Google App Engine is not picking up Log4j

Question

Google App Engine does not create a file when using the file appender.

Answer 1

Google App Engine simply does not provide access to the file system. You can read from within your web-application, but you can't write anywhere. Those restrictions are the same for any framework you are using.

Most common example: you can upload file only with File Streaming API, without storing actual file in some temporary folder.