Android JAVA HTTP GET请求-NetworkOnMainThreadException，带有空消息

我有一部分代码可以从GPS获取数据，并将其保存回API

try{ 

        String Lat = URLEncoder.encode(Double.toString(loc.getLatitude()), "UTF-8");
        String Lng = URLEncoder.encode(Double.toString(loc.getLongitude()), "UTF-8");

        String currentLocationText = "My current location is: " + "Lat = " + Lat + "Lng = " + Lng;

        Log.d(LOG_TAG, currentLocationText);

        String urlString = "http://api/?lat="+Lat+"&lng="+Lng;

          URL url = new URL(urlString);
          URLConnection conn = url.openConnection();
          InputStream is = conn.getInputStream();

          StringWriter writer = new StringWriter();
          IOUtils.copy(is, writer, "UTF-8");
          String theString = writer.toString();

          Log.d(LOG_TAG, "Server response: ."+ theString);
      } catch (Exception e) {
          Log.d(LOG_TAG, "Exception: "+ e.getMessage());
      }

但是，在运行时，我在日志中收到：

"Exception: null"

在我的清单文件中，我将：

 <uses-permission android:name="android.permission.INTERNET" /> 

抱歉，如果它看起来很混乱（异常处理程序），我是PHP开发人员，这是我的第一步：）

我怎么知道是什么问题？我是否可以改进异常消息以了解发生了什么

编辑： 找到堆栈的痕迹了吗

01-16 21:47:14.759: D/MyLocationListener(2041): Exception: null
01-16 21:47:14.784: D/MyLocationListener(2041): Stack trace: android.os.NetworkOnMainThreadException
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1144)
01-16 21:47:14.784: D/MyLocationListener(2041):     at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
01-16 21:47:14.784: D/MyLocationListener(2041):     at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
01-16 21:47:14.784: D/MyLocationListener(2041):     at java.net.InetAddress.getAllByName(InetAddress.java:214)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282)
01-16 21:47:14.784: D/MyLocationListener(2041):     at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177)
01-16 21:47:14.784: D/MyLocationListener(2041):     at com.example.gps_tracker.MyLocationListener.onLocationChanged(MyLocationListener.java:44)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.location.LocationManager$ListenerTransport._handleMessage(LocationManager.java:255)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.location.LocationManager$ListenerTransport.access$000(LocationManager.java:184)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.location.LocationManager$ListenerTransport$1.handleMessage(LocationManager.java:200)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.os.Handler.dispatchMessage(Handler.java:99)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.os.Looper.loop(Looper.java:176)
01-16 21:47:14.784: D/MyLocationListener(2041):     at android.app.ActivityThread.main(ActivityThread.java:5419)
01-16 21:47:14.784: D/MyLocationListener(2041):     at java.lang.reflect.Method.invokeNative(Native Method)
01-16 21:47:14.784: D/MyLocationListener(2041):     at java.lang.reflect.Method.invoke(Method.java:525)
01-16 21:47:14.784: D/MyLocationListener(2041):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
01-16 21:47:14.784: D/MyLocationListener(2041):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
01-16 21:47:14.784: D/MyLocationListener(2041):     at dalvik.system.NativeStart.main(Native Method)

01-16 21:47:14.759:D/MyLocationListener（2041）：异常：null
01-16 21:47:14.784:D/MyLocationListener（2041）：堆栈跟踪：android.os.NetworkOnMainThreadException
01-16 21:47:14.784:D/MyLocationListener（2041）：在android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork（StrictMode.java:1144）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于java.net.InetAddress.lookupHostByName（InetAddress.java:385）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于java.net.InetAddress.getAllByNameImpl（InetAddress.java:236）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于java.net.InetAddress.getAllByName（InetAddress.java:214）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpConnection。（HttpConnection.java:70）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpConnection。（HttpConnection.java:50）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpConnection$Address.connect（HttpConnection.java:340）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpConnectionPool.get（HttpConnectionPool.java:87）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpConnection.connect（HttpConnection.java:128）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpEngine.openSocketConnection（HttpEngine.java:316）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpEngine.connect（HttpEngine.java:311）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpEngine.sendSocketRequest（HttpEngine.java:290）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpEngine.sendRequest（HttpEngine.java:240）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpURLConnectionImpl.getResponse（HttpURLConnectionImpl.java:282）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于libcore.net.http.HttpURLConnectionImpl.getInputStream（HttpURLConnectionImpl.java:177）
01-16 21:47:14.784:D/MyLocationListener（2041）：在com.example.gps_tracker.MyLocationListener.onLocationChanged（MyLocationListener.java:44）
01-16 21:47:14.784:D/MyLocationListener（2041）：在android.location.LocationManager$ListenerTransport.\u handleMessage（LocationManager.java:255）
01-16 21:47:14.784:D/MyLocationListener（2041）：在android.location.LocationManager$ListenerTransport.access$000（LocationManager.java:184）
01-16 21:47:14.784:D/MyLocationListener（2041）：在android.location.LocationManager$ListenerTransport$1.handleMessage（LocationManager.java:200）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于android.os.Handler.dispatchMessage（Handler.java:99）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于android.os.Looper.loop（Looper.java:176）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于android.app.ActivityThread.main（ActivityThread.java:5419）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于java.lang.reflect.Method.Invokenactive（本机方法）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于java.lang.reflect.Method.invoke（Method.java:525）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run（ZygoteInit.java:1046）
01-16 21:47:14.784:D/MyLocationListener（2041）：位于com.android.internal.os.ZygoteInit.main（ZygoteInit.java:862）
01-16 21:47:14.784:D/MyLocationListener（2041）：在dalvik.system.NativeStart.main（本机方法）

我想我需要阅读并充分理解：

---

在web上使用AsyncTask获取和发布请求

您应该使用async task完成所有网络任务。目前，您的做法是阻止ui线程，这是不允许的。这就是为什么你会出错

---

查看有关如何使用AsyncTask的内容：

记录异常的完整堆栈跟踪和/或使用调试器逐步检查代码。@MattBall谢谢。我仍然没有答案，但至少有一些东西要读：）只是为了证实。按照那条线索的答案：它确切地说明了你提供了什么链接，所有的问题都消失了。