BarBridge — Boss Bar Plugin & API for Spigot 1.8.x

Commands and usage

Drop BarBridge-1.0.0.jar into your server's plugins/ folder.

ProtocolLib is OPTIONAL on the server but HIGHLY recommended to cover all edge cases.

Commands:

Permission required: barbridge.admin

/bar set <player|*>

/bar timed <player|*>

/bar msg <player|*>

/bar health <player|*> [message]

/bar remove <player|*>

Subcommand aliases: msg = message, update remove = clear

All messages support &-style color codes.

USING AS AN API

1. Add BarBridge-1.0.0.jar to your plugin's libs/ folder (using the same nested-repo pattern, OR install to your local m2 repo)

2. Add depend in your plugin.yml:

   depend: [BarBridge]

3. Call the API:

   import com.mireacul.barbridge.BarBridge;

   BarBridge api = BarBridge.getInstance();

   api.setBar(player, "&eWelcome!");

   api.setBar(player, "&eThis Bar is at Half Health", 50f);

   api.setTimedBar(player, 30, "&aFight starts in 30s");

   api.updateMessage(player, "&bResolved");

   api.updateHealth(player, 75f);

   api.updateAll(player, "&cBoss", 100f);

   api.removeBar(player);

   if (api.hasBar(player)) {

   String msg = api.getMessage(player);
   
   float pct  = api.getHealth(player);
   

   }

API REFERENCE

void setBar(Player, String) - persistent at 100%

void setBar(Player, String, float percent) - persistent at given %

void setTimedBar(Player, int seconds, String) - drains 100->0, auto-removes

void updateMessage(Player, String) - text only

void updateHealth(Player, float percent) - fill only

void updateAll(Player, String, float percent) - both

void removeBar(Player) - hide

boolean hasBar(Player) - active?

String getMessage(Player) - current text or null

float getHealth(Player) - current % or -1

How BarBridge Works

Minecraft 1.8 doesn't have a real boss bar API. The only way to show a boss bar to a player is to spawn a wither or ender dragon near them. The boss bar in their HUD is automatically driven by that entity's custom name and health.

BarBridge fakes a wither without actually spawning one on the server.

For each player with a bar, BarBridge sends them a packet that says "hey, there's a wither at this location." The wither only exists on that one client. The server has no entity, no AI, no collision.

Each player gets their own personal wither. That way every player can see a different message and a different timer at the same time.

Why it doesn't make smoke or noise

Withers normally do two annoying things:

1. They emit black smoke particles you can see from a distance.
2. They make ambient growling sounds.

The fix for both is the same: spawn the wither 256 blocks above the player. That's higher than the 1.8 build height, so the wither is in dead sky where no player can ever look. Smoke gets emitted but nobody is close enough to render it. Sounds attenuate to silence at that range.

Following the player

The wither has to stay near the player or the boss bar disappears from their HUD. Every tick, BarBridge checks if the player moved:

• If they crossed a chunk boundary: destroy and respawn the wither.
• If they just walked a bit: send a teleport packet.
• If they didn't move: do nothing.

This keeps the bar visible without spamming packets.

ProtocolLib (optional)

ProtocolLib is used for two edge cases:

1. Cancel a player's "attack entity" packet if they somehow target the fake wither (basically impossible at Y+256, but free safety).
2. Mute any wither sounds that do reach the player.

Both are nice-to-haves. The +256 height already handles 99% of the problem on its own, so ProtocolLib is a soft dependency the plugin runs without it.

BUILDING

ProtocolLib.jar is already pre-positioned at: libs/com/comphenix/protocol/ProtocolLib/local/ProtocolLib-local.jar

Build: mvn clean package

Output: target/BarBridge-1.0.0.jar

THREADING

The internal bar map uses ConcurrentHashMap, so concurrent reads and writes from multiple threads will not corrupt state. In practice most callers invoke the API from the main server thread (commands, Bukkit events, sync BukkitRunnables), and that remains the recommended pattern since NMS packet sending is most commonly done there.