Use translatable components like vanilla and cleanup type casts (#831)

* Use translatable components like vanilla and cleanup type casts

Just a few messages becoming dynamic using translatable components like vanilla instead of being hardcoded.

* Use checkerframework

* Readd disconnect string methods

* Do not make nullable

example/src/main/java/org/geysermc/mcprotocollib/network/example/ClientSessionListener.java

@@ -1,5 +1,6 @@
 package org.geysermc.mcprotocollib.network.example;
 
+import net.kyori.adventure.text.Component;
 import org.geysermc.mcprotocollib.network.Session;
 import org.geysermc.mcprotocollib.network.event.session.ConnectedEvent;
 import org.geysermc.mcprotocollib.network.event.session.DisconnectedEvent;
@@ -14,23 +15,23 @@ public class ClientSessionListener extends SessionAdapter {
 
     @Override
     public void packetReceived(Session session, Packet packet) {
-        if (packet instanceof PingPacket) {
-            String id = ((PingPacket) packet).getPingId();
+        if (packet instanceof PingPacket pingPacket) {
+            String id = pingPacket.getPingId();
 
             log.info("CLIENT Received: {}", id);
 
             if (id.equals("hello")) {
                 session.send(new PingPacket("exit"));
             } else if (id.equals("exit")) {
-                session.disconnect("Finished");
+                session.disconnect(Component.text("Finished"));
             }
         }
     }
 
     @Override
     public void packetSent(Session session, Packet packet) {
-        if (packet instanceof PingPacket) {
-            log.info("CLIENT Sent: {}", ((PingPacket) packet).getPingId());
+        if (packet instanceof PingPacket pingPacket) {
+            log.info("CLIENT Sent: {}", pingPacket.getPingId());
         }
     }
 

example/src/main/java/org/geysermc/mcprotocollib/network/example/ServerSessionListener.java

@@ -14,16 +14,16 @@ public class ServerSessionListener extends SessionAdapter {
 
     @Override
     public void packetReceived(Session session, Packet packet) {
-        if (packet instanceof PingPacket) {
-            log.info("SERVER Received: {}", ((PingPacket) packet).getPingId());
+        if (packet instanceof PingPacket pingPacket) {
+            log.info("SERVER Received: {}", pingPacket.getPingId());
             session.send(packet);
         }
     }
 
     @Override
     public void packetSent(Session session, Packet packet) {
-        if (packet instanceof PingPacket) {
-            log.info("SERVER Sent: {}", ((PingPacket) packet).getPingId());
+        if (packet instanceof PingPacket pingPacket) {
+            log.info("SERVER Sent: {}", pingPacket.getPingId());
         }
     }
 

example/src/main/java/org/geysermc/mcprotocollib/protocol/example/MinecraftProtocolTest.java

@@ -112,9 +112,9 @@ public void sessionAdded(SessionAddedEvent event) {
                     event.getSession().addListener(new SessionAdapter() {
                         @Override
                         public void packetReceived(Session session, Packet packet) {
-                            if (packet instanceof ServerboundChatPacket) {
+                            if (packet instanceof ServerboundChatPacket chatPacket) {
                                 GameProfile profile = event.getSession().getFlag(MinecraftConstants.PROFILE_KEY);
-                                log.info("{}: {}", profile.getName(), ((ServerboundChatPacket) packet).getMessage());
+                                log.info("{}: {}", profile.getName(), chatPacket.getMessage());
 
                                 Component msg = Component.text("Hello, ")
                                         .color(NamedTextColor.GREEN)
@@ -207,10 +207,10 @@ private static void login() {
             public void packetReceived(Session session, Packet packet) {
                 if (packet instanceof ClientboundLoginPacket) {
                     session.send(new ServerboundChatPacket("Hello, this is a test of MCProtocolLib.", Instant.now().toEpochMilli(), 0L, null, 0, new BitSet()));
-                } else if (packet instanceof ClientboundSystemChatPacket) {
-                    Component message = ((ClientboundSystemChatPacket) packet).getContent();
+                } else if (packet instanceof ClientboundSystemChatPacket systemChatPacket) {
+                    Component message = systemChatPacket.getContent();
                     log.info("Received Message: {}", message);
-                    session.disconnect("Finished");
+                    session.disconnect(Component.text("Finished"));
                 }
             }
 

protocol/src/main/java/org/geysermc/mcprotocollib/network/AbstractServer.java

@@ -1,5 +1,6 @@
 package org.geysermc.mcprotocollib.network;
 
