java - 如何在android中通过for循环创建JSON对象并放入JSON数组？

Question

我有一个 JSON 对象而不是一个 JSON 数组，我想获取该值并创建新的 JSON 对象并再次放入 JSON 数组中。

这里我的 JSONObject 称为响应

{"data":
 [{
    "level":"lv1",
    "name_indo":"Telinga",
    "name_eng":"Ear",
    "detail_indo":"Telinga adalah alat indra yang memiliki fungsi untuk mendengar suara yang ada di sekitar kita.\r\n",
    "detail_eng":"The ear is the sensory apparatus that has a function to hear the sounds that are around us .\r\n",
    "image_url":"\/append_img\/telinga.png”},
{
    “level":"lv1",
    "name_indo":"Gigi",
    "name_eng":"Tooth",
    "detail_indo":"Gigi adalah alat yang digunakan untuk mengolah makanan saat kita makan.\r\n",
    "detail_eng":"Gigi is a tool used to process food when we eat.\r\n",
    "image_url":"\/append_img\/gigi.png"}]
}

这里是我的代码，用于创建一个仅包含 name_eng 值和 image_url 值的新 JSON 数组:

                    try {
                    JSONArray resultArr = response.getJSONArray("data");

                    JSONObject filterJson = null;
                    JSONArray filterArr = null;
                    for (int i = 0; i < resultArr.length(); i++) {
                        Log.v(TAG, "run for");
                        JSONObject finalObj = (JSONObject) resultArr.get(i);
                        String name_eng = finalObj.getString("name-eng");
                        filterJson = new JSONObject();
                        filterJson.put("name_eng", name_eng);

                        filterArr = new JSONArray();
                        filterArr.put(filterJson);
                    }
                    JSONObject fixedJSON = new JSONObject();
                    assert filterArr != null;
                    fixedJSON.put("data", filterArr.toString());
                    Log.v(TAG, "filterarray : "+fixedJSON);
                    } catch (JSONException e) {
                     e.printStackTrace();
                    }

这是我的 LogCat 错误:

03-22 23:50:42.864 10867-10867/tk.partofbodyapp.partofbodyapp E/AndroidRuntime: FATAL EXCEPTION: main
                                                                            Process: tk.partofbodyapp.partofbodyapp, PID: 10867
                                                                            java.lang.NullPointerException: Attempt to invoke virtual method 'org.json.JSONArray org.json.JSONArray.put(java.lang.Object)' on a null object reference
                                                                                at tk.partofbodyapp.partofbodyapp.startgameActivity$startJson.onPostExecute(startgameActivity.java:191)
                                                                                at tk.partofbodyapp.partofbodyapp.startgameActivity$startJson.onPostExecute(startgameActivity.java:88)
                                                                                at android.os.AsyncTask.finish(AsyncTask.java:636)
                                                                                at android.os.AsyncTask.access$500(AsyncTask.java:177)
                                                                                at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653)
                                                                                at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                                at android.os.Looper.loop(Looper.java:135)
                                                                                at android.app.ActivityThread.main(ActivityThread.java:5254)
                                                                                at java.lang.reflect.Method.invoke(Native Method)
                                                                                at java.lang.reflect.Method.invoke(Method.java:372)
                                                                                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

错误startgameActivity.java:191是 filterArr.put(filterJson);

我想再次制作一个 JSON:

{"data":
 [{
    "name_eng":"Ear",
    "image_url":"\/append_img\/telinga.png”},
{
    "name_eng":"Tooth",
    "image_url":"\/append_img\/gigi.png"}]
}

有什么想法吗？

Answer 1

试试这个

try {
    JSONArray resultArr = response.getJSONArray("data");
    JSONArray filterArr = new JSONArray();
    for (int i = 0; i < resultArr.length(); i++) {
        Log.v(TAG, "run for");
        JSONObject filterJson = new JSONObject();
        JSONObject finalObj = (JSONObject) resultArr.get(i);
        String name_eng = finalObj.getString("name-eng");
        String image_url = finalObj.getString("image_url");
        filterJson.put("name_eng", name_eng);
        filterJson.put("image_url", image_url);
        filterArr.put(filterJson);
    }
    JSONObject fixedJSON = new JSONObject();
    assert filterArr != null;
    fixedJSON.put("data", filterArr);
    Log.v(TAG, "filterarray : "+fixedJSON);
} catch (JSONException e) {
    e.printStackTrace();
}