錯誤：連接到WebService時

我寫了一個程序並將它連接到mysql。我寫了一個Web服務類和使用HTTP客戶端，但我有運行時錯誤，請檢查我的代碼：錯誤：連接到WebService時

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 

public class WebService { 
    public static String readUrl(String url) { 
     HttpClient httpClient = new DefaultHttpClient(); 
     HttpPost httpPost = new HttpPost(url); 
     try { 
      HttpResponse httpResponse = httpClient.execute(httpPost); 
      InputStream inputStream = httpResponse.getEntity().getContent(); 
      String result = convertInputStreamToString(inputStream); 
      return result; 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    private static String convertInputStreamToString(InputStream inputStream) { 
     try { 
      BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream)); 
      StringBuilder stringBuilder = new StringBuilder(); 

      String line = ""; 
      while ((line = bufferedReader.readLine()) != null) { 
       stringBuilder.append(line); 
      } 
      return stringBuilder.toString(); 

     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 
} 



@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 


    String result = WebService.readUrl("http://localhost/note-server/"); 
    if (result != null) { 
     try { 
      JSONArray tasks = new JSONArray(result); 
      for(int i=0;i<tasks.length();i++){ 
       JSONObject task=tasks.getJSONObject(i); 
       Log.i("L",task.getString("task tilte")); 
      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 

    }

，這裏是錯誤代碼，我有：

at com.example.parisa.noteapplication.WebService.read Url(WebService.java:26) 


at com.example.parisa.noteapplication.MainActivity.on Create(MainActivity.java:47) 


    FATAL EXCEPTION: main 
    Process: com.example.parisa.noteapplication, PID: 29346 
    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.parisa.noteapplication/com.example.parisa.noteapplication.MainActivity}: android.os.NetworkOnMainThreadException 
    at android.app.ActivityThread.performLaunchActivity(A ctivityThread.java:2462)

和這裏

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
    setSupportActionBar(toolbar); 

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
    fab.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
        .setAction("Action", null).show(); 
     } 
    }); 


    String result = WebService.readUrl("http://localhost/note-server/"); 
    if (result != null) { 
     try { 
      JSONArray tasks = new JSONArray(result); 
      for(int i=0;i<tasks.length();i++){ 
       JSONObject task=tasks.getJSONObject(i); 
       Log.i("L",task.getString("task tilte")); 
      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 

    }

來源

2016-11-04 russel

你得到一個NetworkOnMainThreadException參見[如何解決android.os.NetworkOnMainThreadException？]（http://stackoverflow.com/questions/6343166/how-to-fix-android-os- networkonmainthreadexception） – peko

在單獨的線程中添加websevice。用戶AsyncTask類的 –

你必須單獨運行的線程上該readurl方法，

您無法將urlthread用於與webservices相關的事物。

在此先感謝

來源

2016-11-04 15:48:10

錯誤：連接到WebService時

回答

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