Android HttpUrlConnection getInputStream throws NullPointerException

Question

I am trying to download the image from this url:

https://hme_player_pictures.s3.amazonaws.com/test-512813ed3b83286c72f376c7-thumb100.jpg

here is stack trace:

03-21 12:58:04.040: W/System.err(7084): java.lang.NullPointerException
03-21 12:58:04.040: W/System.err(7084):     at libcore.net.http.HttpConnection$Address.hashCode(HttpConnection.java:343)
03-21 12:58:04.045: W/System.err(7084):     at java.util.HashMap.get(HashMap.java:298)
03-21 12:58:04.050: W/System.err(7084):     at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:67)
03-21 12:58:04.050: W/System.err(7084):     at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
03-21 12:58:04.050: W/System.err(7084):     at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:308)
03-21 12:58:04.055: W/System.err(7084):     at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.makeSslConnection(HttpsURLConnectionImpl.java:460)
03-21 12:58:04.055: W/System.err(7084):     at libcore.net.http.HttpsURLConnectionImpl$HttpsEngine.connect(HttpsURLConnectionImpl.java:432)
03-21 12:58:04.055: W/System.err(7084):     at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:282)
03-21 12:58:04.060: W/System.err(7084):     at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:232)
03-21 12:58:04.065: W/System.err(7084):     at libcore.net.http.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:273)
03-21 12:58:04.065: W/System.err(7084):     at libcore.net.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:168)
03-21 12:58:04.070: W/System.err(7084):     at libcore.net.http.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:270)
03-21 12:58:04.070: W/System.err(7084): ...

code:

URL imageUrl = new URL(url);
HttpURLConnection c = (HttpURLConnection)imageUrl.openConnection();
InputStream in = c.getInputStream(); // Nullpointer exception on this line, c is definitely not null, I debugged

Can't figure out why it is throwing NullPointerException. The above url does work in the browser.

score 3 · Answer 1 · answered Mar 21 '13 at 20:36

For what it's worth, I see a lot of errors from within the Android HTTP library. From Barcode Scanner I get stack traces from across about 35M people, and so I think I've seen one of everything. Here's all the weird stuff we just catch and swallow in the app, below. I recommend you work around it as a platform bug and fail gracefully.

https://code.google.com/p/zxing/source/browse/trunk/android/src/com/google/zxing/client/android/HttpHelper.java

  private static int safelyConnect(String uri, HttpURLConnection connection) throws IOException {
    try {
      connection.connect();
    } catch (NullPointerException npe) {
      // this is an Android bug: http://code.google.com/p/android/issues/detail?id=16895
      Log.w(TAG, "Bad URI? " + uri);
      throw new IOException(npe.toString());
    } catch (IllegalArgumentException iae) {
      // Also seen this in the wild, not sure what to make of it. Probably a bad URL
      Log.w(TAG, "Bad URI? " + uri);
      throw new IOException(iae.toString());
    } catch (SecurityException se) {
      // due to bad VPN settings?
      Log.w(TAG, "Restricted URI? " + uri);
      throw new IOException(se.toString());
    } catch (IndexOutOfBoundsException ioobe) {
      // Another Android problem? https://groups.google.com/forum/?fromgroups#!topic/google-admob-ads-sdk/U-WfmYa9or0
      Log.w(TAG, "Bad URI? " + uri);
      throw new IOException(ioobe.toString());
    }
    try {
      return connection.getResponseCode();
    } catch (NullPointerException npe) {
      // this is maybe this Android bug: http://code.google.com/p/android/issues/detail?id=15554
      Log.w(TAG, "Bad URI? " + uri);
      throw new IOException(npe.toString());
    } catch (NumberFormatException nfe) {
      // Again seen this in the wild for bad header fields in the server response!
      Log.w(TAG, "Bad server status? " + uri);
      throw new IOException(nfe.toString());
    }
  }

There are many similar issues. I'm just suggesting that it is not something your app has done wrong. In that case there's not much to do except work around it gracefully. — Sean Owen, Mar 21 '13 at 20:53
I have different stack trace than code.google.com/p/android/issues/detail?id=15554 I think it is something to do with https connection or amazons host url. Also `openConnection()` call succeeds but `getInputStream()` fails — Saqib, Mar 21 '13 at 20:54

score 1 · Accepted Answer · answered Mar 21 '13 at 21:29

1

As suspected issue was with host name of url of amazon s3.

so I changed

https://hme_player_pictures.s3.amazonaws.com/test-512813ed3b83286c72f376c7-thumb100.jpg

to

https://s3.amazonaws.com/hme_player_pictures/test-512813ed3b83286c72f376c7-thumb100.jpg

and it worked. My Java code is happy now!

answered Mar 21 '13 at 21:29

Saqib

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The problem might be the "_" (underscore) in the url: http://developers.facebook.com/bugs/436848366360282/ – José Castro Apr 20 '13 at 03:06

Android HttpUrlConnection getInputStream throws NullPointerException

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