Question

我有一个由JSONArray组成的JSON。如何从JSONArrays中获取关键字符串列表？

例如：

{
  "mainKey": [
    {
      "keyValue1": [
        {
          "id": 9000, 
          "name": "John Doe"
        }
      ]
    }, 
    {
      "keyValue2": []
    }, 
    {
      "keyValue3": []
    }, 
    {
      "keyValue4": []
    }
  ]
}

我想获得一个带有keyValue1，keyValue2等的ArrayList。我应该如何用Java做到这一点？

Answer 1

试试这个：

JSONObject obj = new JSONObject(yourJsonString);
JSONArray array = obj.getJSONArray("mainKey");
for(int n = 0; n < array.length(); n++)
{
    JSONObject keyObject = array.getJSONObject(n);
    Iterator<?> keys = keyObject.keys();
    while( keys.hasNext() ) {
        String key = (String)keys.next();
        if ( obj.get(key) instanceof JSONArray ) {
            System.out.println(key);
        }
    }
}

Answer 2

我在Android AsyncTask中执行此操作：

ArrayList<String> arrayList = new ArrayList<String>();
Spinner spinner;

...

       @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_fragment_class, container, false);

spinner = (Spinner) rootView.findViewByID(R.id.spinner);

LoadFromAPI task = new LoadFromAPI();
task.execute(url);   // a valid url in a localhost


        ArrayAdapter<String> adapter = new ArrayAdapter<String>(rootView.getContext(),
                android.R.layout.simple_spinner_item, arrayList);
return rootView;
}
    private class LoadFromAPI extends AsyncTask<String, Void, Void> {

    protected void doInBackground (String... url) {
        JSONObject obj = new JSONObject(yourJsonString);
        JSONArray array = obj.getJSONArray("mainKey");
        for(int n = 0; n < array.length(); n++)
        {
            JSONObject keyObject = array.getJSONObject(n);
            Iterator<?> keys = keyObject.keys();
            while( keys.hasNext() ) {
                String key = (String)keys.next();
                if ( obj.get(key) instanceof JSONArray ) {
                    arrayList.add(key);
                }
            }
        }
    }

Answer 3

在Java 8中：

alert(colorsObj.color1[i]);

来自JSONArray的关键值列表（java / android）

3 个答案: