Respect try list in velocity.toml

src/main/java/com/velocitypowered/proxy/VelocityServer.java

@@ -5,7 +5,10 @@ import com.google.gson.GsonBuilder;
 import com.velocitypowered.network.ConnectionManager;
 import com.velocitypowered.proxy.config.VelocityConfiguration;
 import com.velocitypowered.proxy.connection.http.NettyHttpClient;
+import com.velocitypowered.proxy.data.ServerInfo;
+import com.velocitypowered.proxy.util.AddressUtil;
 import com.velocitypowered.proxy.util.EncryptionUtils;
+import com.velocitypowered.proxy.util.ServerMap;
 import io.netty.bootstrap.Bootstrap;
 import net.kyori.text.Component;
 import net.kyori.text.serializer.GsonComponentSerializer;
@@ -18,6 +21,8 @@ import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.security.KeyPair;
+import java.util.HashMap;
+import java.util.Map;
 
 public class VelocityServer {
     private static final Logger logger = LogManager.getLogger(VelocityServer.class);
@@ -30,6 +35,7 @@ public class VelocityServer {
     private VelocityConfiguration configuration;
     private NettyHttpClient httpClient;
     private KeyPair serverKeyPair;
+    private final ServerMap servers = new ServerMap();
 
     private VelocityServer() {
     }
@@ -67,6 +73,11 @@ public class VelocityServer {
             logger.error("Unable to load your velocity.toml. The server will shut down.", e);
             System.exit(1);
         }
+
+        for (Map.Entry<String, String> entry : configuration.getServers().entrySet()) {
+            servers.register(new ServerInfo(entry.getKey(), AddressUtil.parseAddress(entry.getValue())));
+        }
+
         serverKeyPair = EncryptionUtils.createRsaKeyPair(1024);
 
         httpClient = new NettyHttpClient(this);
@@ -74,6 +85,10 @@ public class VelocityServer {
         this.cm.bind(configuration.getBind());
     }
 
+    public ServerMap getServers() {
+        return servers;
+    }
+
     public Bootstrap initializeGenericBootstrap() {
         return this.cm.createWorker();
     }

src/main/java/com/velocitypowered/proxy/connection/client/ConnectedPlayer.java

@@ -1,5 +1,7 @@
 package com.velocitypowered.proxy.connection.client;
 
+import com.google.common.base.Preconditions;
+import com.velocitypowered.proxy.VelocityServer;
 import com.velocitypowered.proxy.connection.MinecraftConnectionAssociation;
 import com.velocitypowered.proxy.data.GameProfile;
 import com.velocitypowered.proxy.protocol.packets.Chat;
@@ -19,6 +21,8 @@ import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 import java.net.InetSocketAddress;
+import java.util.List;
+import java.util.Optional;
 import java.util.UUID;
 
 public class ConnectedPlayer implements MinecraftConnectionAssociation {
@@ -28,6 +32,7 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation {
 
     private final GameProfile profile;
     private final MinecraftConnection connection;
+    private int tryIndex = 0;
     private ServerConnection connectedServer;
     private ClientSettings clientSettings;
 
@@ -106,7 +111,27 @@ public class ConnectedPlayer implements MinecraftConnectionAssociation {
         }
     }
 
+    public Optional<ServerInfo> getNextServerToTry() {
+        List<String> serversToTry = VelocityServer.getServer().getConfiguration().getAttemptConnectionOrder();
+        if (tryIndex >= serversToTry.size()) {
+            return Optional.empty();
+        }
+
+        String toTryName = serversToTry.get(tryIndex);
+        tryIndex++;
+        return VelocityServer.getServer().getServers().getServer(toTryName);
+    }
+
+    public void connect(ServerInfo info) {
+        Preconditions.checkNotNull(info, "info");
+        ServerConnection connection = new ServerConnection(info, this, VelocityServer.getServer());
+        connection.connect();
+    }
+
     public void setConnectedServer(ServerConnection serverConnection) {
+        if (this.connectedServer != null && !serverConnection.getServerInfo().equals(connectedServer.getServerInfo())) {
+            this.tryIndex = 0;
+        }
         this.connectedServer = serverConnection;
     }
 

src/main/java/com/velocitypowered/proxy/connection/client/LoginSessionHandler.java

