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API doesnt work and progressBar keeps spinning

I am a beginner and i am trying to learn how to use APIs on android. I am doing a bitcoin price app to learn APIs. But i have a few problems.I created a progressbar and a price TextView in mainactivity.xml . I set progressbar visible and textview invisible by default.My thought is very simple, i created a new AsyncTask class and after background things are done , i will set the progressbar invisible and the textview visible in the onPostExecute() to show price. But it didn't work. The progressbar keeps spinning, it doesn't show the price i dont understand why it doesn't work.
The API i am using
MainActivity
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
import org.json.JSONObject;
import org.json.JSONTokener;
import java.net.URL;
import java.net.HttpURLConnection;
import java.io.InputStreamReader;
import java.io.BufferedReader;
public class MainActivity extends AppCompatActivity {
public static String line;
public static ProgressBar progressBar;
static String API_URL="https://api.coindesk.com/v1/bpi/currentprice/try.json";
static TextView priceTextView;
static TextView timeTextView;
static int priceInt;
#Override
protected void onCreate( Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
priceTextView=(TextView)findViewById(R.id.priceText);
timeTextView=(TextView)findViewById(R.id.timeText);
progressBar=(ProgressBar)findViewById(R.id.progressBar);
retrievePriceTask retrievePriceTask=new retrievePriceTask();
retrievePriceTask.execute();
}
}
class retrievePriceTask extends AsyncTask <Void,Void,String>{
#Override
protected void onPreExecute() {
MainActivity.progressBar.setVisibility(View.VISIBLE);
MainActivity.priceTextView.setVisibility(View.INVISIBLE);
}
#Override
protected String doInBackground(Void... urls) {
try {
URL url = new URL(MainActivity.API_URL);
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
try {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
StringBuilder stringBuilder = new StringBuilder();
while ((MainActivity.line = bufferedReader.readLine()) != null) {
stringBuilder.append(MainActivity.line).append("\n");
}
bufferedReader.close();
return stringBuilder.toString();
}
finally{
urlConnection.disconnect();
}
}
catch(Exception e) {
Log.e("ERROR", e.getMessage(), e);
return null;
}
}
#Override
protected void onPostExecute(String s) {
MainActivity.priceTextView.setVisibility(View.VISIBLE);
MainActivity.progressBar.setVisibility(View.INVISIBLE);
try{
JSONObject jsonObject=(JSONObject)new JSONTokener(MainActivity.line).nextValue();
MainActivity.priceInt=jsonObject.getJSONObject("bpi").getJSONObject("TRY").getInt("rate");
MainActivity.priceTextView.setText(MainActivity.priceInt);
}
catch (Exception e){
e.printStackTrace();
}
}
}
My Logcat
07-16 10:20:08.884 2269-2269/zaaa.trinki E/AndroidRuntime: FATAL EXCEPTION: main
Process: zaaa.trinki, PID: 2269
java.lang.RuntimeException: Unable to start activity ComponentInfo{zaaa.trinki/zaaa.trinki.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ProgressBar.setVisibility(int)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
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:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ProgressBar.setVisibility(int)' on a null object reference
at zaaa.trinki.retrievePriceTask.onPreExecute(MainActivity.java:94)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
at android.os.AsyncTask.execute(AsyncTask.java:535)
at zaaa.trinki.MainActivity.onCreate(MainActivity.java:55)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
07-16 10:37:42.062 16262-16262/zaaa.trinki E/AndroidRuntime: FATAL EXCEPTION: main
Process: zaaa.trinki, PID: 16262
java.lang.RuntimeException: Unable to start activity ComponentInfo{zaaa.trinki/zaaa.trinki.MainActivity}: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x0
at android.content.res.Resources.getText(Resources.java:274)
at android.support.v7.widget.ResourcesWrapper.getText(ResourcesWrapper.java:52)
at android.widget.TextView.setText(TextView.java:4122)
at zaaa.trinki.MainActivity.onCreate(MainActivity.java:63)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
at android.app.ActivityThread.access$800(ActivityThread.java:144) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:135) 
at android.app.ActivityThread.main(ActivityThread.java:5221) 
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:899) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

