HttpURLConnection打开跟踪文件时出错：没有这样的文件或目录

Question

我正在尝试连接到一个URL以获取geopoints在我的android应用程序的mapview中绘制路线。但是，当我尝试连接到URL以获取点时，出现此错误。

URL url = new URL("http://maps.google.com/maps?f=d&hl=en&saddr=59.690289,16.60868&daddr=59.6,16.60868&ie=UTF8&0&om=0&output=kml"); 
Log.d("log","url: " + url); 
HttpURLConnection urlConnection=(HttpURLConnection)url.openConnection();   urlConnection.setRequestMethod("GET"); 
urlConnection.setDoOutput(true); 
urlConnection.setDoInput(true); 
urlConnection.connect(); 
Log.d("log","connected"); 

我有以下我的清单

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

我在Eclipse 4.2.2在Mac OSX狮子使用模拟器运行此。

感谢您的帮助！

编辑

对不起，我离开了一些重要的信息，这里有我的所有权限在我的清单

<uses-permission android:name="com.vogella.android.locationapi.maps.permission.MAPS_RECEIVE" /> 
<uses-permission android:name="android.permission.INTERNET" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
<uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" /> 
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> 
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 

EDIT 2

这里是完整的错误

04-07 00:24:46.842: E/AndroidRuntime(7280): FATAL EXCEPTION: main 
04-07 00:24:46.842: E/AndroidRuntime(7280): java.lang.RuntimeException: Unable to start activity ComponentInfo{markustenghamn.sfsfum/markustenghamn.sfsfum.MapHandlerActivity}: android.os.NetworkOnMainThreadException 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread.access$600(ActivityThread.java:141) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.os.Handler.dispatchMessage(Handler.java:99) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.os.Looper.loop(Looper.java:137) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread.main(ActivityThread.java:5041) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at java.lang.reflect.Method.invokeNative(Native Method) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at java.lang.reflect.Method.invoke(Method.java:511) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at dalvik.system.NativeStart.main(Native Method) 
04-07 00:24:46.842: E/AndroidRuntime(7280): Caused by: android.os.NetworkOnMainThreadException 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1117) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at java.net.InetAddress.getAllByName(InetAddress.java:214) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:70) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpEngine.connect(HttpEngine.java:311) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at markustenghamn.sfsfum.MapHandlerActivity.DrawPath(MapHandlerActivity.java:166) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at markustenghamn.sfsfum.MapHandlerActivity.callMap(MapHandlerActivity.java:126) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at markustenghamn.sfsfum.MapHandlerActivity.onCreate(MapHandlerActivity.java:89) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.Activity.performCreate(Activity.java:5104) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144) 
04-07 00:24:46.842: E/AndroidRuntime(7280):  ... 11 more 
04-07 00:24:49.343: E/Trace(7297): error opening trace file: No such file or directory (2) 

Answer 1

当您试图在主应用程序线程上访问Internet时，您会收到此异常。您需要在不同的线程中完成所有网络活动。您可以使用AsyncTask来完成此操作。

这样做是为了让应用程序保持响应，即使阻塞了对网络的呼叫。您可能还需要进一步阅读here。