+import net.kyori.adventure.text.Component;
 import org.geysermc.mcprotocollib.network.event.server.ServerBoundEvent;
 import org.geysermc.mcprotocollib.network.event.server.ServerClosedEvent;
 import org.geysermc.mcprotocollib.network.event.server.ServerClosingEvent;
@@ -119,7 +120,7 @@ public void addSession(Session session) {
     public void removeSession(Session session) {
         this.sessions.remove(session);
         if (session.isConnected()) {
-            session.disconnect("Connection closed.");
+            session.disconnect(Component.translatable("disconnect.endOfStream"));
         }
 
         this.callEvent(new SessionRemovedEvent(this, session));
@@ -164,7 +165,7 @@ public void close(boolean wait, Runnable callback) {
         this.callEvent(new ServerClosingEvent(this));
         for (Session session : this.getSessions()) {
             if (session.isConnected()) {
-                session.disconnect("Server closed.");
+                session.disconnect(Component.translatable("multiplayer.disconnect.server_shutdown"));
             }
         }
 

protocol/src/main/java/org/geysermc/mcprotocollib/network/Session.java

@@ -1,6 +1,7 @@
 package org.geysermc.mcprotocollib.network;
 
 import net.kyori.adventure.text.Component;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.geysermc.mcprotocollib.network.codec.PacketCodecHelper;
 import org.geysermc.mcprotocollib.network.crypt.PacketEncryption;
@@ -261,31 +262,43 @@ public interface Session {
 
     /**
      * Disconnects the session.
+     * This method just wraps the reason into a {@link Component}.
+     * It is recommended to use Components instead as they provide more flexibility.
      *
      * @param reason Reason for disconnecting.
+     * @see #disconnect(String, Throwable)
      */
-    void disconnect(@Nullable String reason);
+    default void disconnect(@NonNull String reason) {
+        this.disconnect(reason, null);
+    }
 
     /**
      * Disconnects the session.
+     * This method just wraps the reason into a {@link Component}.
+     * It is recommended to use Components instead as they provide more flexibility.
      *
      * @param reason Reason for disconnecting.
      * @param cause Throwable responsible for disconnecting.
+     * @see #disconnect(Component, Throwable)
      */
-    void disconnect(@Nullable String reason, Throwable cause);
+    default void disconnect(@NonNull String reason, @Nullable Throwable cause) {
+        this.disconnect(Component.text(reason), cause);
+    }
 
     /**
      * Disconnects the session.
      *
      * @param reason Reason for disconnecting.
      */
-    void disconnect(@Nullable Component reason);
+    default void disconnect(@NonNull Component reason) {
+        this.disconnect(reason, null);
+    }
 
     /**
      * Disconnects the session.
      *
      * @param reason Reason for disconnecting.
      * @param cause Throwable responsible for disconnecting.
      */
-    void disconnect(@Nullable Component reason, Throwable cause);
+    void disconnect(@NonNull Component reason, @Nullable Throwable cause);
 }

protocol/src/main/java/org/geysermc/mcprotocollib/network/tcp/TcpClientSession.java

@@ -28,8 +28,8 @@
 import io.netty.resolver.dns.DnsNameResolver;
 import io.netty.resolver.dns.DnsNameResolverBuilder;
 import io.netty.util.concurrent.DefaultThreadFactory;
-import org.geysermc.mcprotocollib.network.ProxyInfo;
 import org.geysermc.mcprotocollib.network.BuiltinFlags;
+import org.geysermc.mcprotocollib.network.ProxyInfo;
 import org.geysermc.mcprotocollib.network.codec.PacketCodecHelper;
 import org.geysermc.mcprotocollib.network.helper.TransportHelper;
 import org.geysermc.mcprotocollib.network.packet.PacketProtocol;
@@ -256,11 +256,6 @@ public void channelActive(ChannelHandlerContext ctx) throws Exception {
         }
     }
 
-    @Override
-    public void disconnect(String reason, Throwable cause) {
-        super.disconnect(reason, cause);
-    }
-
     private static void createTcpEventLoopGroup() {
         if (EVENT_LOOP_GROUP != null) {
             return;

protocol/src/main/java/org/geysermc/mcprotocollib/network/tcp/TcpSession.java

@@ -3,17 +3,15 @@
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFutureListener;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.DefaultEventLoopGroup;
 import io.netty.channel.EventLoop;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.SimpleChannelInboundHandler;
-import io.netty.handler.timeout.ReadTimeoutException;
 import io.netty.handler.timeout.ReadTimeoutHandler;
-import io.netty.handler.timeout.WriteTimeoutException;
 import io.netty.handler.timeout.WriteTimeoutHandler;
 import io.netty.util.concurrent.DefaultThreadFactory;
 import net.kyori.adventure.text.Component;
+import org.checkerframework.checker.nullness.qual.NonNull;
 import org.checkerframework.checker.nullness.qual.Nullable;
 import org.geysermc.mcprotocollib.network.Flag;
 import org.geysermc.mcprotocollib.network.Session;
@@ -27,14 +25,14 @@
 import org.geysermc.mcprotocollib.network.packet.Packet;
 import org.geysermc.mcprotocollib.network.packet.PacketProtocol;
 