Use a ProgressDialog instead of a ProgressBar:
ProgressDialog myProgressDialog = ProgressDialog.show(Context CONTEXT, String TITLE, String MESSAGE, boolean INDETERMINATE, boolean CANCELABLE);
myProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
and in your onPostExecute() just put myProgressDialog.dismiss()

android Unable to start activity ComponentInfo NULL Point Exception

My app work strange on diffrent phones - once everything is fine and other time it crash when i try to make photo and save it in my phone's memory. Photo shows up in folder in memory, but when we should come back to application it is shut down:
06-14 23:58:37.448 12344-12344/com.apps.madzia.photo_application E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.apps.madzia.photo_application, PID: 12344
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.apps.madzia.photo_application/com.apps.madzia.photo_application.activity.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2412)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2470)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4053)
at android.app.ActivityThread.access$1000(ActivityThread.java:174)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5593)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
at android.widget.GridView.setAdapter(GridView.java:187)
at com.apps.madzia.photo_application.fragments.FragmentGallery.onCreateView(FragmentGallery.java:42)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:1786)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1126)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1108)
at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1917)
at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:544)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1177)
at android.app.Activity.performStart(Activity.java:5468)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2385)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2470)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4053)
            at android.app.ActivityThread.access$1000(ActivityThread.java:174)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5593)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
            at dalvik.system.NativeStart.main(Native Method)
The code of my function to make photos:
public void make_photo() {
Calendar c;
c = Calendar.getInstance();
imageName = "fotka_" + c.get(Calendar.YEAR) + "_" + c.get(Calendar.MONTH) + "_" + c.get(Calendar.DAY_OF_MONTH)
+ "_" + c.get(Calendar.HOUR_OF_DAY) + "_" + c.get(Calendar.MINUTE) + "_" + c.get(Calendar.SECOND);
File katalog = new File(IMAGE_FILE_PATH);
File photo = new File(IMAGE_FILE_PATH+imageName + ".jpg");
if( Environment.getExternalStorageState() == Environment.MEDIA_UNKNOWN || Environment.getExternalStorageState() == Environment.MEDIA_REMOVED || Environment.getExternalStorageState() == Environment.MEDIA_UNMOUNTED) {
Log.d("ExternalStorage", "cannot find memory SD card");
File file = new File(getFilesDir(), imageName);
IMAGE_FILE_PATH = file.getParent()+"/";
Log.d("IMAGE_FILE_PATH", IMAGE_FILE_PATH);
}else {
}
Log.d("photo", photo.getPath());
if (!katalog.exists()) {
katalog.mkdirs();
}
try {
// fotka = File.createNewFile(imageName, ".jpg", katalog);
photo.createNewFile();
} catch (IOException e) {
e.printStackTrace();
}
Intent zdjecie = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
zdjecie.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photo));
startActivityForResult(zdjecie, 1);
}

Caused by: java.lang.NullPointerException
at android.widget.ArrayAdapter.getCount(ArrayAdapter.java:330)
at android.widget.GridView.setAdapter(GridView.java:187)
at com.apps.madzia.photo_application.fragments.FragmentGallery.onCreateView(FragmentGallery.java:42)
This means that in your FragmentGallery in onCreateView method on line 42 u are setting null ArrayAdapter

Android MediaRecorder NullPointerException

Im just starting out with Java Development and i am fiddling around with the Android Media recorder. However I am getting a NullPointerException which I click the record button using the following source code:
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
//import android.net.Uri;
import android.view.Menu;
import android.view.MenuItem;
import android.os.Environment;
import android.view.View;
import java.io.File;
import java.io.IOException;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import java.lang.String;
public class MainActivity extends ActionBarActivity {
String outputFile = "test.3gp";
private MediaRecorder myAudioRecorder;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
MediaRecorder myAudioRecorder = new MediaRecorder();
myAudioRecorder = new MediaRecorder();
// Uri target = Uri.parse(outputFile.getAbsolutePath());
myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
myAudioRecorder.setOutputFile(outputFile);
}
public void Start_Record(View v)
{
try {
myAudioRecorder.prepare();
myAudioRecorder.start();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
myAudioRecorder.stop();
myAudioRecorder.release();
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
I realise that this probably due to the fill pointer being set to NULL, however I am struggling to see how to initialize the file reference for this to vanish. I am getting th exception on mediaRecorderPrepare()
Here is the Exception thrown:
03-09 22:53:56.548 31836-31836/uk.co.spectralgear.spectralboost E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.IllegalStateException: Could not execute method of the activity
at android.view.View$1.onClick(View.java:4007)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
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:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.media.MediaRecorder.prepare()' on a null object reference
at uk.co..MainActivity.Start_Record(MainActivity.java:38)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at android.view.View$1.onClick(View.java:4002)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Any help would be greatly appreciated:)

PROBLEM:
Your class variable "myAudioRecord" is null when "Start_Record()" tries to use it:
Caused by: java.lang.NullPointerException:
Attempt to invoke virtual method 'void Android.media.MediaRecorder.prepare()' on a null object reference
SOLUTION: Delete this line from your "onCreate()" method:
public class MainActivity extends ActionBarActivity {
String outputFile = "test.3gp";
private MediaRecorder myAudioRecorder; // Your class variable: OK...
#Override
protected void onCreate(Bundle savedInstanceState) {
...
// MediaRecorder myAudioRecorder = new MediaRecorder(); // DELETE THIS LINE!!!
myAudioRecorder = new MediaRecorder(); // OK...
...
The declaration of "myAudioRecorder" inside onCreate() HIDES the outer declaration. So the outer (class-level) "myAudioRecorder" never gets initialized ... and your program dies with an NPE when "Start_Record()" tries to access it.
PS:
Please consider changing the method name to "start_Record()". Or better, "startRecord()". This is more consistent with Java naming conventions.

