無法連接到web服務通過android

Question

我目前無法連接到我的web服務在android上。我正在使用Jetty Web服務並使用ANT構建它。在我的筆記本電腦上，它完美運行並顯示來自我的數據庫的項但它似乎不會連接我的Android應用程序。附件是代碼和LOGCAT報告。

import org.apache.http.HttpResponse; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpGet; 
import org.apache.http.impl.client.DefaultHttpClient; 
import android.app.Activity; 
import android.os.Bundle; 
import android.widget.EditText; 
import android.widget.TextView; 
public class Android2Servlet extends Activity { 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.dbtest); 
TextView txtresp = (TextView)findViewById(R.id.servlet_response); 

String url = "http://(MY LAPTOPS IP):8085/DB"; 
HttpClient client = new DefaultHttpClient(); 
HttpGet request = new HttpGet(url); 
try{ 
System.out.println("About to execute"); 
HttpResponse response = client.execute(request); 
String helpedResp=HttpUnpack.request(response); 
System.out.println(helpedResp); 
txtresp.setText(helpedResp); 
System.out.println(response); 
}catch(Exception ex){ 
txtresp.setText("Failed!"); 
ex.printStackTrace(); 
} 
} } 

的HTTP文件解壓

import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import org.apache.http.HttpResponse; 
public class HttpUnpack { 
public static String request(HttpResponse response){ 
String result = ""; 
try{ InputStream in = response.getEntity().getContent(); 
BufferedReader reader = new BufferedReader(new InputStreamReader(in)); 
StringBuilder str = new StringBuilder(); 
String line = null; 
while((line = reader.readLine()) != null){ 
str.append(line + "\n"); 
} 
in.close(); 
result = str.toString(); 
}catch(Exception ex){ 
result = "Error retrieving response"; 
} 
return result; 
} 
} 

的HTTP拆封Android2Servlet不會引起任何錯誤，但文本框中只返回 「失敗！」。

logcat的文件

W/System.err(1282): android.os.NetworkOnMainThreadException 
W/System.err(1282):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099) 
W/System.err(1282):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84) 
W/System.err(1282):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127) 
W/System.err(1282):  at libcore.io.IoBridge.connect(IoBridge.java:112) 
W/System.err(1282):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192) 
W/System.err(1282):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459) 
W/System.err(1282):  at java.net.Socket.connect(Socket.java:842) 
W/System.err(1282):  at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119) 
W/System.err(1282):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144) 
W/System.err(1282):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164) 
W/System.err(1282):  at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119) 
W/System.err(1282):  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360) 
W/System.err(1282):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555) 
W/System.err(1282):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487) 
W/System.err(1282):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465) 
W/System.err(1282):  at myFood.myFood.Android2Servlet.onCreate(Android2Servlet.java:24) 
W/System.err(1282):  at android.app.Activity.performCreate(Activity.java:4465) 
W/System.err(1282):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
W/System.err(1282):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920) 
W/System.err(1282):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981) 
W/System.err(1282):  at android.app.ActivityThread.access$600(ActivityThread.java:123) 
W/System.err(1282):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147) 
W/System.err(1282):  at android.os.Handler.dispatchMessage(Handler.java:99) 
W/System.err(1282):  at android.os.Looper.loop(Looper.java:137) 
W/System.err(1282):  at android.app.ActivityThread.main(ActivityThread.java:4424) 
W/System.err(1282):  at java.lang.reflect.Method.invokeNative(Native Method) 
W/System.err(1282):  at java.lang.reflect.Method.invoke(Method.java:511) 
W/System.err(1282):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
W/System.err(1282):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
W/System.err(1282):  at dalvik.system.NativeStart.main(Native Method) 

任何反應將是極大的幫助。

問候。

編輯：

我現在已經刪除了網絡接入，並把它在另一個Java類。並稱之爲另一類。它仍然返回相同的錯誤。任何其他建議？

import org.apache.http.HttpResponse; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpGet; 
import org.apache.http.impl.client.DefaultHttpClient; 
public class androidconnectors { 

    public static final String main(String args[]) throws Exception { 


String txtresp = ""; 
try{ 
    String url = "http://(LAPTOPS IP):8085/Hello"; 
    HttpClient client = new DefaultHttpClient(); 
    HttpGet request = new HttpGet(url); 
System.out.println("About to execute"); 
HttpResponse response = client.execute(request); 
String helpedResp=HttpUnpack.request(response); // Http Unpack is not part of 
System.out.println(helpedResp); // of HttpClient library 
txtresp =(helpedResp); 
System.out.println(response); 
}catch(Exception ex){ 
    ex.printStackTrace(); 
} 
return txtresp; 
} 
} 

和android類。

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TextView; 

public class Settings extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.dbtest); 
     Button mybutton = (Button) findViewById(R.id.buttonpress); 
     mybutton.setOnClickListener(new View.OnClickListener() { 
      public void onClick(View view) { 
       TextView txtresp = (TextView)findViewById(R.id.servlet_response); 
      String[] args = null; 
      try { 
       String x = androidconnectors.main(args); 
       txtresp.setText(x); 
      } catch (Exception e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
       txtresp.setText("Failed"); 
      } 

      } 
     }); 
} 
} 

Answer 1

這似乎的基礎上，quick google search，既然蜂窩你不應該在你的應用程序的主線程中執行網絡訪問（以提高響應速度）。

如建議here創建另一個網絡訪問線程。

Answer 2

你不能這樣做網絡運營的UI線程更好地利用AsyncTask/Service/IntentService

NetworkOnMainThreadException

當應用程序試圖在其主線程執行 聯網運行時所引發的異常（自API 11以來）

Answer 3

要解決StrictMode問題，您需要使用下面的代碼在喲你的活動 -

static{ 
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build(); 
StrictMode.setThreadPolicy(policy); 
}