FileNotFoundException for HttpURLConnection in Ice Cream Sandwich
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28-10-2019 - |
Question
I have an Android app that works fine with Android 2.x and 3.x, but it fails when run on Android 4.x.
The problem is in this section of code:
URL url = new URL("http://blahblah.blah/somedata.xml");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setRequestMethod("GET");
urlConnection.setDoOutput(true);
urlConnection.connect();
InputStream inputStream = urlConnection.getInputStream();
When the application is running on Android 4.x, the getInputStream()
call results in a FileNotFoundException
. When the same binary is running on earlier versions of Android, it succeeds. The URLs also work fine in web browsers and with curl
.
Apparently something about HttpURLConnection
has changed in ICS. Does anybody have any idea what has changed, and/or what the fix might be?
Solution
Try removing the setDoOutput call. Taken from this blog: a blog
Edit: This is needed when using a POST call.
OTHER TIPS
A FileNotFoundException may also been thrown if the server returns a bad error code (e.g., 400 or 401). You can handle this as follows:
int responseCode = con.getResponseCode(); //can call this instead of con.connect()
if (responseCode >= 400 && responseCode <= 499) {
throw new Exception("Bad authentication status: " + responseCode); //provide a more meaningful exception message
}
else {
InputStream in = con.getInputStream();
//etc...
}
I Don't know why, but dealing manually with redirection resolves the problem.
connection.setInstanceFollowRedirects(false);
A little late but you can also verify the accepted content. You can add this line to accept all kinds of contents
urlConnection.setRequestProperty("Accept","*/*");