Spigot 1.17 compatibility

bukkit/src/main/java/com/viaversion/viaversion/ViaVersionPlugin.java

@@ -109,7 +109,10 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform<Player>
 
         // Check if it's a spigot build with a protocol mod
         try {
-            NMSUtil.nms("PacketEncoder").getDeclaredField("version");
+            NMSUtil.nms(
+                    "PacketEncoder",
+                    "net.minecraft.network.PacketEncoder"
+            ).getDeclaredField("version");
             compatSpigotBuild = true;
         } catch (Exception e) {
             compatSpigotBuild = false;

bukkit/src/main/java/com/viaversion/viaversion/bukkit/classgenerator/ClassGenerator.java

@@ -65,8 +65,8 @@ public class ClassGenerator {
                 }
 
                 if (ViaVersionPlugin.getInstance().isCompatSpigotBuild()) {
-                    Class decodeSuper = NMSUtil.nms("PacketDecoder");
-                    Class encodeSuper = NMSUtil.nms("PacketEncoder");
+                    Class decodeSuper = NMSUtil.nms("PacketDecoder", "net.minecraft.network.PacketDecoder");
+                    Class encodeSuper = NMSUtil.nms("PacketEncoder", "net.minecraft.network.PacketEncoder");
                     // Generate the classes
                     addSpigotCompatibility(pool, BukkitDecodeHandler.class, decodeSuper);
                     addSpigotCompatibility(pool, BukkitEncodeHandler.class, encodeSuper);
@@ -209,7 +209,10 @@ public class ClassGenerator {
             pool.importPackage("protocolsupport.api.Connection.PacketListener");
             pool.importPackage("protocolsupport.api.Connection.PacketListener.PacketEvent");
             pool.importPackage("protocolsupport.protocol.ConnectionImpl");
-            pool.importPackage(NMSUtil.nms("PacketHandshakingInSetProtocol").getName());
+            pool.importPackage(NMSUtil.nms(
+                    "PacketHandshakingInSetProtocol",
+                    "net.minecraft.network.protocol.handshake.PacketHandshakingInSetProtocol"
+            ).getName());
             // Add connection reference field
             connectListenerClazz.addField(CtField.make("private ConnectionImpl connection;", connectListenerClazz));
             // Bake constructor
@@ -303,7 +306,10 @@ public class ClassGenerator {
 
     public static boolean shouldUseNewHandshakeVersionMethod() {
         try {
-            NMSUtil.nms("PacketHandshakingInSetProtocol").getMethod("getProtocolVersion");
+            NMSUtil.nms(
+                    "PacketHandshakingInSetProtocol",
+                    "net.minecraft.network.protocol.handshake.PacketHandshakingInSetProtocol"
+            ).getMethod("getProtocolVersion");
             return true;
         } catch (Exception e) {
             return false;

bukkit/src/main/java/com/viaversion/viaversion/bukkit/handlers/BukkitEncodeHandler.java

@@ -39,7 +39,12 @@ public class BukkitEncodeHandler extends MessageToByteEncoder implements ViaCode
 
     static {
         try {
-            versionField = NMSUtil.nms("PacketEncoder").getDeclaredField("version");
+            // Attempt to get any version info from the handler
+            versionField = NMSUtil.nms(
+                    "PacketEncoder",
+                    "net.minecraft.network.PacketEncoder"
+            ).getDeclaredField("version");
+
             versionField.setAccessible(true);
         } catch (Exception e) {
             // Not compat version

bukkit/src/main/java/com/viaversion/viaversion/bukkit/platform/BukkitViaInjector.java

@@ -204,9 +204,15 @@ public class BukkitViaInjector implements ViaInjector {
         }
 
         try {
-            Class<?> serverClazz = NMSUtil.nms("MinecraftServer");
+            // Grab a static instance of the server
+            Class<?> serverClazz = NMSUtil.nms("MinecraftServer", "net.minecraft.server.MinecraftServer");
             Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
-            Class<?> pingClazz = NMSUtil.nms("ServerPing");
+
+            // Grab the ping class and find the field to access it
+            Class<?> pingClazz = NMSUtil.nms(
+                    "ServerPing",
+                    "net.minecraft.network.protocol.status.ServerPing"
+            );
             Object ping = null;
             // Search for ping method
             for (Field f : serverClazz.getDeclaredFields()) {
@@ -259,7 +265,10 @@ public class BukkitViaInjector implements ViaInjector {
     }
 
     public static Object getServerConnection() throws Exception {
-        Class<?> serverClazz = NMSUtil.nms("MinecraftServer");
+        Class<?> serverClazz = NMSUtil.nms(
+                "MinecraftServer",
+                "net.minecraft.server.MinecraftServer"
+        );
         Object server = ReflectionUtil.invokeStatic(serverClazz, "getServer");
         Object connection = null;
         for (Method m : serverClazz.getDeclaredMethods()) {

bukkit/src/main/java/com/viaversion/viaversion/bukkit/util/NMSUtil.java

@@ -26,7 +26,10 @@ public class NMSUtil {
 
     private static boolean loadDebugProperty() {
         try {
-            Class<?> serverClass = nms("MinecraftServer");
+            Class<?> serverClass = nms(
+                    "MinecraftServer",
+                    "net.minecraft.server.MinecraftServer"
+            );
             Object server = serverClass.getDeclaredMethod("getServer").invoke(null);
             return (boolean) serverClass.getMethod("isDebugging").invoke(server);
         } catch (ReflectiveOperationException e) {
@@ -38,6 +41,14 @@ public class NMSUtil {
         return Class.forName(NMS + "." + className);
     }
 
+    public static Class<?> nms(String className, String fallbackFullClassName) throws ClassNotFoundException {
+        try {
+            return Class.forName(NMS + "." + className);
+        } catch (ClassNotFoundException ignored) {
+            return Class.forName(fallbackFullClassName);
+        }
+    }
+
     public static Class<?> obc(String className) throws ClassNotFoundException {
         return Class.forName(BASE + "." + className);
     }