Docker images for Java-based applications (Minecraft servers, Spring applications, etc.). Uses Eclipse Temurin JDK with Debian base.

This project maintains the following Java versions:

• LTS (Long-Term Support): Java 11, 17, 21, 26 - Actively built and maintained
• Current Releases: Java 22, 25 - Built on each release
• Legacy: Java 8 - Archives only, not actively built
• EOL (End-of-Life): Java 16, 19 - Not built (IBM Semeru missing multiarch support, upstream EOL)

To use EOL versions, build locally from the Dockerfile:

docker build -t java:16 java/16/

• [version]/Dockerfile - Java JDK with development tools for specified version
• entrypoint.sh - Container entrypoint with STARTUP variable support
• README.md - This file

docker run -it \
  -e STARTUP="java -jar app.jar" \
  -p 8080:8080/tcp \
  ghcr.io/nodebytehosting/java:java_25

version: '3.8'

services:
  java-app:
    image: ghcr.io/nodebytehosting/java:java_25
    ports:
      - "8080:8080/tcp"
    environment:
      STARTUP: "java -Xmx1024m -jar app.jar"
      TZ: UTC
    volumes:
      - ./app:/home/container
    restart: unless-stopped

docker build -t java:25 java/25/
docker run -it -e STARTUP="java -jar app.jar" java:25

The entrypoint supports Pterodactyl-style variable substitution:

# Input
STARTUP="java -Xmx{{MEMORY}}m -Xms{{MEMORY}}m -jar server.jar"

# Output
STARTUP="java -Xmx2048m -Xms2048m -jar server.jar"

• lsof - List open files
• curl - HTTP/HTTPS downloads
• wget - Alternative downloader
• git - Clone repositories
• tar - Archive extraction
• sqlite3 - Database utility
• openssl - SSL/TLS utilities
• ca-certificates - Certificate authorities
• fontconfig, libfreetype6 - Font rendering
• libstdc++6 - C++ runtime

docker run -it \
  -e STARTUP="java -Xmx2048m -Xms1024m -jar server.jar nogui" \
  -p 25565:25565/tcp \
  -v ./server:/home/container \
  ghcr.io/nodebytehosting/java:java_25

docker run -it \
  -e STARTUP="java -jar app.jar --server.port=8080" \
  -p 8080:8080/tcp \
  -v ./app:/home/container \
  ghcr.io/nodebytehosting/java:java_25

docker run -it \
  -e STARTUP="java -Xmx4096m -Xms2048m -XX:+UseG1GC -XX:MaxGCPauseMillis=200 -jar app.jar" \
  ghcr.io/nodebytehosting/java:java_25

• Java 25 - Latest version (September 2024)
• Base: Eclipse Temurin JDK (open-source OpenJDK build)
• OS: Debian Bookworm slim
• Platform: linux/amd64, linux/arm64 (multiarch)

To add support for other Java versions, create additional directories:

mkdir -p java/21 java/17 java/11

Update each Dockerfile to use the desired Eclipse Temurin base:

FROM eclipse-temurin:21-jdk
# ... rest of Dockerfile

Then add versions to the GitHub Actions workflow matrix:

matrix:
  tag:
    - 11
    - 17
    - 21
    - 25

1. Set JVM memory limits - Use -Xmx and -Xms for consistent performance
2. Use G1GC for large heaps - -XX:+UseG1GC for heaps > 4GB
3. Enable aggressive optimization - -XX:+AggressiveOptimization for compute-intensive apps
4. Monitor with tools - jps, jstat, jconsole available in container
5. Use volume mounts - Mount application directory to persist data and logs

• Check STARTUP variable is set correctly
• Run java -version to verify Java is available
• Check application logs for Java errors

• Increase -Xmx value (max heap size)
• Check container memory limits: docker stats
• Monitor with jstat -gc <pid> 1000

• Verify JAR file is in /home/container
• Check classpath with java -cp if using multiple JARs
• Ensure all dependencies are included

MIT License - See LICENSE file for details

• Issues: https://github.com/NodeByteHosting/game-recipes/issues
• Discord: https://discord.gg/Bg3Sf5fqa4
• Java Docs: https://docs.oracle.com/en/java/
• Eclipse Temurin: https://adoptium.net/