A Writer that can be used to generate a String.
In most cases it is not necessary to use StringWriter. If the final
destination of the output is a file, use
FileWriter directly.
This will help to reduce memory usage. If you wish to transfer a feed to a
remote FTP, SFTP or WebDAV server, first write the feed to the file system
using FileWriter and optionally
CSVStreamWriter or
XMLStreamWriter, then upload the file with
FTPClient.putBinary(String, File),
SFTPClient.putBinary(String, File), or
WebDAVClient.put(String, File).
Note: when this class is used with sensitive data, be careful in persisting sensitive information to disk.