Automatically queue packets to send when a player connects, and change the API regarding this. Please don't use the Server methods anymore, instead use ServerInfo.

CC: @TheDgtl

api/src/main/java/net/md_5/bungee/api/ProxyServer.java

@@ -2,6 +2,7 @@ package net.md_5.bungee.api;
 
 import net.md_5.bungee.api.plugin.PluginManager;
 import com.google.common.base.Preconditions;
+import java.net.InetSocketAddress;
 import java.util.Collection;
 import java.util.Map;
 import java.util.logging.Logger;
@@ -75,7 +76,11 @@ public abstract class ProxyServer
      *
      * @param name the name to lookup
      * @return the associated server
+     * @deprecated in most cases the {@link #getServerInfo(java.lang.String)}
+     * method should be used, as it will return a server even when no players
+     * are online.
      */
+    @Deprecated
     public abstract Server getServer(String name);
 
     /**
@@ -196,4 +201,14 @@ public abstract class ProxyServer
      * @return the Minecraft protocol version
      */
     public abstract byte getProtocolVersion();
+
+    /**
+     * Factory method to construct an implementation specific server info
+     * instance.
+     *
+     * @param name name of the server
+     * @param address connectable Minecraft address + port of the server
+     * @return the constructed instance
+     */
+    public abstract ServerInfo constructServerInfo(String name, InetSocketAddress address);
 }

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

@@ -7,6 +7,8 @@ import java.util.Collections;
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.Synchronized;
+import net.md_5.bungee.api.Callback;
+import net.md_5.bungee.api.ServerPing;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 
 /**
@@ -14,7 +16,7 @@ import net.md_5.bungee.api.connection.ProxiedPlayer;
  */
 @Data
 @AllArgsConstructor
-public class ServerInfo
+public abstract class ServerInfo
 {
 
     /**
@@ -62,4 +64,19 @@ public class ServerInfo
     {
         return Collections.unmodifiableCollection(players);
     }
+
+    /**
+     * Send data by any available means to this server.
+     *
+     * @param channel the channel to send this data via
+     * @param data the data to send
+     */
+    public abstract void sendData(String channel, byte[] data);
+
+    /**
+     * Asynchronously gets the current player count on this server.
+     *
+     * @param callback the callback to call when the count has been retrieved.
+     */
+    public abstract void ping(Callback<ServerPing> callback);
 }

api/src/main/java/net/md_5/bungee/api/connection/Server.java

@@ -1,8 +1,8 @@
 package net.md_5.bungee.api.connection;
 
 import net.md_5.bungee.api.Callback;
-import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.api.ServerPing;
+import net.md_5.bungee.api.config.ServerInfo;
 
 /**
  * Represents a destination which this proxy might connect to.
@@ -29,6 +29,9 @@ public interface Server extends Connection
      * Asynchronously gets the current player count on this server.
      *
      * @param callback the callback to call when the count has been retrieved.
+     * @deprecated use the corresponding method in {@link ServerInfo} for
+     * clarity
      */
+    @Deprecated
     public abstract void ping(Callback<ServerPing> callback);
 }

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

@@ -5,6 +5,7 @@ import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.util.Collection;
 import java.util.Collections;
@@ -339,4 +340,10 @@ public class BungeeCord extends ProxyServer
     {
         return GAME_VERSION;
     }
+
+    @Override
+    public ServerInfo constructServerInfo(String name, InetSocketAddress address)
+    {
+        return new BungeeServerInfo(name, address);
+    }
 }

