Android - InputStreamReader не работает

Question

Я хочу получить строку с веб-сайта и преобразовать ее в массив. Он работает в eclipse, но если я хочу использовать его в Android-приложении, он не будет работать. Я знаю, это должна быть глупая ошибка, но я не знаю, где она.

InternetHandler:

package de.blender4me.einkaufsliste; 

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.URL; 
import java.util.regex.Pattern; 

public class internetHandler { 

//Einkaufsplaner-API aufrufen 
    public static String[] getList(){ 

     InputStream is = null; 

     try 
     { 
      URL url = new URL("https://einkaufsplaner.blender4me.de/api.php?name=Username&pass=SuperSecretPass&addValue=&removeValue="); 
      BufferedReader in = new BufferedReader(
      new InputStreamReader(url.openStream())); 

      String Values = null; 

      for(int i = 0; i < 4; ++i){ 
       Values = in.readLine(); 
      } 
      in.close(); 

      String[] List = Values.split(Pattern.quote(";")); 
      return List; 

     } 
     catch (Exception e) { 
      e.printStackTrace(); 
     } 
     finally { 
      if (is != null) 
      try { is.close(); } catch (IOException e) { } 
     } 
     String[] error = {"error"}; 
     return error; 
    } 
} 

Главная

package de.blender4me.einkaufsliste; 

import android.app.Activity; 
import android.app.AlertDialog; 
import android.content.DialogInterface; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.ListView; 


public class MainActivity extends Activity { 

//Widgets 
Button addItem; 



    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     //listView 
     populateListView(); 

     //register Widgets 
     addItem =(Button) findViewById(R.id.addItem); 

     addItem.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       openDialog(); 
      } 
     }); 
    } 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.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(); 
    if (id == R.id.action_settings) { 
     return true; 
    } 
    return super.onOptionsItemSelected(item); 
} 

//Alert 
public void openDialog(){ 
    AlertDialog.Builder alert = new AlertDialog.Builder(this); 

    alert.setTitle("Zur Einkaufsliste hinzufügen"); 
    alert.setMessage(" "); 

    // Set an EditText view to get user input 
    final EditText input = new EditText(this); 
    alert.setView(input); 

    alert.setPositiveButton("Bestätigen", new DialogInterface.OnClickListener() { 
    public void onClick(DialogInterface dialog, int whichButton) { 
     String value = input.getText().toString(); 
     // Do something with value! 
     } 
    }); 

    alert.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int whichButton) { 
     // Canceled. 
     } 
    }); 

    alert.show(); 
} 

//listView erstellen 
private void populateListView() { 
     // Liste auslesen 
     String[] values = internetHandler.getList(); 

     //Liste konvertieren 
     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
       R.layout.listview_item, //Genutztes Layout 
       values); //Genutzter Array 

     //listView einstellen 
     ListView list = (ListView) findViewById(R.id.listView); 
     list.setAdapter(adapter); 
    } 
} 

Manifest

<uses-sdk 
    android:minSdkVersion="14" 
    android:targetSdkVersion="19" /> 
<uses-permission android:name="android.permission.INTERNET"/> 
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/> 


<application 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@android:style/Theme.Holo.Light.NoActionBar.Fullscreen" 

>

  <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
</application> 

Он всегда возвращает ошибку-массив, но ИДК почему: C

LogCat:

