entries = (JsonArray) new JsonParser().parse(jsonLine);
String title = ((JsonObject)entries.get(0)).get("title");

But I would prefer to know how to do it (if possible) with both methods.

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最佳答案

Problem is caused by comma at the end of (in your case each) JSON object placed in the array:

{
"number": "...",
"title": ".." ,  //<- see that comma?
}

如果你删除它们，你的数据将成为

[
{
"number": "3",
"title": "hello_world"
}, {
"number": "2",
"title": "hello_world"
}
]

还有

Wrapper[] data = gson.fromJson(jElement, Wrapper[].class);

应该没问题。

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Gson gson = new Gson();
Wrapper[] arr = gson.fromJson(str, Wrapper[].class);


class Wrapper{
int number;
String title;
}

似乎工作正常。但有一个额外的 ,逗号在您的字符串。

[
{
"number" : "3",
"title" : "hello_world"
},
{
"number" : "2",
"title" : "hello_world"
}
]

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public static <T> List<T> toList(String json, Class<T> clazz) {
if (null == json) {
return null;
}
Gson gson = new Gson();
return gson.fromJson(json, new TypeToken<T>(){}.getType());
}

样品电话:

List<Specifications> objects = GsonUtils.toList(products, Specifications.class);

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Wrapper[] data = gson.fromJson(jElement, Wrapper[].class);