我试图使用AsyncTask它在设备有互联网连接的情况下工作，但是当我打开没有互联网的情况时出现此消息＆＃34;不幸的是，已停止＆＃34;，按照代码，我是什么做错了？有人可以解释一下吗？
PS：我有一个Activity，我在Fragment中使用AsyncTask。
使用AsyncTask的片段。
public class MasonFragment extends Fragment {
private ListView lstMason;
private ProgressDialog dialog;
//private Fragment fragmentMain = new MainFragment();
public MasonFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_mason, container, false);
lstMason = (ListView)view.findViewById(R.id.lstMason);
// Create default options which will be used for every
// displayImage(...) call if no options will be passed to this method
DisplayImageOptions defaultOptions = new DisplayImageOptions.Builder().cacheInMemory(true).cacheOnDisk(true).build();
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getActivity())
.defaultDisplayImageOptions(defaultOptions).build();
ImageLoader.getInstance().init(config); // Do it on Application start
//To that class work need this: compile 'com.nostra13.universalimageloader:universal-image-loader:1.9.5' in gradle module
new JSONTask().execute("https://deliveryteste.000webhostapp.com/production_version_1/json_services_v1.txt");
return view;
}
/*private View.OnClickListener requestJSON = new View.OnClickListener() {
@Override
public void onClick(View v) {
new JSONTask().execute("My_URL");
}
};*/
public class JSONTask extends AsyncTask<String, String, List<Services>> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected List<Services> doInBackground(String... params) {
if(new CheckNetwork(getActivity()).isNetworkAvailable()) {
HttpURLConnection connection = null;
BufferedReader reader = null;
try {
URL url = new URL(params[0]);
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String finalJson = buffer.toString();
JSONObject jsonObject = new JSONObject(finalJson);
JSONArray jsonArray = jsonObject.getJSONArray("mason");
List<Services> servicesList = new ArrayList<>();
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject finalObject = jsonArray.getJSONObject(i);
Services services = new Services();
services.setName(finalObject.getString("name"));
services.setTelephone(finalObject.getString("telephone"));
services.setCity(finalObject.getString("city"));
services.setDescription(finalObject.getString("description"));
services.setRating((float) finalObject.getDouble("rate"));
services.setImage(finalObject.getString("image"));
services.setFacebook(finalObject.getString("facebook"));
servicesList.add(services);
}
return servicesList;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
//backToMain();
} finally {
if (connection != null) {
connection.disconnect();
}
try {
if (reader != null) {
reader.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
} else {
Toast.makeText(getActivity(), "Por favor esteja conectado com a rede!", Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(List<Services> result) {
super.onPostExecute(result);
ServicesAdapter servicesAdapter = new ServicesAdapter(getActivity(), R.layout.custom_listview, result);
lstMason.setAdapter(servicesAdapter);
}
}
//Class to CustomArrayAdapter
public class ServicesAdapter extends ArrayAdapter {
private List<Services> servicesList;
private int resource;
private LayoutInflater inflater;
public ServicesAdapter(Context context, int resource, List<Services> objects) {
super(context, resource, objects);
servicesList = objects;
this.resource = resource;
inflater = (LayoutInflater) getActivity().getSystemService(LAYOUT_INFLATER_SERVICE);
}
@NonNull
@Override
public View getView(int position, View convertView, ViewGroup parent) {
if(convertView == null){
convertView = inflater.inflate(resource, null);
}
ImageView imgPerson;
TextView lblName;
TextView lblTelephone;
TextView lblDescription;
TextView lblFacebookResult;
TextView lblCity;
RatingBar rtgServiceRating;
imgPerson = (ImageView)convertView.findViewById(R.id.imgPerson);
lblName = (TextView)convertView.findViewById(R.id.lblName);
lblTelephone = (TextView)convertView.findViewById(R.id.lblTelephone);
lblCity = (TextView)convertView.findViewById(R.id.lblCity);
lblDescription = (TextView)convertView.findViewById(R.id.lblDescription);
lblFacebookResult = (TextView)convertView.findViewById(R.id.lblFacebookResult);
rtgServiceRating = (RatingBar)convertView.findViewById(R.id.rtgSerciveRating);
// Then later, when you want to display image
ImageLoader.getInstance().displayImage(servicesList.get(position).getImage(), imgPerson); // Default options will be used
lblName.setText(servicesList.get(position).getName());
lblTelephone.setText(String.valueOf(servicesList.get(position).getTelephone()));
lblDescription.setText(servicesList.get(position).getDescription());
lblFacebookResult.setText(servicesList.get(position).getFacebook());
lblCity.setText(servicesList.get(position).getCity());
//Rating Bar
rtgServiceRating.setRating(servicesList.get(position).getRating());
StringBuffer stringBuffer = new StringBuffer();
return convertView;
}
}
/*private void backToMain(){
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.lnlContentMain, fragmentMain).commit();
}*/
检查网络连接的类：
public class CheckNetwork {
private Context context;
public CheckNetwork(Context context) {
this.context = context;
}
public boolean isNetworkAvailable() {
ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}
错误日志：
01-30 17:30:13.886 6868-7284/com.archtech.gabrielgomes.hirehere E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.archtech.gabrielgomes.hirehere, PID: 6868
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.SecurityException: ConnectivityService: Neither user 10204 nor current process has android.permission.ACCESS_NETWORK_STATE.
at android.os.Parcel.readException(Parcel.java:1472)
at android.os.Parcel.readException(Parcel.java:1426)
at android.net.IConnectivityManager$Stub$Proxy.getActiveNetworkInfo(IConnectivityManager.java:1139)
at android.net.ConnectivityManager.getActiveNetworkInfo(ConnectivityManager.java:690)
at com.archtech.gabrielgomes.hirehere.CheckNetwork.isNetworkAvailable(CheckNetwork.java:21)
at com.archtech.gabrielgomes.hirehere.fragments.MasonFragment$JSONTask.doInBackground(MasonFragment.java:100)
at com.archtech.gabrielgomes.hirehere.fragments.MasonFragment$JSONTask.doInBackground(MasonFragment.java:90)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
谢谢你们。
答案 0 :(得分：1)
如错误所述，public class Program {
public static void checkIfEqualOption1(int[] arr){
int sumRight = 0;
int sumLeft=0;
int arrayLength=arr.length;
for (int posFromLeft=0; posFromLeft < arrayLength; posFromLeft++){
int posFromRight=arrayLength-posFromLeft-1;
if (posFromRight > posFromLeft){
sumRight+=arr[posFromRight];
sumLeft+=arr[posFromLeft];
}
}
System.out.println("right sum: "+sumRight);
System.out.println("left sum: "+sumLeft);
}
public static void main(String[] args) {
int[] numbers = {1,2,2,9,3};
System.out.println("Array numbers:");
for (int i=0; i < numbers.length; i++){
System.out.print(numbers[i] + " ");
}
checkIfEqualOption1(numbers);
}
}
要解决此问题，只需将java.lang.SecurityException: ConnectivityService: Neither user 10204 nor current process has android.permission.ACCESS_NETWORK_STATE添加到<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />文件