11-07 15: 18: 24.425: E/Trace (642): файл с открытием ошибки: нет такого файла или каталога (2) 11-07 15: 18: 24.925: W/System.err (642) : android.os.NetworkOnMainThreadException 11-07 15: 18: 24,925: Вт/System.err (642): в android.os.StrictMode $ AndroidBlockGuardPolicy.onNetwork (StrictMode.java:1117) 11-07 15: 18: 24.935: W/System.err (642): at java.net.InetAddress.lookupHostByName (InetAddress.java:385) 11-07 15: 18: 24.935: W/System.err (642): at java.net.InetAddress.getAllByNameImpl (InetAddress.java:236) 11-07 15: 18: 24.935: W/System.err (642): at java.net.InetAddress.getAllByName (InetAddress.java:214) 11 -07 15: 18: 24.935: W/System.err (642): at libcore.net.http.HttpConnection. (HttpConnection.java:70) 11-07 15: 18: 24.935: W/System.err (642)): at libcore.net.http.HttpConnection. (HttpConnection.java:50) 11-07 15: 18: 24.935: W/System.err (642): at Адрес сайта libcore.net.http.HttpConnection $. connect (HttpConnection.java:341) 11-07 15: 18: 24.935: W/System.err (642): at libcore.net.http.HttpConnectionPool.get (HttpConnectionPool.java:87) 11-07 15 : 18: 24.935: W/System.err (642): at libcore.net.http.HttpConnection.connect (HttpConnection.java:128) 11-07 15: 18: 24.935: W/System.err (642) : at libcore.net.http.HttpEngine.openSocketConnection (Http Engine.java:315) 11-07 15: 18: 24.945: W/System.err (642): at libcore.net.http.HttpsURLConnectionImpl $ HttpsEngine.makeSslConnection (HttpsURLConnectionImpl.java:461) 11-07 15 : 18: 24.945: W/System.err (642): at libcore.net.http.HttpsURLConnectionImpl $ HttpsEngine.connect (HttpsURLConnectionImpl.java:433) 11-07 15: 18: 24.945: W/System.err (642): at libcore.net.http.HttpEngine.sendSocketRequest (HttpEngine.java:289) 11-07 15: 18: 24.945: W/System.err (642): at libcore.net.http.HttpEngine.sendRequest (HttpEngine.java:239) 11-07 15: 18: 24.945: W/System.err (642): at libcore.net.http. HttpURLConnectionImpl.getResponse (HttpURLConnectionImpl.java:273) 11-07 15: 18: 24,945: Вт/System.err (642): в libcore.net.http.HttpURLConnectionImpl.getInputStream (HttpURLConnectionImpl.java:168) 11- 07 15: 18: 24.945: W/System.err (642): at libcore.net.http.HttpsURLConnectionImpl.getInputStream (HttpsURLConnectionImpl.java:271) 11-07 15: 18: 24.955: W/System.err (642): at java.net.URL.openStream (URL.java:462) 11-07 15: 18: 24.955: W/System.err (642): at de.blender4me.einkaufsliste.internetHandler.getList (internetHandler.j ava: 21) 11-07 15: 18: 24.955: W/System.err (642): at de.blender4me.einkaufsliste.MainActivity.populateListView (MainActivity.java:100) 11-07 15: 18: 24.955 : W/System.err (642): at de.blender4me.einkaufsliste.MainActivity.onCreate (MainActivity.java:37) 11-07 15: 18: 24.955: W/System.err (642): at android .app.Activity.performCreate (Activity.java:5008) 11-07 15: 18: 24.955: W/System.err (642): at android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1079) 11 -07 15: 18: 24.955: W/System.err (642): at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2023) 11-07 15: 18: 24.965: W/System.err (642)): по адресу: android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2084) 11-07 15: 18: 24.965: W/System.err (642): at android.app.ActivityThread.access $ 600 (ActivityThread.java:130) 11-07 15: 18: 24.965: W/System.err (642): at android.app.ActivityThread $ H.handleMessage (ActivityThread.java:1195) 11-07 15: 18: 24.965: W/System.err (642): at android.os.Handler.dispatchMessage (Handler.java:99) 11-07 15: 18: 24.965: W/System.err (642): at android.os.Looper. loop (Looper.java:137) 11-07 15: 18: 24.965: W/System.err (642): at android.app.ActivityThread.main (ActivityThread.java:4745) 11-07 15:18 : 24.965: W/System.err (642): у java. lang.reflect.Method.invokeNative (родной метод) 11-07 15: 18: 24.965: W/System.err (642): at java.lang.reflect.Method.invoke (Method.java:511) 11- 07 15: 18: 24.975: W/System.err (642): at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run (ZygoteInit.java:786) 11-07 15: 18: 24.975: W /System.err (642): at com.android.internal.os.ZygoteInit.main (ZygoteInit.java:553) 11-07 15: 18: 24.975: W/System.err (642): at dalvik .system.NativeStart.main (Native Method) 11-07 15: 18: 26.455: D/gralloc_goldfish (642): Эмулятор без эмуляции графического процессора.

Answer 1

Ваша проблема здесь (в StackTrace):

android.os.NetworkOnMainThreadException

Вы делаете запрос в MainThread, который с Android использованы без разрешения, чтобы избежать тяжелых обработок на UI (делая это будет блокировать пользовательский интерфейс).

Вместо этого используйте AsyncTask.

Пример AsyncTask начать с чего-то:

private class LongOperation extends AsyncTask<Void, Void, String> { 

    @Override 
    protected String doInBackground(Void... params) { 
     InternetHandler ih = new InternetHandler(); 
     String[] values = ih.getList(); 
    } 

    @Override 
    protected void onPostExecute(String result) { 
     //Liste konvertieren 
     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, 
      R.layout.listview_item, //Genutztes Layout 
      values); //Genutzter Array 

     //listView einstellen 
     ListView list = (ListView) findViewById(R.id.listView); 
     list.setAdapter(adapter); 
    } 

    @Override 
    protected void onPreExecute() {} 

    @Override 
    protected void onProgressUpdate(Void... values) {} 
} 

Позвоните ему:

LongOperation lo = new LongOperation(); 
lo.execute(); 

Answer 2

Проблема: вы пытаетесь выполнить HTTP-запрос в потоке пользовательского интерфейса приложения.

Вы должны сделать это внутри AsyncTask.