我想從網站檢索數據,我的應用程序不斷崩潰。我已將問題定位到openStream()命令。我正在使用的類定義如下。我無法弄清楚我做錯了什麼。任何意見表示讚賞。Android的url.openStream()不工作
private class MyAsyncTask extends AsyncTask<Void, Void, Void>{
//execute on background (out of the UI thread)
protected void doInBackground() {
URL url = null;
try {
url = new URL("URL is in here");
BufferedInputStream bis = new BufferedInputStream(url.openStream());
byte[] buffer = new byte[1024];
StringBuilder sb = new StringBuilder();
int bytesRead = 0;
while((bytesRead = bis.read(buffer)) > 0) {
String text = new String(buffer, 0, bytesRead);
sb.append(text);
}
bis.close();
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
@Override
protected Void doInBackground(Void... arg0) {
// TODO Auto-generated method stub
return null;
}
}
我在我的清單文件中有Internet權限。再次感謝任何幫助。
以下是在logcat中顯示的錯誤。
11月7日至11日:26:31.110:E/AndroidRuntime(9259):致命異常:主 11月7日至11日:26:31.110:E/AndroidRuntime(9259):了java.lang.RuntimeException:無法開始活動ComponentInfo {com.example.annarbormap/com.example.annarbormap.MapActivity}:android.os.NetworkOnMainThreadException 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2246) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2296) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.app.ActivityThread.access $ 700(ActivityThread.java:151) 07-11 11:26:31.110:E/Andr oidRuntime(9259):at android.app.ActivityThread $ H.handleMessage(ActivityThread.java:1281) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.os.Handler.dispatchMessage(Handler。 java:99) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.os.Looper.loop(Looper.java:137) 07-11 11:26:31.110:E/AndroidRuntime 9259):at android.app.ActivityThread.main(ActivityThread.java:5293) 07-11 11:26:31.110:E/AndroidRuntime(9259):at java.lang.reflect.Method.invokeNative(Native Method) 07-11 11:26:31.110:E/AndroidRuntime(9259):在java.lang.reflect.Method.invoke(Method.java:511) 07-11 11:26:31.110:E/AndroidRuntime(9259): at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:1102) 07-11 11:26:31.110:E/AndroidRuntime(9259):at com.android.inte rnal.os.ZygoteInit.main(ZygoteInit.java:869) 07-11 11:26:31.110:E/AndroidRuntime(9259):at dalvik.system.NativeStart.main(Native Method) 07-11 11:26 :31.110:E/AndroidRuntime(9259):導致:android.os.NetworkOnMainThreadException 07-11 11:26:31.110:E/AndroidRuntime(9259):在android.os.StrictMode $ AndroidBlockGuardPolicy.onNetwork(StrictMode.java: 1118) 07-11 11:26:31.110:E/AndroidRuntime(9259):at java.net.InetAddress.lookupHostByName(InetAddress.java:385) 07-11 11:26:31.110:E/AndroidRuntime(9259) :at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236) 07-11 11:26:31.110:E/AndroidRuntime(9259):at java.net.InetAddress.getAllByName(InetAddress.java:214) 07 -11 11:26:31.110:E/AndroidRuntime(9259):在libcore.net.http.HttpConnection。(HttpConnection。 java:70) 07-11 11:26:31.110:E/AndroidRuntime(9259):at libcore.net.http.HttpConnection。(HttpConnection.java:50) 07-11 11:26:31.110:E/AndroidRuntime (9259):在libcore.net.http.HttpConnection $ Address.connect(HttpConnection.java:340) 07-11 11:26:31.110:E/AndroidRuntime(9259):位於libcore.net.http.HttpConnectionPool.get (HttpConnectionPool.java:87) 07-11 11:26:31.110:E/AndroidRuntime(9259):at libcore.net.http.HttpConnection.connect(HttpConnection.java:128) 07-11 11:26:31.110 :E/AndroidRuntime(9259):在libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316) 07-11 11:26:31.110:E/AndroidRuntime(9259):在libcore.net.http.HttpsURLConnectionImpl $ HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:461) 07-11 11:26:31.110:E/AndroidRuntime(9259):在libcore.net.http.HttpsURLConnectionImpl $ HttpsEngine.connect(HttpsURLConnectionImpl.java:433) 07-11 11:26:31。110:E/AndroidRuntime(9259):在libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290) 07-11 11:26:31.110:E/AndroidRuntime(9259):在libcore.net.http。 HttpEngine.sendRequest(HttpEngine.java:240) 07-11 11:26:31.110:E/AndroidRuntime(9259):在libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:282) 07-11 11: 26:31.110:E/AndroidRuntime(9259):在libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:177) 07-11 11:26:31.110:E/AndroidRuntime(9259):位於libcore.net。 (HttpsURLConnectionImpl.java:271) 07-11 11:26:31.110:E/AndroidRuntime(9259) 26:31.110:E/AndroidRuntime(9259):at com.example.annarbormap.MapActivity $ MyAsyncTask.doInBackground(M apActivity.java:77) 07-11 11:26:31.110:E/AndroidRuntime(9259):at com.example.annarbormap.MapActivity.onCreate(MapActivity.java:48) 07-11 11:26:31.110: E/AndroidRuntime(9259):在android.app.Activity.performCreate(Activity.java:5250) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.app.Instrumentation.callActivityOnCreate(Instrumentation。 java:1097) 07-11 11:26:31.110:E/AndroidRuntime(9259):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2210) 07-11 11:26:31.110:E/AndroidRuntime 9259):...... 11多個
請提供logcat或錯誤消息。 –