Java

Curated name java. Installs a JDK via the upstream devcontainers/features/java feature. Monoceros turns on Maven and Gradle by default (the upstream feature ships only the JDK), so a plain languages: [java] is build-ready out of the box.

Add it

monoceros init acme --with-languages=java
monoceros add-language acme java:21

Either writes the object form into the yml, with the version and the Maven/Gradle toggles inline and editable:

languages:
  - java:
      version: latest
      installMaven: true
      installGradle: true

Remove it

monoceros remove-language acme java

Or delete the entry from acme.yml by hand and re-run monoceros apply acme - the yml is the source of truth.

Pinning a version

Pin a JDK major with the :version suffix; it lands in the version key above.

monoceros add-language acme java:21

Supported JDK majors: 21, 17, 11, 8 (also latest).

Options

version, installMaven and installGradle are surfaced in the yml - edit them in place (e.g. set installMaven: false), then monoceros apply. Other options are set by adding the feature directly (see Other feature options):

Option	Default	Where to set
`version`	`latest`	yml (`:version` suffix or the `version` key)
`installMaven`	`true` (Monoceros default; upstream `false`)	yml
`installGradle`	`true` (Monoceros default; upstream `false`)	yml
`jdkDistro`	`ms`	`add-feature` (`ms`, `open`, `oracle`, `tem`, `amzn`)
`mavenVersion` / `gradleVersion`	`latest`	`add-feature`

Full option list: upstream feature.