HttpURLConnection java.io.FileNotFoundException

Question

The code below works great if I connect to what seems to be Apache servers, however when I try to connect to my .Net server it throws an error. I am guessing it is a header

Answer 1

I faced an issue, where executing a HEAD-Request threw a FileNotFoundException.
The reason is, that a response to a HEAD does not have a body and therefore a call to getInputStream throws a FileNotFoundException.

So if you are executing a HEAD, you should not try to get the InputStream.

Answer 2

Had the same problem, solved like you said:

urlConnection.setDoOutput(false);

Note that you must set it to false because it's true by default.
Note that you must set it to false because Volley HurlStack was setting it to true.
Take care ;)

EDIT: I've just checked the code and by default it's false as @Abraham Philip said. But I had to set it to false because if I called getDoOutput() it was returning true. I found that Volley HurlStack was setting it to true. So, my conclusion is, setDoOutput to false and it will work.

package java.net;
public abstract class URLConnection {
...

    /**
     * Specifies whether this {@code URLConnection} allows sending data.
     */
    protected boolean doOutput;

...
    public boolean getDoOutput() {
        return doOutput;
    }

    public void setDoOutput(boolean newValue) {
        checkNotConnected();
        this.doOutput = newValue;
    }

Answer 3

You can get a FileNotFoundException from HttpUrlConnection (and OkHttpClient) if your server returns >= HTTPStatus.BAD_REQUEST (400). You should check the status code first to check what stream you need to read.

int status = connection.getResponseCode();

if(status >= HttpStatus.SC_BAD_REQUEST)
    in = connection.getErrorStream();
else
    in = connection.getInputStream();

HttpStatus deprecated. Latest syntax seems to be:

InputStream inputStream;
int status = urlConnection.getResponseCode();

if (status != HttpURLConnection.HTTP_OK)  {
    inputStream = urlConnection.getErrorStream();
}
else  {
    inputStream = urlConnection.getInputStream();
}