problem

When there are messages rejected and they contain repeating groups (for example) that could not be parsed there is a message similar to this in the event log:
Rejecting invalid message: quickfix.FieldException: Out of order repeating group members, field=447: 8=FIX.4.4
9=142
35=AE
34=6
49=XXX
52=20171120-08:21:48.096
56=YYY
22=4
48=abc
55=[N/A]
552=1
2668=1
2669=0
2670=9
10=168

The log shows the message up to the point where the parsing failed. This makes the analysis difficult since one has to consult the message log additionally to the event log.

solution

Log the messageData (which is the original message String) instead of the parsed Message.