更新时间:2023-11-29 09:16:58
JSON对象和数组分别是 JSONObject
和 JSONArray
的实例。除此之外, JSONObject
有一个 get
方法,它会返回一个对象,你可以检查自己的类型不用担心ClassCastExceptions,而且还有。
JSON objects and arrays are instances of JSONObject
and JSONArray
, respectively. Add to that the fact that JSONObject
has a get
method that will return you an object you can check the type of yourself without worrying about ClassCastExceptions, and there ya go.
if (!json.isNull("URL"))
{
// Note, not `getJSONArray` or any of that.
// This will give us whatever's at "URL", regardless of its type.
Object item = json.get("URL");
// `instanceof` tells us whether the object can be cast to a specific type
if (item instanceof JSONArray)
{
// it's an array
JSONArray urlArray = (JSONArray) item;
// do all kinds of JSONArray'ish things with urlArray
}
else
{
// if you know it's either an array or an object, then it's an object
JSONObject urlObject = (JSONObject) item;
// do objecty stuff with urlObject
}
}
else
{
// URL is null/undefined
// oh noes
}