Android應用程序無法連接網絡服務器？

代碼Android應用程序無法連接網絡服務器？

private static final String TAG_SUCCESS = "success"; 

String URL_SERVER = "http://localhost/italk/servlet/login.ValidateUser"; 
//String URL_SERVER = "http://localhost/italk/servlet/login.ValidateUser"; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    inputUserName = (EditText) findViewById(R.id.txtUserName); 
    inputPassWord = (EditText) findViewById(R.id.txtPassWord); 

    btnLogin = (Button) findViewById(R.id.btnLogin); 
    btnLogin.setOnClickListener(new View.OnClickListener() { 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      //Neu login ->true 
      new doLogin().execute(); 
     } 
    }); 
} 

class doLogin extends AsyncTask<String, String, String> { 

    /** 
    * Getting product details in background thread 
    * */ 
    protected String doInBackground(String... params) { 

     // updating UI from Background Thread 
     runOnUiThread(new Runnable() { 
     public void run() { 
      // Check for success tag 
      String success; 
      try { 
       // Building Parameters 
       List<NameValuePair> params = new ArrayList<NameValuePair>(); 
       params.add(new BasicNameValuePair("user_name", inputUserName.getText().toString())); 
       params.add(new BasicNameValuePair("pass_word", inputPassWord.getText().toString())); 
       params.add(new BasicNameValuePair("db_name", "jdbc/ITTALKDS")); 
       // getting product details by making HTTP request 
       // Note that product details url will use GET request 
       JSONObject json = jsonParser.makeHttpRequest(
       URL_SERVER, "GET", params); 

       // check your log for json response 
       //Log.d("Single Product Details", json.toString()); 

       // json success tag 
       success = json.getString("result"); 
       if (success.equals("2")) {//Login successfully 
        pDialog = new ProgressDialog(MainActivity.this); 
        pDialog.setMessage("Login successfully..."); 
        Intent i = new Intent(getApplicationContext(), AlliTalk.class); 
        startActivity(i); 
       } else { 
        pDialog = new ProgressDialog(MainActivity.this); 
        pDialog.setMessage("Login failt..."); 
       } 
      } catch (JSONException e) { 
       e.printStackTrace(); 
      } 
     }); 

     return null; 
    } 
}

錯誤消息：

06-24 23:17:01.946: E/AndroidRuntime(7968): FATAL EXCEPTION: main 
06-24 23:17:01.946: E/AndroidRuntime(7968): android.os.NetworkOnMainThreadException 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at libcore.io.IoBridge.connect(IoBridge.java:112) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at java.net.Socket.connect(Socket.java:842) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at com.italk.JSONParser.makeHttpRequest(JSONParser.java:64) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at com.italk.MainActivity$doLogin$1.run(MainActivity.java:74) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at android.os.Handler.handleCallback(Handler.java:725) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at android.os.Handler.dispatchMessage(Handler.java:92) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at android.os.Looper.loop(Looper.java:137) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at android.app.ActivityThread.main(ActivityThread.java:5041) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at java.lang.reflect.Method.invoke(Method.java:511) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
06-24 23:17:01.946: E/AndroidRuntime(7968):  at dalvik.system.NativeStart.main(Native Method)

來源

2013-06-24 user1482495

這是因爲您不能在主線程上使用網絡服務。使用'AsyncTask'來完成這個... – Writwick

這個問題上取得了相當SO幾次已經解決了每次。

看文章AsyncTask

編輯：我沒有看到你的代碼在第一。您不應該在runOnUIThread中進行httprequests。堆棧跟蹤顯示「主線程上的網絡」。這意味着您應該在AsyncTask的doInBackground()方法中執行網絡部分，並從主線程更新UI。嘗試在AsyncTask處獲取值並將其返回到主線程，然後更新UI。看看之前鏈接的文章，以獲得清晰的想法。

來源

2013-06-24 16:32:43 Writwick