ddd4j-boot Extensions

Overview

Covers Akka, Excel, QLExpress, QRCode, Monitor, and other current extensions uniformly, not split per artifact. Before use, confirm the maintenance line through ddd4j-boot-version-selection.

When to Use

• Deciding whether a need (Akka actors, Excel export, QLExpress rules, QR code generation, monitoring helper) maps to an existing ddd4j-boot-extensions submodule.
• Wiring an optional extension through its auto-configuration: classpath guards, enabled switches, and @ConditionalOnMissingBean defaults.
• Verifying that disabling an extension degrades gracefully without breaking core assembly.
• Checking that an extension is guarded on the classpath so absence of its third-party library skips assembly instead of failing startup.
• Adding usage evidence for an extension: enabled, disabled, and classpath-missing context tests.
• Marking requested-but-absent extensions as NOT IMPLEMENTED instead of inventing modules or APIs.

When NOT to Use

Do not use this skill when: