2. Architecture Constraints

Technical Constraints

ID Constraint Consequence

ID	Constraint	Consequence
TC1	Java 21	`maven.compiler.source/target` is 21. The code uses records, `var`, switch patterns and `List.getFirst()`, so consumers cannot run on an older JDK.
TC2	Maven 3.9.2 or later	Enforced by `maven-enforcer-plugin`. The floor comes from `central-publishing-maven-plugin`, not from our own code.
TC3	Confluence Cloud REST API v2	The client is generated from Atlassian’s OpenAPI v2 specification. Confluence Server and Data Center are not supported, because their API differs.
TC4	Attachment upload only exists in API v1	REST v2 has no endpoint that creates an attachment. The one v1 call `PUT /rest/api/content/{id}/child/attachment` has to remain — see 9. Architecture Decisions and 11. Risks and Technical Debt.
TC5	Confluence Storage Format is XHTML	Content must be well-formed XML, not lenient HTML. Determines how documents are parsed and serialised, see 8. Cross-cutting Concepts.
TC6	Antora 3.1 output structure	The parser reads the generated `index.html` and its navigation panel. The HTML structure of the Antora default UI is an implicit contract.

TC1

Java 21

maven.compiler.source/target is 21. The code uses records, var, switch patterns and List.getFirst(), so consumers cannot run on an older JDK.

TC2

Maven 3.9.2 or later

Enforced by maven-enforcer-plugin. The floor comes from central-publishing-maven-plugin, not from our own code.

TC3

Confluence Cloud REST API v2

The client is generated from Atlassian’s OpenAPI v2 specification. Confluence Server and Data Center are not supported, because their API differs.

TC4

Attachment upload only exists in API v1

REST v2 has no endpoint that creates an attachment. The one v1 call PUT /rest/api/content/{id}/child/attachment has to remain — see 9. Architecture Decisions and 11. Risks and Technical Debt.

TC5

Confluence Storage Format is XHTML

Content must be well-formed XML, not lenient HTML. Determines how documents are parsed and serialised, see 8. Cross-cutting Concepts.

TC6

Antora 3.1 output structure

The parser reads the generated index.html and its navigation panel. The HTML structure of the Antora default UI is an implicit contract.

Organisational and Legal Constraints

ID Constraint Consequence

ID	Constraint	Consequence
OC1	Apache License 2.0	Every dependency must carry a compatible licence. Source files keep the licence header.
OC2	Distribution via Maven Central	Requires GPG-signed artifacts, sources and javadoc JARs, and complete POM metadata. Published through `central-publishing-maven-plugin`; releases are triggered by a GitHub release, snapshots on every push to `main`.
OC3	Single maintainer	The architecture favours few moving parts over completeness. Anything that cannot be maintained by one person on a spare evening does not belong in the system.
OC4	Credentials are never part of the repository	Authentication data comes from `settings.xml` or the plugin configuration of the consuming project, never from this project’s own configuration.

OC1

Apache License 2.0

Every dependency must carry a compatible licence. Source files keep the licence header.

OC2

Distribution via Maven Central

Requires GPG-signed artifacts, sources and javadoc JARs, and complete POM metadata. Published through central-publishing-maven-plugin; releases are triggered by a GitHub release, snapshots on every push to main.

OC3

Single maintainer

The architecture favours few moving parts over completeness. Anything that cannot be maintained by one person on a spare evening does not belong in the system.

OC4

Credentials are never part of the repository

Authentication data comes from settings.xml or the plugin configuration of the consuming project, never from this project’s own configuration.

Conventions

Code style: tab indentation, final on locals and parameters wherever possible, Javadoc on every public type and method.
Logging: SLF4J with parameterised messages. info for what happened to the space, debug for detail, warn for skipped-but-continued, error for a failed unit of work.
Dependencies: managed centrally in the parent POM via dependencyManagement; modules declare artifacts without versions.
Documentation: arc42 in AsciiDoc, published with this project’s own Maven plugin.

OC4 and quality goal 4 in 1. Introduction and Goals together forbid a convenience that would otherwise be obvious — exposing username and password as CLI properties. They are configuration-only parameters precisely so that they cannot land in a CI log.