BufferedReader throwing exception and I don't know why

Question

public URL setUrl() throws Exception{
    System.out.println("1");
    URL iotd=new URL("http://www.nasa.gov/rss/image_of_the_day.rss");
    System.out.println("2");
    BufferedReader in=new BufferedReader(new InputStreamReader(iotd.openStream()));
    System.out.println("3");**//this never gets printed**

    //testing xml parser
    XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
    factory.setNamespaceAware(true);
    System.out.println("4");
    XmlPullParser xpp=factory.newPullParser();
    System.out.println("5");
    xpp.setInput(in);
    System.out.println("6");

    int eventType=xpp.getEventType();
    System.out.println(eventType+"!!!!!!!!!!!!!!!!");
    while(eventType!=XmlPullParser.END_DOCUMENT){
        if(eventType==XmlPullParser.START_DOCUMENT){
            System.out.println("start");
        }
    }

    in.close();
    return iotd;

}

The program never prints out "3" and theres so many warnings in logcat that it's pretty hard for me to decipher what's going on as I haven't used java in quite some time. Any ideas? I was following this code sample...

http://docs.oracle.com/javase/tutorial/networking/urls/readingURL.html

and was trying to modify it to parse xml but I haven't even gotten to test that part yet.

Here is all the warnings logcat gave me right after printing "2"

07-10 05:31:30.610: W/System.err(534): android.os.NetworkOnMainThreadException
07-10 05:31:30.621: W/System.err(534):  at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
07-10 05:31:30.621: W/System.err(534):  at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
07-10 05:31:30.621: W/System.err(534):  at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
07-10 05:31:30.621: W/System.err(534):  at java.net.InetAddress.getAllByName(InetAddress.java:220)
07-10 05:31:30.621: W/System.err(534):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:71)
07-10 05:31:30.621: W/System.err(534):  at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
07-10 05:31:30.621: W/System.err(534):  at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:351)
07-10 05:31:30.621: W/System.err(534):  at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:86)
07-10 05:31:30.621: W/System.err(534):  at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:308)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpEngine.connect(HttpEngine.java:303)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
07-10 05:31:30.630: W/System.err(534):  at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
07-10 05:31:30.630: W/System.err(534):  at java.net.URL.openStream(URL.java:462)
07-10 05:31:30.630: W/System.err(534):  at com.wajumbie.nasadailyimage.RssParse.setUrl(RssParse.java:14)
07-10 05:31:30.630: W/System.err(534):  at com.wajumbie.nasadailyimage.NasaDailyImage.onCreate(NasaDailyImage.java:29)
07-10 05:31:30.630: W/System.err(534):  at android.app.Activity.performCreate(Activity.java:4465)
07-10 05:31:30.630: W/System.err(534):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
07-10 05:31:30.630: W/System.err(534):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
07-10 05:31:30.630: W/System.err(534):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
07-10 05:31:30.640: W/System.err(534):  at android.app.ActivityThread.access$600(ActivityThread.java:123)
07-10 05:31:30.640: W/System.err(534):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
07-10 05:31:30.640: W/System.err(534):  at android.os.Handler.dispatchMessage(Handler.java:99)
07-10 05:31:30.640: W/System.err(534):  at android.os.Looper.loop(Looper.java:137)
07-10 05:31:30.640: W/System.err(534):  at android.app.ActivityThread.main(ActivityThread.java:4424)
07-10 05:31:30.640: W/System.err(534):  at java.lang.reflect.Method.invokeNative(Native Method)
07-10 05:31:30.640: W/System.err(534):  at java.lang.reflect.Method.invoke(Method.java:511)
07-10 05:31:30.640: W/System.err(534):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
07-10 05:31:30.640: W/System.err(534):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
07-10 05:31:30.640: W/System.err(534):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

The exception stack trace indicates that you are running this on the main thread. Is that the case? The main thread for Android development shouldn't have network or disk access. You should move you network operations to a thread, then the strict mode guard wont cause the exception.

Answer 2

try this way

 InputStream is=callWebservice("http://www.nasa.gov/rss/image_of_the_day.rss");
 BufferedReader in=new BufferedReader(new InputStreamReader(
            is, "iso-8859-1"));

where callWebservice is as shown below

 private InputStream callWebservice(String serviceURL) {
        HttpClient client=new DefaultHttpClient();
      HttpGet getRequest=new HttpGet();

      try {
          // construct a URI object
          getRequest.setURI(new URI(serviceURL));
      } catch (URISyntaxException e) {
          Log.e("URISyntaxException", e.toString());
      }

      // buffer reader to read the response
      BufferedReader in=null;
      // the service response
      HttpResponse response=null;
      try {
          // execute the request
          response = client.execute(getRequest);
      } catch (ClientProtocolException e) {
          Log.e("ClientProtocolException", e.toString());
      } catch (IOException e) {
          Log.e("IO exception", e.toString());
      }
      if(response!=null)
            try {
                return response.getEntity().getContent();
            } catch (IllegalStateException e) {
                // TODO Auto-generated catch block

                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block

                e.printStackTrace();
            }
        else
          return null;
        return null;

    }

Answer 3

There is a NetworkOnMainThreadException. Read this link for more information. And also this article.