[英]How to get the values of a key of a json file
private void getWebApiData() {
String WebDataUrl = "myjsonfileurl";
new AsyncHttpTask.execute(WebDataUrl);
}
@SuppressLint("StaticFieldLeak")
public class AsyncHttpTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... urls) {
String result = "";
URL url;
HttpsURLConnection urlConnection = null;
try {
url = new URL(urls[0]);
urlConnection = (HttpsURLConnection) url.openConnection();
if (result != null) {
String response = streamToString(urlConnection.getInputStream());
parseResult(response);
return result;
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String result) {
if (result != null) {
newsAdapter = new NewsAdapter(getActivity(), newsClassList);
listView.setAdapter(newsAdapter);
Toast.makeText(getContext(), "Data Loaded Successfully", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getContext(), "Failed to load data!", Toast.LENGTH_SHORT).show();
}
progressBar.setVisibility(View.GONE);
}
}
private String streamToString(InputStream stream) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(stream));
String line;
String result = "";
while ((line = bufferedReader.readLine()) != null) {
result += line;
}
// Close stream
if (null != stream) {
stream.close();
}
return result;
}
private void parseResult_GetWebData(String result) {
try {
JSONObject jsonObject = new JSONObject(result);
JSONArray jsonArray = jsonObject.getJSONArray("books");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject articleObject = jsonArray.getJSONObject(i);
JSONObject sourceObject = articleObject.getJSONObject("A");
String name = sourceObject.optString("name");
}
} catch (JSONException e) {
e.printStackTrace();
}
}
我的json文件
{
"books": [
{
"A": [
{
"Amazonite": {
"name": "Amazonite",
"image": "www.google.com"
},
"Amethyst": {
"name": "Amethyst",
"image": "www.google.com"
}
}
],
"B": [
{
"Beryl": {
"name": "Beryl",
"image": "www.google.com"
},
"BloodStone": {
"name": "Bloodstone",
"image": "www.google.com"
}
}
]
}
]
}
我想要的是如何獲取 Alphabet A 下的數據值,即 Amazonite 和 Amethyst,以及 Alphabet B 下的數據值,但我可以只給我空文本字段,沒有填充任何數據。 我已嘗試使用此代碼,但值返回“null”
private void parseResult_GetWebData(String result) {
try {
JSONObject jsonObject = new JSONObject(result);
JSONArray jsonArray = jsonObject.getJSONArray("books");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject articleObject = jsonArray.getJSONObject(i);
String name = String.valueOf(articleObject.optJSONObject("A"));
}
} catch (JSONException e) {
e.printStackTrace();
}
}
我不確定你真正想要什么,但如果你只是想在 OP 下回復“Amazonite and Amethyst”,你可以試試這個:
代碼片段
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject articleObject = jsonArray.getJSONObject(i);
JSONArray jsonArrayA = articleObject.getJSONArray("A");
for (int j = 0; j < jsonArrayA.length(); j++) {
JSONObject obj = jsonArrayA.getJSONObject(j);
System.out.println(obj.names());
obj.names().forEach(e -> {
System.out.println(obj.getJSONObject(e.toString()).get("name"));
});
}
}
控制台輸出
[“亞馬遜石”、“紫水晶”]
亞馬遜
紫晶
更新
我不確定您要檢索哪個名稱,因為Amazonite
和Amethyst
在 JSON 數組A
都出現了兩次,因此我提供了兩種顯示它們的方法,如下所示:
List<String> names = new ArrayList<>();
List<String> innerNames = new ArrayList<>();
for (int j = 0; j < jsonArrayA.length(); j++) {
JSONObject obj = jsonArrayA.getJSONObject(j);
JSONArray keys = obj.names();
for (int k = 0; k < keys.length(); k++) {
String name = keys.getString(k);
String innerName = obj.getJSONObject(keys.optString(k)).getString("name");
System.out.printf("name: %s, inner name: %s\n", name, innerName);
names.add(name);
innerNames.add(innerName);
}
}
System.out.println(names.toString());
System.out.println(innerNames.toString());
控制台輸出
名稱:Amazonite,內名:Amazonite
名稱:紫水晶,內名:紫水晶
[亞馬遜石,紫水晶]
[亞馬遜石,紫水晶]
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