Return 'none' body filter if list of to-be-filtered JSON field-names is empty

[skjolber]

The Spring auto-configuration adds a body filter JacksonJsonFieldBodyFilter for JSON payloads without checking that there is actually some filtering to be performed.

Description

The LogbookProperties Obfuscate class jsonBodyFields field defaults to empty.

Add empty check, if so return noop filter.

Motivation and Context

Avoid unnecessary parse of JSON payloads.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

[skjolber]

Wiring of default empty obfuscate filters could be avoided entirely using a custom Conditional.

[kasmarian]

Thank you for the PR! I now wonder if the check for fields!=empty() should be done in JacksonJsonFieldBodyFilter itself. On the other hand, if after this change, people add it manually, they'd probably always have some fields to obfuscate.

[kasmarian]

ah, wait. We can't merge it as they commits are not signed. @skjolber would you be able forcepush only signed commits?

[skjolber]

@kasmarian better? First time signing commits.

[kasmarian]

Yes, looks good now, thank you!

[skjolber]

FYI this solves #1882 (did not see the issue until just now).

[kasmarian]

@msdousti could you re-approve?