@torba/java

OpenJDK runtime support for torba — auto-installs an Eclipse Temurin JDK and exposes ${java_home} and ${java_bin} as standardized vars so loader templates can reference a portable Java binary.

Install

npm install @torba/java

Usage

import { resolveJava } from '@torba/java';
import { resolveLwjgl3ify } from '@torba/lwjgl3ify';

const lw = await resolveLwjgl3ify({ version: '3.0.16' });
const jav = await resolveJava({ version: '21' });

return {
  manifest: {
    artifacts: [lw.artifacts, jav.artifacts],
    vars: { ...lw.vars, ...jav.vars },
    launch: lw.launch, // launch.command is `${java_bin}` already
  },
};

Version input

• Major — '21', '17' — resolves to the latest GA release for that major.
• Full version — '21.0.11+10' — exact Adoptium release name (jdk- prefix and -LTS suffix are tolerated).

Options

resolveJava({
  version: string,
  vendor?: 'openjdk',         // only OpenJDK (Temurin) is supported today
  platforms?: JavaPlatform[], // override the default OS/arch matrix
  apiBase?: string,           // override the Adoptium API base URL
});

How it works

1. Resolves the requested version against https://api.adoptium.net/v3/. Major versions hit /feature_releases/<n>/ga (latest GA); full versions hit /release_name/eclipse/jdk-<v> (exact).
2. Queries each platform (linux/osx/windows × x86_64+aarch64) in parallel; soft-skips combinations that don't ship a binary.
3. Emits one Artifact per platform pointing at the GitHub-hosted release asset, with sha256 from the API and OS+arch rules so only the matching binary downloads at install time.
4. Each artifact has an extract: dump rule pointing at ${root}/runtimes/jdk-<major>/, so the JDK lands at ${root}/runtimes/jdk-<major>/jdk-<full>/.
5. Sets java_home (per OS — macOS gets the /Contents/Home suffix) and java_bin (${java_home}/bin/java on POSIX, ${java_home}/bin/java.exe on Windows).

@torba/installer extracts both .zip (Windows) and .tar.gz / .tgz (Linux/macOS) archives, preserving the executable bit on tar entries so bin/java stays runnable without a chmod step.

Standard ${java_home} and ${java_bin} vars

Every torba template returned by @torba/minecraft (and by any loader built on it) now sets launch.command = '${java_bin}', with java_bin defaulting to the literal 'java' (PATH lookup). When you spread @torba/java's vars over the loader's, the var resolves to the auto-installed JDK instead — without any change to the launch command.

Notes

• Vendor: only openjdk (Eclipse Temurin) is supported. Adding Liberica, Zulu, GraalVM is a matter of plugging in another resolver.
• macOS app bundles: macOS Temurin tarballs ship as .app bundles with Contents/MacOS/_CodeSignature/.... ${java_home} includes the /Contents/Home suffix automatically.
• Disk usage: each JDK is ~200 MB compressed, ~500 MB extracted. The archive is downloaded into ${root}/runtimes/ as a sibling of the jdk-<major>/ extract target — delete the leftover .tar.gz/.zip archive there to reclaim space.