Add ServerInfo method to send plugin message only if server is online

api/src/main/java/net/md_5/bungee/api/config/ServerInfo.java

@@ -57,9 +57,24 @@ public interface ServerInfo
      *
      * @param channel the channel to send this data via
      * @param data the data to send
+     * @deprecated use #sendData(String, byte[], boolean). Deprecated to highlight queuing behaviour of this method.
+     * @see #sendData(String, byte[], boolean)
      */
+    @Deprecated
     void sendData(String channel, byte[] data);
 
+    /**
+     * Send data by any available means to this server.
+     *
+     * @param channel the channel to send this data via
+     * @param data the data to send
+     * @param queueIfEmpty if set to <code>true</code> and this server is empty, the data will be queued until a player
+     *                     joins that server.
+     * @return <code>true</code> if the message was sent immediately, <code>false</code> otherwise (if queueIfEmpty is
+     * true, it has been queued, if it is false it has been discarded).
+     */
+    boolean sendData(String channel, byte[] data, boolean queueIfEmpty);
+
     /**
      * Asynchronously gets the current player count on this server.
      *

proxy/src/main/java/net/md_5/bungee/BungeeServerInfo.java

@@ -88,9 +88,15 @@ public class BungeeServerInfo implements ServerInfo
         return address.hashCode();
     }
 
-    // TODO: Don't like this method
     @Override
     public void sendData(String channel, byte[] data)
+    {
+        sendData( channel, data, true );
+    }
+
+    // TODO: Don't like this method
+    @Override
+    public boolean sendData(String channel, byte[] data, boolean queue)
     {
         Preconditions.checkNotNull( channel, "channel" );
         Preconditions.checkNotNull( data, "data" );
@@ -101,10 +107,12 @@ public class BungeeServerInfo implements ServerInfo
             if ( server != null )
             {
                 server.sendData( channel, data );
-            } else
+                return true;
+            } else if ( queue )
             {
                 packetQueue.add( new PluginMessage( channel, data ) );
             }
+            return false;
         }
     }