Double Doors Server

A Bukkit/Spigot plugin that opens mirrored double doors together, with low-latency syncing and optional compatibility handling for common server stacks.

Features

• Same-tick partner door sync (no scheduled 1-tick delay)
• Strict mirrored pair matching for doors:
  • same door type
  • same facing direction
  • opposite hinge
  • side-by-side only
• Optional recursive opening support for non-door openables (fence gates/trapdoors)
• Per-player toggle: /doubledoors toggle
• LuckPerms-friendly permission nodes
• GriefPrevention compatibility check for linked-door claim access
• Duplicate interaction debounce (helps packet duplication patterns seen with some Bedrock/Geyser flows)
• Translation support via JSON language files (built-in + custom)

Compatibility

• Supports Minecraft Java Edition 1.21.x and 26.1.x.

Geyser / Floodgate

• Plugin declares soft-depends on Geyser-Spigot and floodgate.
• A short duplicate-interaction debounce window is used to avoid rapid duplicate toggles on the same block.

LuckPerms

• Works through standard Bukkit permissions, so LuckPerms applies automatically.
• Use doubledoors.use to allow/deny linked opening behavior.

GriefPrevention

• Plugin declares a soft-depend on GriefPrevention.
• When present, linked-door interaction is checked against claim build permission before toggling the partner door.

Folia

• Folia is supported with region-aware scheduling for delayed block updates and shared-state access.

Proxy Setup (Multi-Server)

DoubleDoors includes an optional Velocity proxy plugin for Geyser/Floodgate environments with multiple backend servers.

Proxy Features

• Shared SQL heartbeat/presence tracking across multiple proxies
• Automatic detection of Geyser/Floodgate clients
• Support for SQLite and MySQL databases
• Connection pooling via HikariCP for efficient SQL resource usage

Proxy Installation

1. Download the proxy JAR from the releases page (doubledoors-proxy-<version>.jar)
2. Place it in your Velocity plugins/ directory
3. Restart the proxy
4. A plugins/DoubleDoors/proxy-config.properties file will be generated

Proxy Configuration

Edit plugins/DoubleDoors/proxy-config.properties:

# Enable SQL heartbeat reporting (requires Geyser/Floodgate on this proxy)
sql.enabled=false

# JDBC URL for the shared database
# SQLite example: jdbc:sqlite:plugins/DoubleDoors/doubledoors.db
# MySQL example: jdbc:mysql://localhost:3306/doubledoors
sql.jdbcUrl=jdbc:sqlite:plugins/DoubleDoors/doubledoors.db

# SQL authentication (leave blank for SQLite)
sql.username=
sql.password=

# Unique proxy identifier (for multi-proxy setups)
sql.proxyId=velocity-main

# Heartbeat interval in seconds (minimum 5 seconds)
sql.heartbeatSeconds=30

Multi-Proxy Example

For a setup with multiple Velocity proxies reporting to a shared MySQL database:

Proxy 1:

sql.enabled=true
sql.jdbcUrl=jdbc:mysql://db.example.com:3306/doubledoors
sql.username=dd_user
sql.password=dd_pass
sql.proxyId=velocity-us
sql.heartbeatSeconds=30

Proxy 2:

sql.enabled=true
sql.jdbcUrl=jdbc:mysql://db.example.com:3306/doubledoors
sql.username=dd_user
sql.password=dd_pass
sql.proxyId=velocity-eu
sql.heartbeatSeconds=30

Commands

• /doubledoors reload - reload config
• /doubledoors toggle - toggle behavior for yourself
• /doubledoors knock-volume <0-1> - set personal knock sound volume
• /doubledoors server-toggle - toggle behavior server-wide

Permissions

• doubledoors.use (default: true)
• doubledoors.knock.volume (default: true)
• doubledoors.toggle (default: true)
• doubledoors.reload (default: op)
• doubledoors.server-toggle (default: op)

Config

src/main/resources/config.yml

• enableRecursiveOpening (default: true)
• recursiveOpeningMaxBlocksDistance (default: 10)
• enableDoors (default: true)
• enableFenceGates (default: true)
• enableTrapdoors (default: true)
• enableVillagerLinkedDoors (default: true)
• serverWideEnabled (default: true)
• language (default: en_US)

Update Checker

• Built-in update checks are controlled by updateChecker.enabled in config.yml.
• If a standalone PluginUpdater plugin is installed, DoubleDoors automatically disables its own built-in checks to avoid duplicate notifications.
• Startup logs explicitly state whether update checks are:
  • enabled via DoubleDoors built-in updater,
  • disabled by config,
  • or delegated to standalone PluginUpdater.
• When delegating to standalone PluginUpdater, configure that plugin to include DoubleDoors update notifications.

Troubleshooting:

• If you do not receive update notifications, first check startup logs to see which updater path is active.
• If built-in checks are active, verify updateChecker.enabled and related notify/schedule settings.
• If checks are delegated, verify standalone PluginUpdater configuration and permissions for who should receive update notices.

Language files:

• Built-in fallback file: src/main/resources/lang/en_US.json
• Runtime custom language folder: plugins/DoubleDoors/lang/
• Set active language with language: <code> in config.yml (example: language: de_DE)
• Custom files are JSON objects of key/value strings and override built-in messages when present.

Build

Requirements:

• Java 25+
• Maven

Build command:

mvn -DskipTests package

Output jar is generated under target/.

License

Licensed under the GNU General Public License v3.0. See LICENSE.