I think you are using stop() function while it was already stopped. Check your code and logic.

Volley Request Queue NullPointerException

I am trying to use the Volley library to query an xml api on the web with a search query provided by the user through a SearchWidget.
Whenever I enter a search string, the app crashes with a NullPointerException on adding the StringRequest to the RequestQueue.
Why is this happening?
I am already using Volley with a singleton pattern, as recommended in the Android Developer Guide.
Here is my search() function in the MainActivity.
public static final String TAG = "MYAPPTAG"
private RequestQueue mRequestQueue;
...
protected void onCreate(Bundle savedInstanceState) {
...
// Handle search intent
Intent intent = getIntent();
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
String query = intent.getStringExtra(SearchManager.QUERY);
search(query);
}
volley = MySingleton.getInstance(getApplicationContext());
mRequestQueue = volley.getRequestQueue();
}
...
private void search(String query) {
String xml = null;
String url = "http://www.acme.com/example.php?query=" + query;
StringRequest stringRequest = new StringRequest(Request.Method.POST, url,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
}
);
stringRequest.setTag(TAG);
mRequestQueue
.add(stringRequest); // the exception fires here
}
...
See below for the stack trace.
02-22 23:08:50.636 9856-9856/com.example.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.app, PID: 9856
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.app/com.example.app.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2212)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5146)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at com.example.app.MainActivity.search(MainActivity.java:121)
at com.example.app.MainActivity.onCreate(MainActivity.java:83)
at android.app.Activity.performCreate(Activity.java:5231)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2271)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1205)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:136)
            at android.app.ActivityThread.main(ActivityThread.java:5146)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:732)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:566)
            at dalvik.system.NativeStart.main(Native Method)

You are firing off a search before you've set the requestqueue from singleton.
So onCreate, you check for the Intent and then start a search before you've got a handle on the volley singleton and, in turn, the requestqueue. Try moving the volley code before the Intent check, like this:
volley = MySingleton.getInstance(getApplicationContext());
mRequestQueue = volley.getRequestQueue();
Intent intent = getIntent();
if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
String query = intent.getStringExtra(SearchManager.QUERY);
search(query);
}

Error getting content from .txt file from URL

URL scoreU = null;
try {
scoreU = new URL("http://m.uploadedit.com/b044/1422550899503.txt");
} catch (MalformedURLException e) {
e.printStackTrace();
}
BufferedReader in = null;
try {
in = new BufferedReader(
new InputStreamReader(
scoreU.openStream()));
} catch (IOException e) {
e.printStackTrace();
}
String inputLine;
try {
while ((inputLine = in.readLine()) != null)
System.out.println(inputLine);
} catch (IOException e) {
e.printStackTrace();
}
try {
in.close();
} catch (IOException e) {
e.printStackTrace();
}
That's my code related to getting the text from the URL. It's the first time I have done this and I cannot understand my mistake. (I had to surround almost everything with a try/catch .
ERROR:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wc.gap.worldcupfixture/com.wc.gap.worldcupfixture.MainActivity}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
at android.app.ActivityThread.access$800(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147)
at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:232)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:124)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:272)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:211)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:373)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:323)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:190)
at java.net.URL.openStream(URL.java:470)
at com.wc.gap.worldcupfixture.MainActivity.onCreate(MainActivity.java:102)
at android.app.Activity.performCreate(Activity.java:5933)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2251)
            at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360)
            at android.app.ActivityThread.access$800(ActivityThread.java:144)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            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:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
new InputStreamReader(scoreU.openStream()));

Android doesn't allow network requests on the main thread as it can cause UI unresponsiveness. Instead you have to do the work on a background thread, but this is pretty easy with an AsyncTask, for example:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// ...
// Start the task here
new URLDataLoader().execute(theURL);
}
private class URLDataLoader extends AsyncTask<URL, Void, String> {
#Override
protected String doInBackground(URL... params) {
URL theURL = params[0];
// Do your network stuff here to get the data
return theData;
}
#Override
protected void onPostExecute(String data) {
// Use the data here
}
}
}

Use this code:-
try {
URL url = new URL("http://m.uploadedit.com/b044/1422550899503.txt");
URLConnection urlConnection = url.openConnection();
HttpURLConnection connection = null;
connection = (HttpURLConnection) urlConnection;
BufferedReader in = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String urlString = "";
String current;
while ((current = in.readLine()) != null) {
urlString += current;
}
System.out.println(urlString);
} catch (IOException e) {
e.printStackTrace();
}