Migrate to using built-in http client (#1192)

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

@@ -71,6 +71,7 @@ import io.netty.channel.EventLoopGroup;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.InetSocketAddress;
+import java.net.http.HttpClient;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.security.AccessController;
@@ -143,6 +144,7 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
 
   private final ConnectionManager cm;
   private final ProxyOptions options;
+  private final HttpClient httpClient;
   private @MonotonicNonNull VelocityConfiguration configuration;
   private @MonotonicNonNull KeyPair serverKeyPair;
   private final ServerMap servers;
@@ -168,6 +170,7 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
     scheduler = new VelocityScheduler(pluginManager);
     console = new VelocityConsole(this);
     cm = new ConnectionManager(this);
+    httpClient = HttpClient.newHttpClient();
     servers = new ServerMap(this);
     serverListPingHandler = new ServerListPingHandler(this);
     this.options = options;
@@ -591,6 +594,10 @@ public class VelocityServer implements ProxyServer, ForwardingAudience {
     this.cm.closeEndpoints(false);
   }
 
+  public HttpClient getHttpClient() {
+    return httpClient;
+  }
+
   public AsyncHttpClient getAsyncHttpClient() {
     return cm.getHttpClient();
   }

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

@@ -42,19 +42,19 @@ import com.velocitypowered.proxy.protocol.packet.LoginPluginResponse;
 import com.velocitypowered.proxy.protocol.packet.ServerLogin;
 import io.netty.buffer.ByteBuf;
 import java.net.InetSocketAddress;
+import java.net.URI;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
 import java.security.GeneralSecurityException;
 import java.security.KeyPair;
 import java.security.MessageDigest;
 import java.util.Arrays;
 import java.util.Optional;
-import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.format.NamedTextColor;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.asynchttpclient.ListenableFuture;
-import org.asynchttpclient.Response;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
@@ -209,14 +209,20 @@ public class InitialLoginSessionHandler implements MinecraftSessionHandler {
         url += "&ip=" + urlFormParameterEscaper().escape(playerIp);
       }
 
-      ListenableFuture<Response> hasJoinedResponse = server.getAsyncHttpClient().prepareGet(url)
-          .execute();
-      hasJoinedResponse.addListener(() -> {
+      HttpRequest httpRequest = HttpRequest.newBuilder().uri(URI.create(url)).build();
+      server.getHttpClient().sendAsync(httpRequest, HttpResponse.BodyHandlers.ofString())
+          .whenCompleteAsync((response, throwable) -> {
             if (mcConnection.isClosed()) {
               // The player disconnected after we authenticated them.
               return;
             }
 
+            if (throwable != null) {
+              logger.error("Unable to authenticate player", throwable);
+              inbound.disconnect(Component.translatable("multiplayer.disconnect.authservers_down"));
+              return;
+            }
+
             // Go ahead and enable encryption. Once the client sends EncryptionResponse, encryption
             // is enabled.
             try {
@@ -229,10 +235,8 @@ public class InitialLoginSessionHandler implements MinecraftSessionHandler {
               return;
             }
 
-        try {
-          Response profileResponse = hasJoinedResponse.get();
-          if (profileResponse.getStatusCode() == 200) {
-            final GameProfile profile = GENERAL_GSON.fromJson(profileResponse.getResponseBody(),
+            if (response.statusCode() == 200) {
+              final GameProfile profile = GENERAL_GSON.fromJson(response.body(),
                   GameProfile.class);
               // Not so fast, now we verify the public key for 1.19.1+
               if (inbound.getIdentifiedKey() != null
@@ -247,7 +251,7 @@ public class InitialLoginSessionHandler implements MinecraftSessionHandler {
               // All went well, initialize the session.
               mcConnection.setActiveSessionHandler(StateRegistry.LOGIN,
                   new AuthSessionHandler(server, inbound, profile, true));
-          } else if (profileResponse.getStatusCode() == 204) {
+            } else if (response.statusCode() == 204) {
               // Apparently an offline-mode user logged onto this online-mode proxy.
               inbound.disconnect(
                   Component.translatable("velocity.error.online-mode-only", NamedTextColor.RED));
@@ -255,16 +259,9 @@ public class InitialLoginSessionHandler implements MinecraftSessionHandler {
               // Something else went wrong
               logger.error(
                   "Got an unexpected error code {} whilst contacting Mojang to log in {} ({})",
-                profileResponse.getStatusCode(), login.getUsername(), playerIp);
+                  response.sslSession(), login.getUsername(), playerIp);
               inbound.disconnect(Component.translatable("multiplayer.disconnect.authservers_down"));
             }
-        } catch (ExecutionException e) {
-          logger.error("Unable to authenticate with Mojang", e);
-          inbound.disconnect(Component.translatable("multiplayer.disconnect.authservers_down"));
-        } catch (InterruptedException e) {
-          // not much we can do usefully
-          Thread.currentThread().interrupt();
-        }
           }, mcConnection.eventLoop());
     } catch (GeneralSecurityException e) {
       logger.error("Unable to enable encryption", e);