If you want to ingest the entire file as a single event then use a multiline codec that never matches and a timeout
codec => multiline { pattern => "^Spalanzani" negate => true what => previous auto_flush_interval => 1 }
If you have multiple objects which are pretty-printed, so that a line just containing } indicates the end of an object use
codec => multiline { pattern => "^}" negate => true what => next auto_flush_interval => 1 }