Fix unnecessary regeneration of message/field classes on every build

[Copilot]

Fix unnecessary regeneration of message/field classes on every build

Plan

• Explore repository structure and understand the build process
• Confirm the problem: code generation runs on every build even when FIX spec XML files haven't changed
• Analyze the quickfixj-messages-all POM to understand the code generation plugin configuration
• Add skip parameter to quickfixj-codegenerator plugin
• Implement up-to-date detection using maven-antrun-plugin with Ant uptodate task
• Configure code generation to skip when inputs are unchanged
• Add comments/documentation explaining the up-to-date detection mechanism (DONE in POM comments)
• Address PR review comments (move version property to parent POM)
• Fix duplicate maven-antrun-plugin declaration warning
• Test that generation runs on clean build
• Test that generation is skipped on second build without changes
• Test that generation runs again when XML files are modified
• Run code review
• Run security scan

Original prompt

Goal: Fix #1022 so that generated message and field classes are not regenerated on every build when the FIX spec XML files have not changed.

Background:

• In this repo there are FIX spec XML files named like FIX*.xml located under ./quickfixj-messages/ and its subdirectories.
• During the Maven build, fields and message classes are generated from these specs.
• Currently, even without running mvn clean, these generated sources are rebuilt every time.

Requirements:

1. Update the Maven build so that generation of message and field classes only runs when the corresponding FIX spec XML input(s) have changed.
2. Use mojohaus build-helper:uptodate-property (or an equivalent Maven approach) to detect whether the spec XML inputs are up-to-date.
3. Ensure the generator output is still produced when:
   • Building from a clean checkout
   • Any relevant FIX*.xml spec file is added/removed/modified
4. Ensure incremental builds skip the generation step when inputs are unchanged.
5. The solution should work across all spec locations under quickfixj-messages/ (and subdirectories) that are used by the generator.
6. Add/adjust documentation or comments in the POM(s) explaining the up-to-date detection and how it works.
7. Add or update build verification (tests or a lightweight build check) if appropriate to prevent regressions (e.g., a CI step or Maven profile that demonstrates generation is skipped on second run).

Implementation notes:

• Prefer a robust approach: compute an up-to-date property by comparing timestamps or checksums of inputs and outputs, then conditionally execute the generation plugin using Maven plugin configuration or profiles.
• Keep the build portable (no OS-specific scripts) and compatible with typical Maven invocations.

Acceptance criteria:

• Running mvn -pl quickfixj-messages -am test (or the repo’s standard build) twice without changing any FIX*.xml results in the second run skipping message/field generation.
• Modifying any FIX*.xml under the relevant paths causes generation to run again and update generated sources.

Please open a PR with the changes.

This pull request was created from Copilot chat.

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[chrjohn]

@copilot please move the version property into the properties section of the main pom.xml

[Copilot]

Done in commit 9f8f38b. Added maven-antrun-plugin-version property to parent pom.xml and updated all usages in quickfixj-messages-all and quickfixj-messages-fixt11 POMs.

[chrjohn]

@copilot the build generates a warning:

Some problems were encountered while building the effective model for org.quickfixj:quickfixj-messages-all:jar:3.0.0-SNAPSHOT
'build.plugins.plugin.(groupId:artifactId)' must be unique but found duplicate declaration of plugin org.apache.maven.plugins:maven-antrun-plugin @ line 452, column 12

Please correct that.

[Copilot]

Fixed in commit 78b7121. Consolidated the two maven-antrun-plugin declarations into a single plugin with three executions, eliminating the duplicate declaration warning.