capitano666 capitano666 - 2 days ago 5
HTTP Question

HttpURLConnection downloaded file name

Is it possible to get the name of a file downloaded with HttpURLConnection?

URL url = new URL("http://somesite/getFile?id=12345");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setAllowUserInteraction(false);
conn.setDoInput(true);
conn.setDoOutput(true);
conn.connect();
InputStream is = conn.getInputStream();


In the example above I cannot extract the file name from the URL, but the server will send me the file name in some way.

Answer

You could use HttpURLConnection.getHeaderField(String name) to get the Content-Disposition header, which is normally used to set the file name:

String raw = conn.getHeaderField("Content-Disposition");
// raw = "attachment; filename=abc.jpg"
if(raw != null && raw.indexOf("=") != -1) {
    String fileName = raw.split("=")[1]; //getting value after '='
} else {
    // fall back to random generated file name?
}

As other answer pointed out, the server might return invalid file name, but you could try it.

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