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

@@ -0,0 +1,76 @@
+package net.md_5.bungee;
+
+import java.io.DataOutputStream;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.util.Queue;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import lombok.Getter;
+import net.md_5.bungee.api.Callback;
+import net.md_5.bungee.api.ProxyServer;
+import net.md_5.bungee.api.ServerPing;
+import net.md_5.bungee.api.config.ServerInfo;
+import net.md_5.bungee.api.connection.Server;
+import net.md_5.bungee.packet.DefinedPacket;
+import net.md_5.bungee.packet.PacketFAPluginMessage;
+import net.md_5.bungee.packet.PacketFFKick;
+import net.md_5.bungee.packet.PacketInputStream;
+
+public class BungeeServerInfo extends ServerInfo
+{
+
+    @Getter
+    private final Queue<DefinedPacket> packetQueue = new ConcurrentLinkedQueue<>();
+
+    public BungeeServerInfo(String name, InetSocketAddress address)
+    {
+        super(name, address);
+    }
+
+    @Override
+    public void sendData(String channel, byte[] data)
+    {
+        Server server = ProxyServer.getInstance().getServer(getName());
+        if (server != null)
+        {
+            server.sendData(channel, data);
+        } else
+        {
+            packetQueue.add(new PacketFAPluginMessage(channel, data));
+        }
+    }
+
+    @Override
+    public void ping(final Callback<ServerPing> callback)
+    {
+        new Thread()
+        {
+            @Override
+            public void run()
+            {
+                try
+                {
+                    Socket socket = new Socket();
+                    socket.connect(getAddress());
+                    try (DataOutputStream out = new DataOutputStream(socket.getOutputStream()))
+                    {
+                        out.write(0xFE);
+                        out.write(0x01);
+                    }
+                    try (PacketInputStream in = new PacketInputStream(socket.getInputStream()))
+                    {
+                        PacketFFKick response = new PacketFFKick(in.readPacket());
+
+                        String[] split = response.message.split("\00");
+
+                        ServerPing ping = new ServerPing(Byte.parseByte(split[1]), split[2], split[3], Integer.parseInt(split[4]), Integer.parseInt(split[5]));
+                        callback.done(ping, null);
+                    }
+                } catch (Throwable t)
+                {
+                    callback.done(null, t);
+                }
+            }
+        }.start();
+    }
+}

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

@@ -95,6 +95,12 @@ public class ServerConnection extends GenericConnection implements Server
 
             out.write(BungeeCord.getInstance().registerChannels().getPacket());
 
+            Queue<DefinedPacket> packetQueue = ((BungeeServerInfo) info).getPacketQueue();
+            while (!packetQueue.isEmpty())
+            {
+                out.write(packetQueue.poll().getPacket());
+            }
+
             return server;
         } catch (KickException ex)
         {
@@ -122,35 +128,7 @@ public class ServerConnection extends GenericConnection implements Server
     @Override
     public void ping(final Callback<ServerPing> callback)
     {
-        new Thread()
+        getInfo().ping(callback);
-        {
-            @Override
-            public void run()
-            {
-                try
-                {
-                    Socket socket = new Socket();
-                    socket.connect(getAddress());
-                    try (DataOutputStream out = new DataOutputStream(socket.getOutputStream()))
-                    {
-                        out.write(0xFE);
-                        out.write(0x01);
-                    }
-                    try (PacketInputStream in = new PacketInputStream(socket.getInputStream()))
-                    {
-                        PacketFFKick response = new PacketFFKick(in.readPacket());
-
-                        String[] split = response.message.split("\00");
-
-                        ServerPing ping = new ServerPing(Byte.parseByte(split[1]), split[2], split[3], Integer.parseInt(split[4]), Integer.parseInt(split[5]));
-                        callback.done(ping, null);
-                    }
-                } catch (Throwable t)
-                {
-                    callback.done(null, t);
-                }
-            }
-        }.start();
     }
 
     @Override

proxy/src/main/java/net/md_5/bungee/config/YamlConfig.java

@@ -151,7 +151,7 @@ public class YamlConfig implements ConfigurationAdapter
             String name = entry.getKey();
             String addr = get("address", "localhost:25565", val);
             InetSocketAddress address = Util.getAddr(addr);
-            ServerInfo info = new ServerInfo(name, address);
+            ServerInfo info = ProxyServer.getInstance().constructServerInfo(name, address);
             ret.put(name, info);
         }