Java Management

Fabricator can manage Java runtimes per server. This avoids forcing every Minecraft version to use the same system Java.

Runtime resolution order

When Fabricator starts a server, it resolves the Java executable in this order:

1. javaPath stored on the server record, if present.
2. A managed Java runtime under JAVA_ROOT that satisfies the server's Minecraft version requirement.
3. java from PATH as a fallback, allowing the normal missing-Java flow to trigger.

Compatibility checks

Fabricator computes the required Java major version from the Minecraft version. If the detected runtime is too old, start/install can be blocked and the UI can show an install recommendation.

Installing Java from the UI

The Java API exposes:

• Current runtime status.
• Recommended download URL for the host OS/architecture and required Java version.
• Install progress for background Java installs.
• Cancellation for install tasks.

Managed runtimes default to /var/lib/fabricator/java in production.

Development bypass

FABRICATOR_SKIP_JAVA_CHECK=1 disables enforcement for development/testing only. Do not enable it in production.