Implement server ping method.

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

@@ -25,9 +25,9 @@ public class ServerPing
     /**
      * Current amount of players on the server.
      */
-    private final String currentPlayers;
+    private final int currentPlayers;
     /**
      * Max amount of players the server will allow.
      */
-    private final String maxPlayers;
+    private final int maxPlayers;
 }

api/src/main/java/net/md_5/bungee/api/event/ProxyPingEvent.java

@@ -1,30 +1,27 @@
 package net.md_5.bungee.api.event;
 
-import java.net.InetSocketAddress;
+import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
 import net.md_5.bungee.api.ServerPing;
-import net.md_5.bungee.api.config.ListenerInfo;
+import net.md_5.bungee.api.connection.PendingConnection;
 import net.md_5.bungee.api.plugin.Event;
 
 /**
  * Called when the proxy is pinged with packet 0xFE from the server list.
  */
 @Data
+@AllArgsConstructor
 @ToString(callSuper = true)
 @EqualsAndHashCode(callSuper = true)
 public class ProxyPingEvent extends Event
 {
 
     /**
-     * The address of the user pinging.
+     * The connection asking for a ping response.
      */
-    private final InetSocketAddress remoteAddress;
+    private final PendingConnection connection;
-    /**
-     * The data corresponding to the server which received this ping.
-     */
-    private final ListenerInfo server;
     /**
      * The data to respond with.
      */

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

@@ -47,7 +47,7 @@ public class BungeeCord extends ProxyServer
     /**
      * Server protocol version.
      */
-    public static final int PROTOCOL_VERSION = 51;
+    public static final byte PROTOCOL_VERSION = 51;
     /**
      * Server game version.
      */

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

@@ -11,11 +11,13 @@ import javax.crypto.SecretKey;
 import lombok.Getter;
 import net.md_5.bungee.api.ChatColor;
 import net.md_5.bungee.api.ProxyServer;
+import net.md_5.bungee.api.ServerPing;
 import net.md_5.bungee.api.config.ListenerInfo;
 import net.md_5.bungee.api.config.ServerInfo;
 import net.md_5.bungee.api.connection.PendingConnection;
 import net.md_5.bungee.api.connection.ProxiedPlayer;
 import net.md_5.bungee.api.event.LoginEvent;
+import net.md_5.bungee.api.event.ProxyPingEvent;
 import net.md_5.bungee.packet.Packet2Handshake;
 import net.md_5.bungee.packet.PacketFCEncryptionResponse;
 import net.md_5.bungee.packet.PacketFDEncryptionRequest;
@@ -102,14 +104,19 @@ public class InitialHandler implements Runnable, PendingConnection
                     } catch (IOException ex)
                     {
                     }
-                    Configuration conf = BungeeCord.getInstance().config;
+
+                    ServerPing pingevent = new ServerPing(BungeeCord.PROTOCOL_VERSION, BungeeCord.GAME_VERSION,
+                            listener.getMotd(), ProxyServer.getInstance().getPlayers().size(), listener.getMaxPlayers());
+
+                    ProxyServer.getInstance().getPluginManager().callEvent(new ProxyPingEvent(this, pingevent));
+
                     String ping = (newPing) ? ChatColor.COLOR_CHAR + "1"
-                            + "\00" + BungeeCord.PROTOCOL_VERSION
+                            + "\00" + pingevent.getProtocolVersion()
-                            + "\00" + BungeeCord.GAME_VERSION
+                            + "\00" + pingevent.getGameVersion()
-                            + "\00" + listener.getMotd()
+                            + "\00" + pingevent.getMotd()
-                            + "\00" + ProxyServer.getInstance().getPlayers().size()
+                            + "\00" + pingevent.getCurrentPlayers()
-                            + "\00" + listener.getMaxPlayers()
+                            + "\00" + pingevent.getMaxPlayers()
-                            : listener.getMotd() + ChatColor.COLOR_CHAR + ProxyServer.getInstance().getPlayers().size() + ChatColor.COLOR_CHAR + listener.getMaxPlayers();
+                            : pingevent.getMotd() + ChatColor.COLOR_CHAR + pingevent.getCurrentPlayers() + ChatColor.COLOR_CHAR + pingevent.getMaxPlayers();
                     throw new KickException(ping);
                 default:
                     if (id == 0xFA)

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

@@ -1,5 +1,7 @@
 package net.md_5.bungee;
 
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
 import java.io.OutputStream;
 import java.net.InetSocketAddress;
 import java.net.Socket;
@@ -118,9 +120,37 @@ public class ServerConnection extends GenericConnection implements Server
     }
 
     @Override
-    public void ping(Callback<ServerPing> callback)
+    public void ping(final Callback<ServerPing> callback)
     {
-        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
+        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();
     }
 
     @Override

proxy/src/main/java/net/md_5/bungee/packet/PacketInputStream.java

@@ -10,7 +10,7 @@ import net.md_5.mendax.datainput.DataInputPacketReader;
  * A specialized input stream to parse packets using the Mojang packet
  * definitions and then return them as a byte array.
  */
-public class PacketInputStream
+public class PacketInputStream implements AutoCloseable
 {
 
     private final DataInputStream dataInput;
@@ -35,6 +35,12 @@ public class PacketInputStream
         return tracker.out.toByteArray();
     }
 
+    @Override
+    public void close() throws Exception
+    {
+        dataInput.close();
+    }
+
     /**
      * Input stream which will wrap another stream and copy all bytes read to a
      * {@link ByteArrayOutputStream}.