title: Download created file csv
body: <p>I am creating a file csv with opencsv library, but I have some little difficulties.
  I followed a tutorial on line:</p>
  
  <pre><code>private void exportProducts() {
  
      String OBJECT_LIST_SAMPLE = "C:/tmp/object-list-sample.csv";
  
       try (
               BufferedWriter  writer = Files.newBufferedWriter(Paths.get(OBJECT_LIST_SAMPLE));
  
                  CSVWriter csvWriter = new CSVWriter(writer,
                          CSVWriter.DEFAULT_SEPARATOR,
                          CSVWriter.NO_QUOTE_CHARACTER,
                          CSVWriter.DEFAULT_ESCAPE_CHARACTER,
                          CSVWriter.DEFAULT_LINE_END);
              ) {
                  String[] headerRecord = {"Name", "Email", "Phone", "Country"};
                  csvWriter.writeNext(headerRecord);
  
                  csvWriter.writeNext(new String[]{"Sundar Pichai ♥", "sundar.pichai@gmail.com", "+1-1111111111", "India"});
                  csvWriter.writeNext(new String[]{"Satya Nadella", "satya.nadella@outlook.com", "+1-1111111112", "India"});
  
              } catch (IOException e) {
                  LOG.error("", e);
              }
  
  }
  </code></pre>
  
  <p>All good, the file is created correctly, but I want extend this one. I mean</p>
  
  <ol>
  <li>I don't want use OBJECT_LIST_SAMPLE , but I want create a temp file (File.creteTempFile), use it to write the strings</li>
  <li>In the end, I want download directly this file, for the user.</li>
  </ol>
  
  <p>Please help me!</p>
  
  <p>Thanks</p>