@@ -12,6 +12,8 @@ import com.velocitypowered.proxy.connection.backend.ServerConnection;
 import com.velocitypowered.proxy.data.ServerInfo;
 import com.velocitypowered.proxy.util.EncryptionUtils;
 import com.velocitypowered.proxy.util.UuidUtils;
+import net.kyori.text.TextComponent;
+import net.kyori.text.format.TextColor;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -20,6 +22,7 @@ import java.net.URL;
 import java.security.GeneralSecurityException;
 import java.security.KeyPair;
 import java.util.Arrays;
+import java.util.Optional;
 import java.util.concurrent.ThreadLocalRandom;
 
 public class LoginSessionHandler implements MinecraftSessionHandler {
@@ -95,6 +98,14 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
     }
 
     private void handleSuccessfulLogin(GameProfile profile) {
+        // Initiate a regular connection and move over to it.
+        ConnectedPlayer player = new ConnectedPlayer(profile, inbound);
+        Optional<ServerInfo> toTry = player.getNextServerToTry();
+        if (!toTry.isPresent()) {
+            player.close(TextComponent.of("No available servers", TextColor.RED));
+            return;
+        }
+
         inbound.write(new SetCompression(256));
         inbound.setCompressionThreshold(256);
 
@@ -103,15 +114,10 @@ public class LoginSessionHandler implements MinecraftSessionHandler {
         success.setUuid(profile.idAsUuid());
         inbound.write(success);
 
-        // Initiate a regular connection and move over to it.
-        ConnectedPlayer player = new ConnectedPlayer(profile, inbound);
         logger.info("{} has connected", player);
         inbound.setAssociation(player);
-        ServerInfo info = new ServerInfo("test", new InetSocketAddress("localhost", 25565));
-        ServerConnection connection = new ServerConnection(info, player, VelocityServer.getServer());
-
         inbound.setState(StateRegistry.PLAY);
         inbound.setSessionHandler(new InitialConnectSessionHandler(player));
-        connection.connect();
+        player.connect(toTry.get());
     }
 }

src/main/java/com/velocitypowered/proxy/data/ServerInfo.java

@@ -1,22 +1,24 @@
 package com.velocitypowered.proxy.data;
 
+import com.google.common.base.Preconditions;
+
 import java.net.InetSocketAddress;
 import java.util.Objects;
 
-public class ServerInfo {
+public final class ServerInfo {
     private final String name;
     private final InetSocketAddress address;
 
     public ServerInfo(String name, InetSocketAddress address) {
-        this.name = name;
+        this.name = Preconditions.checkNotNull(name, "name");
-        this.address = address;
+        this.address = Preconditions.checkNotNull(address, "address");
     }
 
-    public String getName() {
+    public final String getName() {
         return name;
     }
 
-    public InetSocketAddress getAddress() {
+    public final InetSocketAddress getAddress() {
         return address;
     }
 
@@ -29,7 +31,7 @@ public class ServerInfo {
     }
 
     @Override
-    public boolean equals(Object o) {
+    public final boolean equals(Object o) {
         if (this == o) return true;
         if (o == null || getClass() != o.getClass()) return false;
         ServerInfo that = (ServerInfo) o;
@@ -38,7 +40,7 @@ public class ServerInfo {
     }
 
     @Override
-    public int hashCode() {
+    public final int hashCode() {
         return Objects.hash(name, address);
     }
 }

src/main/java/com/velocitypowered/proxy/util/ServerMap.java

@@ -0,0 +1,28 @@
+package com.velocitypowered.proxy.util;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableList;
+import com.velocitypowered.proxy.data.ServerInfo;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+public class ServerMap {
+    private final Map<String, ServerInfo> servers = new HashMap<>();
+
+    public Optional<ServerInfo> getServer(String name) {
+        Preconditions.checkNotNull(name, "name");
+        return Optional.ofNullable(servers.get(name.toLowerCase()));
+    }
+
+    public Collection<ServerInfo> getAllServers() {
+        return ImmutableList.copyOf(servers.values());
+    }
+
+    public void register(ServerInfo info) {
+        Preconditions.checkNotNull(info, "info");
+        servers.put(info.getName(), info);
+    }
+}