-import java.net.ConnectException;
 import java.net.SocketAddress;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 public abstract class TcpSession extends SimpleChannelInboundHandler<Packet> implements Session {
     /**
@@ -279,22 +277,7 @@ public void send(Packet packet) {
     }
 
     @Override
-    public void disconnect(String reason) {
-        this.disconnect(Component.text(reason));
-    }
-
-    @Override
-    public void disconnect(String reason, Throwable cause) {
-        this.disconnect(Component.text(reason), cause);
-    }
-
-    @Override
-    public void disconnect(Component reason) {
-        this.disconnect(reason, null);
-    }
-
-    @Override
-    public void disconnect(final Component reason, final Throwable cause) {
+    public void disconnect(@NonNull Component reason, @Nullable Throwable cause) {
         if (this.disconnected) {
             return;
         }
@@ -303,11 +286,9 @@ public void disconnect(final Component reason, final Throwable cause) {
 
         if (this.channel != null && this.channel.isOpen()) {
             this.callEvent(new DisconnectingEvent(this, reason, cause));
-            this.channel.flush().close().addListener((ChannelFutureListener) future ->
-                    callEvent(new DisconnectedEvent(TcpSession.this,
-                            reason != null ? reason : Component.text("Connection closed."), cause)));
+            this.channel.flush().close().addListener((ChannelFutureListener) future -> callEvent(new DisconnectedEvent(TcpSession.this, reason, cause)));
         } else {
-            this.callEvent(new DisconnectedEvent(this, reason != null ? reason : Component.text("Connection closed."), cause));
+            this.callEvent(new DisconnectedEvent(this, reason, cause));
         }
     }
 
@@ -385,21 +366,17 @@ public void channelActive(ChannelHandlerContext ctx) throws Exception {
     @Override
     public void channelInactive(ChannelHandlerContext ctx) throws Exception {
         if (ctx.channel() == this.channel) {
-            this.disconnect("Connection closed.");
+            this.disconnect(Component.translatable("disconnect.endOfStream"));
         }
     }
 
     @Override
     public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
-        String message;
-        if (cause instanceof ConnectTimeoutException || (cause instanceof ConnectException && cause.getMessage().contains("connection timed out"))) {
-            message = "Connection timed out.";
-        } else if (cause instanceof ReadTimeoutException) {
-            message = "Read timed out.";
-        } else if (cause instanceof WriteTimeoutException) {
-            message = "Write timed out.";
+        Component message;
+        if (cause instanceof TimeoutException) {
+            message = Component.translatable("disconnect.timeout");
         } else {
-            message = cause.toString();
+            message = Component.translatable("disconnect.genericReason", Component.text("Internal Exception: " + cause));
         }
 
         this.disconnect(message, cause);

protocol/src/main/java/org/geysermc/mcprotocollib/protocol/ClientListener.java

@@ -3,6 +3,7 @@
 import lombok.AllArgsConstructor;
 import lombok.NonNull;
 import lombok.SneakyThrows;
+import net.kyori.adventure.text.Component;
 import org.geysermc.mcprotocollib.auth.GameProfile;
 import org.geysermc.mcprotocollib.auth.SessionService;
 import org.geysermc.mcprotocollib.network.Session;
@@ -77,10 +78,12 @@ public void packetReceived(Session session, Packet packet) {
 
                 SessionService sessionService = session.getFlag(MinecraftConstants.SESSION_SERVICE_KEY, new SessionService());
                 String serverId = SessionService.getServerId(helloPacket.getServerId(), helloPacket.getPublicKey(), key);
+
+                // TODO: Add generic error, disabled multiplayer and banned from playing online errors
                 try {
                     sessionService.joinServer(profile, accessToken, serverId);
                 } catch (IOException e) {
-                    session.disconnect("Login failed: Authentication error: " + e.getMessage(), e);
+                    session.disconnect(Component.translatable("disconnect.loginFailedInfo", Component.text(e.getMessage())), e);
                     return;
                 }
 
@@ -109,7 +112,7 @@ public void packetReceived(Session session, Packet packet) {
                     handler.handle(session, time);
                 }
 
