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POOnly download file if updated?
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copied!<p>I'm using the code below to download a file. However I only want to download if the remote file is newer then the locally stored (if there is one). Can I somehow use the if-modefied-since http header? How can I update my code to archive my goal?</p> <pre><code>private class DownloadFile extends AsyncTask<String, Integer, String> { @Override protected void onPreExecute() { super.onPreExecute(); mProgressDialog.show(); } @Override protected String doInBackground(String... sUrl) { try { URL url = new URL(sUrl[0]); URLConnection connection = url.openConnection(); connection.connect(); // this will be useful so that you can show a typical 0-100% progress bar int fileLength = connection.getContentLength(); // download the file InputStream input = new BufferedInputStream(url.openStream()); OutputStream output = new FileOutputStream(path); byte data[] = new byte[1024]; long total = 0; int count; while ((count = input.read(data)) != -1) { total += count; publishProgress((int) (total * 100 / fileLength)); output.write(data, 0, count); } output.flush(); output.close(); input.close(); } catch(MalformedURLException e) { e.printStackTrace(); } catch(FileNotFoundException e) { e.printStackTrace(); } catch(IOException e) { e.printStackTrace(); } return null; } @Override protected void onPostExecute(String result) { super.onPostExecute(result); mProgressDialog.dismiss(); // TODO: here file is downloaded and we are ready to process it. } @Override protected void onProgressUpdate(Integer... progress) { super.onProgressUpdate(progress); mProgressDialog.setProgress(progress[0]); } } </code></pre> <p>I've updated my code to look like this...</p> <pre><code> @Override protected String doInBackground(String... sUrl) { long lastModified = new File(path).lastModified(); try { URL url = new URL(sUrl[0]); URLConnection connection = url.openConnection(); connection.connect(); if(lastModified != 0) { connection.setIfModifiedSince(lastModified); } // this will be useful so that you can show a typical 0-100% progress bar int fileLength = connection.getContentLength(); ... </code></pre> <p>Any good ideas regarding how to actually test this? The while loop shouldn't run if the file isn't newer, right?</p>

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