title: Custom implementation of InputStream
body: <p>To send data to a file on my FTP server, I need to create a custom InputStream implementation that reads database data row by row, converts it to CSV and publishes it via its read() methods: from the database, I get a <code>List&lt;Application&gt;</code> object with the data. For each <code>Application</code> object, I want to create a line in the CSV file.</p>
  
  <p>My idea is to load all the data in the constructor and then override the read method. Do I need to override all InputStream's methods? I tried googling for some examples but didn't succeed - could you eventually give me a link to one?</p>