-                session.disconnect("Finished");
+                session.disconnect(Component.translatable("multiplayer.status.finished"));
             }
         } else if (protocol.getState() == ProtocolState.GAME) {
             if (packet instanceof ClientboundKeepAlivePacket keepAlivePacket && session.getFlag(MinecraftConstants.AUTOMATIC_KEEP_ALIVE_MANAGEMENT, true)) {
@@ -122,7 +125,7 @@ public void packetReceived(Session session, Packet packet) {
                 if (session.getFlag(MinecraftConstants.FOLLOW_TRANSFERS, true)) {
                     TcpClientSession newSession = new TcpClientSession(transferPacket.getHost(), transferPacket.getPort(), session.getPacketProtocol());
                     newSession.setFlags(session.getFlags());
-                    session.disconnect("Transferring");
+                    session.disconnect(Component.translatable("disconnect.transfer"));
                     newSession.connect(true, true);
                 }
             }
@@ -137,7 +140,7 @@ public void packetReceived(Session session, Packet packet) {
                 if (session.getFlag(MinecraftConstants.FOLLOW_TRANSFERS, true)) {
                     TcpClientSession newSession = new TcpClientSession(transferPacket.getHost(), transferPacket.getPort(), session.getPacketProtocol());
                     newSession.setFlags(session.getFlags());
-                    session.disconnect("Transferring");
+                    session.disconnect(Component.translatable("disconnect.transfer"));
                     newSession.connect(true, true);
                 }
             }

protocol/src/main/java/org/geysermc/mcprotocollib/protocol/ServerListener.java

@@ -98,15 +98,15 @@ public void packetReceived(Session session, Packet packet) {
                     case STATUS -> protocol.setState(ProtocolState.STATUS);
                     case TRANSFER -> {
                         if (!session.getFlag(MinecraftConstants.ACCEPT_TRANSFERS_KEY, false)) {
-                            session.disconnect("Server does not accept transfers.");
+                            session.disconnect(Component.translatable("multiplayer.disconnect.transfers_disabled"));
                         }
                     }
                     case LOGIN -> {
                         protocol.setState(ProtocolState.LOGIN);
                         if (intentionPacket.getProtocolVersion() > protocol.getCodec().getProtocolVersion()) {
-                            session.disconnect("Outdated server! I'm still on " + protocol.getCodec().getMinecraftVersion() + ".");
+                            session.disconnect(Component.translatable("multiplayer.disconnect.incompatible", Component.text(protocol.getCodec().getMinecraftVersion())));
                         } else if (intentionPacket.getProtocolVersion() < protocol.getCodec().getProtocolVersion()) {
-                            session.disconnect("Outdated client! Please use " + protocol.getCodec().getMinecraftVersion() + ".");
+                            session.disconnect(Component.translatable("multiplayer.disconnect.outdated_client", Component.text(protocol.getCodec().getMinecraftVersion())));
                         }
                     }
                     default -> throw new UnsupportedOperationException("Invalid client intent: " + intentionPacket.getIntent());
@@ -125,8 +125,7 @@ public void packetReceived(Session session, Packet packet) {
                 PrivateKey privateKey = KEY_PAIR.getPrivate();
 
                 if (!Arrays.equals(this.challenge, keyPacket.getEncryptedChallenge(privateKey))) {
-                    session.disconnect("Invalid challenge!");
-                    return;
+                    throw new IllegalStateException("Protocol error");
                 }
 
                 SecretKey key = keyPacket.getSecretKey(privateKey);
@@ -183,6 +182,7 @@ public void packetReceived(Session session, Packet packet) {
                 protocol.setState(ProtocolState.CONFIGURATION);
             } else if (packet instanceof ServerboundPingRequestPacket pingRequestPacket) {
                 session.send(new ClientboundPongResponsePacket(pingRequestPacket.getPingTime()));
+                session.disconnect(Component.translatable("multiplayer.status.request_handled"));
             }
         } else if (protocol.getState() == ProtocolState.CONFIGURATION) {
             if (packet instanceof ServerboundFinishConfigurationPacket) {
@@ -230,12 +230,13 @@ public void run() {
                 try {
                     profile = sessionService.getProfileByServer(username, SessionService.getServerId(SERVER_ID, KEY_PAIR.getPublic(), this.key));
                 } catch (IOException e) {
-                    this.session.disconnect("Failed to make session service request.", e);
+                    session.disconnect(Component.translatable("multiplayer.disconnect.authservers_down"), e);
                     return;
                 }
 
                 if (profile == null) {
-                    this.session.disconnect("Failed to verify username.");
+                    session.disconnect(Component.translatable("multiplayer.disconnect.unverified_username"));
+                    return;
                 }
             } else {
                 profile = new GameProfile(UUID.nameUUIDFromBytes(("OfflinePlayer:" + username).getBytes()), username);