================================
Our use case
================================
We want to write files to a destination with both

• never overwrite existing files, but rename or move them before the new file is written
• avoid consumers reading in progress files, by writing to a temporary filename until the file is complete, and rename it afterwards.
  We think this is a very common use case. And Camel File and Sftp component have options to achieve that goal.
• "fileExist=Move" should prevent accidential overwriting of target files
• "tempPrefix/tempFileName" should prevent consumers from reading incomplete files
  But, unfortunately, when we combine these options, fileExist=Move doesn't work any more. In fact, the destination file will be overwritten.

The documentation states:

• "fileExist=Move": The Move option will move any existing files, before writing the target file. The Move option requires the corresponding moveExisting option to be configured as well.
  We use "fileExist=Move" and "moveExisting=arch${date:now:yyyyMMddHHmmssSSS}".
• tempPrefix: This option is used to write the file using a temporary name and then, after the write is complete, rename it to the real name.
• tempFileName: The same as tempPrefix option but offering a more fine grained control on the naming of the temporary filename.
  We use "tempFileName=__${file:onlyname}.tmp".
  The combiniation of these option is not restricted in any way. But it doesn't work.
  ================================