【发布时间】：2018-01-08 15:58:35
【问题描述】：
我是编程新手，我有一个小问题，我正在尝试制作一个使用 json 来读取 flickr api 的应用程序，但我在环顾四周的描述中收到错误提及，但没有一个解决方案有效，所以我过来问
public class JSONPareser {
final String TAG = "JSONParser";
public String makeServiceCall(String reqUrl) {
String response = null;
try {
URL url = new URL(reqUrl);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
// read the response
InputStream in = new BufferedInputStream(conn.getInputStream());
response = convertStreamToString(in);
} catch (MalformedURLException e) {
Log.e(TAG, "MalformedURLException: " + e.getMessage());
} catch (ProtocolException e) {
Log.e(TAG, "ProtocolException: " + e.getMessage());
} catch (IOException e) {
Log.e(TAG, "IOException: " + e.getMessage());
} catch (Exception e) {
Log.e(TAG, "Exception: " + e.getMessage());
}
return response;
}
private String convertStreamToString(InputStream is) throws UnsupportedEncodingException {
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"UTF-8"),8);
StringBuilder sb = new StringBuilder();
String line;
try {
while ((line = reader.readLine()) != null) {
sb.append(line).append('\n');
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
}
这是我的解析器类，这是我调用 json 对象的时候
public class getData extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
dialog = new ProgressDialog(MainActivity.this);
dialog.setMessage("Please wait");
dialog.setCancelable(false);
dialog.show();
}
@Override
protected Void doInBackground(Void... params) {
String url = "https://api.flickr.com/services/feeds/photos_public.gne";
JSONPareser pareser = new JSONPareser();
String jsonStr = pareser.makeServiceCall(url);
if (jsonStr != null) {
try {
JSONArray jsonArray = new JSONArray(jsonStr);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject obj = jsonArray.getJSONObject(i);
FlickrModel model = new FlickrModel();
model.setLink(obj.getString("link"));
model.setDescription(obj.getString("description"));
model.setTitle(obj.getString("title"));
model.setAuthor(obj.getString("author"));
model.setTags(obj.getString("tags"));
flickrList.add(model);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG)
.show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG)
.show();
}
});
}
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (dialog.isShowing()) {
dialog.dismiss();
}
非常感谢你
【问题讨论】：
-
给你一个提示，你不需要来自 onPostExecute 方法的 runOnUiThread；
-
您能否粘贴响应，因为它显示 xml 响应即将到来。我认为 url 架构不正确或服务器未启动，因此发送 xml 而不是 json 作为响应... JsonParser 的最低要求要解析的是响应字符串必须是 json 格式。