Fix #453: Add logging-support module with StructuredArgumentsConverter

[vita-kotacka]

Summary

Adds a new logging-support module to java-core with a Logback PatternConverter that makes StructuredArguments.kv() fields visible in plain-text log output (dev and test environments).

Closes #453

Problem

logstash-logback-encoder's kv() arguments are JSON-only by default — without a {} placeholder in the message, structured key-value pairs are invisible in plain Logback text output. This creates a poor developer experience when running tests or the application locally.

Solution

New StructuredArgumentsConverter (extends ClassicConverter) reads the logging event's argument array, picks out StructuredArgument instances, and renders them as {key=value, ...} prepended with a space and appended to the log line. Returns empty string when no structured arguments are present — no trailing whitespace.

Note

This converter is intended exclusively for dev and test log configurations (logback-dev.xml, logback-test.xml). Production configs use LogstashEncoder which already serialises kv() as JSON fields — no production change needed.

Usage

<conversionRule conversionWord="sa"
    converterClass="com.wultra.core.logging.logback.StructuredArgumentsConverter"/>
<pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%sa%n</pattern>

Example output:

10:35:22.123 [main] INFO  c.w.EnrollmentService - action: createIdentity, state: succeeded {processId=abc-123, identityVerificationId=def-456}

Changes

File	Change
pom.xml	Added <module>logging-support</module>, <logstash.version>9.0</logstash.version>
bom/pom.xml	Added logging-support to BOM
logging-support/pom.xml	New module; logstash-logback-encoder as regular transitive dependency
StructuredArgumentsConverter.java	New converter class
StructuredArgumentsConverterTest.java	4 unit tests
Changelog.md	Added entry for #453
README.md	Added Wultra Logging Support section

[Copilot]

Pull request overview

Adds a new logging-support module to java-core intended for dev/test Logback configurations, providing a custom ClassicConverter to render StructuredArguments.kv() key-value pairs in plain-text log patterns (addressing #453).

Changes:

• Added new Maven module logging-support and included it in the parent build.
• Implemented StructuredArgumentsConverter and accompanying JUnit tests.
• Published the new module via the project BOM.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
pom.xml	Registers logging-support module and introduces logstash.version property.
bom/pom.xml	Adds logging-support to dependency management so consumers can import it consistently.
logging-support/pom.xml	Defines the new module and its Logback / logstash encoder dependencies plus test setup.
logging-support/src/main/java/com/wultra/core/logging/logback/StructuredArgumentsConverter.java	Adds the Logback pattern converter that appends structured key/value pairs.
logging-support/src/test/java/com/wultra/core/logging/logback/StructuredArgumentsConverterTest.java	Adds unit tests covering structured, empty, null, and mixed argument cases.

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[banterCZ]

May we please include that in the changelog and README?

[vita-kotacka]

Added Changelog entry for #453 and a new Wultra Logging Support section to the README documenting StructuredArgumentsConverter usage.

[banterCZ]

Thanks for reflecting the comments.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.