使用Java在JSON中的另一个数组中获取数组值

Question

This is my JSON format

{
 "personalData": [
   "firstName": "John",
   "lastName": "Doe",
   "hobby": ["Hiking", "Running", "Swimming"] 
 ]
}

How I can get each element inside "hobby"

This is my existing code that return all item

JSONObject jsonObject = new JSONObject(classJSON.getJSON(getActivity()));
JSONArray jsonArray = jsonObject.getJSONArray("personalData");
JSONObject data = jsonArray.getJSONObject(0);
data.getString("firstName")
// This will return "John"
data.getString("lastName")
// This will return "Doe"
data.getString("hobby")
// This will return ["Hiking", "Running", "Swimming"]
// How I can access each element in "hobby" like how I can get the element in first index.

Answer 1

There's quite a bit wrong with what you currently have.

For instance, your json won't parse because you're defining an array within personalData but you're filling it with key value pairs, which is only allowed within an object.

In reality, your json should look like this:

{
 "personalData": {
   "firstName": "John",
   "lastName": "Doe",
   "hobby": ["Hiking", "Running", "Swimming"] 
 }
}

Given that this is a JSONObject and not a JSONArray, you'll have to replace this:

JSONArray jsonArray = jsonObject.getJSONArray("personalData");
JSONObject data = jsonArray.getJSONObject(0);

With this:

JSONObject data = jsonObject.getJSONObject("personalData");

At which point, you'll be able to extract the hobby array like so:

data.getJSONArray("hobby")

I'm not sure if you've done any testing, but data.getString("hobby") should have thrown a JSONException because it's a JSONArray, not a string.