Add 1.17 support to TinyProtocol (#194)

TinyProtocol/src/main/java/com/comphenix/tinyprotocol/Reflection.java

@@ -3,6 +3,8 @@ package com.comphenix.tinyprotocol;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
 import java.util.Arrays;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -177,6 +179,31 @@ public final class Reflection {
 		throw new IllegalArgumentException("Cannot find field with type " + fieldType);
 	}
 
+	/**
+	 * Retrieves a field with a given type and parameters. This is most useful
+	 * when dealing with Collections.
+	 *
+	 * @param target the target class.
+	 * @param fieldType Type of the field
+	 * @param params Variable length array of type parameters
+	 * @return The field
+	 *
+	 * @throws IllegalArgumentException If the field cannot be found
+	 */
+	public static Field getParameterizedField(Class<?> target, Class<?> fieldType, Class<?>... params) {
+		for (Field field : target.getDeclaredFields()) {
+			if (field.getType().equals(fieldType)) {
+				Type type = field.getGenericType();
+				if (type instanceof ParameterizedType) {
+					if (Arrays.equals(((ParameterizedType) type).getActualTypeArguments(), params))
+						return field;
+				}
+			}
+		}
+
+		throw new IllegalArgumentException("Unable to find a field with type " + fieldType + " and params " + Arrays.toString(params));
+	}
+
 	/**
 	 * Search for the first publicly and privately defined method of the given name and parameter count.
 	 * 
@@ -301,6 +328,23 @@ public final class Reflection {
 		return clazz;
 	}
 
+	/**
+	 * Retrieve a class from its full name with alternatives, without knowing its type on compile time.
+	 * <p>
+	 * This is useful when looking up fields by a NMS or OBC type.
+	 * <p>
+	 * 
+	 * @see {@link #getClass()} for more information.
+	 * @param lookupName - the class name with variables.
+	 * @param aliases - alternative names for this class.
+	 * @return The class.
+	 */
+	public static Class<Object> getUntypedClass(String lookupName, String... aliases) {
+		@SuppressWarnings({ "rawtypes", "unchecked" })
+		Class<Object> clazz = (Class) getClass(lookupName, aliases);
+		return clazz;
+	}
+
 	/**
 	 * Retrieve a class from its full name.
 	 * <p>
@@ -333,6 +377,61 @@ public final class Reflection {
 		return getCanonicalClass(expandVariables(lookupName));
 	}
 
+	/**
+	 * Retrieve the first class that matches the full class name.
+	 * <p>
+	 * Strings enclosed with curly brackets - such as {TEXT} - will be replaced according to the following table:
+	 * <p>
+	 * <table border="1">
+	 * <tr>
+	 * <th>Variable</th>
+	 * <th>Content</th>
+	 * </tr>
+	 * <tr>
+	 * <td>{nms}</td>
+	 * <td>Actual package name of net.minecraft.server.VERSION</td>
+	 * </tr>
+	 * <tr>
+	 * <td>{obc}</td>
+	 * <td>Actual pacakge name of org.bukkit.craftbukkit.VERSION</td>
+	 * </tr>
+	 * <tr>
+	 * <td>{version}</td>
+	 * <td>The current Minecraft package VERSION, if any.</td>
+	 * </tr>
+	 * </table>
+	 * 
+	 * @param lookupName - the class name with variables.
+	 * @param aliases - alternative names for this class.
+	 * @return Class object.
+	 * @throws RuntimeException If we are unable to find any of the given classes.
+	 */
+	public static Class<?> getClass(String lookupName, String... aliases) {
+		try {
+			// Try the main class first
+			return getClass(lookupName);
+		} catch (RuntimeException e) {
+			Class<?> success = null;
+
+			// Try every alias too
+			for (String alias : aliases) {
+				try {
+					success = getClass(alias);
+					break;
+				} catch (RuntimeException e1) {
+					// e1.printStackTrace();
+				}
+			}
+
+			if (success != null) {
+				return success;
+			} else {
+				// Hack failed
+				throw new RuntimeException(String.format("Unable to find %s (%s)", lookupName, String.join(",", aliases)));
+			}
+		}
+	}
+
 	/**
 	 * Retrieve a class in the net.minecraft.server.VERSION.* package.
 	 * 

TinyProtocol/src/main/java/com/comphenix/tinyprotocol/TinyProtocol.java

@@ -9,6 +9,7 @@ import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
 
+import java.lang.reflect.Field;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -44,21 +45,25 @@ import com.mojang.authlib.GameProfile;
 public abstract class TinyProtocol {
 	private static final AtomicInteger ID = new AtomicInteger(0);
 
+	// Required Minecraft classes
+	private static final Class<?> entityPlayerClass = Reflection.getClass("{nms}.EntityPlayer", "net.minecraft.server.level.EntityPlayer");
+	private static final Class<?> playerConnectionClass = Reflection.getClass("{nms}.PlayerConnection", "net.minecraft.server.network.PlayerConnection");
+	private static final Class<?> networkManagerClass = Reflection.getClass("{nms}.NetworkManager", "net.minecraft.network.NetworkManager");
+
 	// Used in order to lookup a channel
 	private static final MethodInvoker getPlayerHandle = Reflection.getMethod("{obc}.entity.CraftPlayer", "getHandle");
-	private static final FieldAccessor<Object> getConnection = Reflection.getField("{nms}.EntityPlayer", "playerConnection", Object.class);
-	private static final FieldAccessor<Object> getManager = Reflection.getField("{nms}.PlayerConnection", "networkManager", Object.class);
-	private static final FieldAccessor<Channel> getChannel = Reflection.getField("{nms}.NetworkManager", Channel.class, 0);
+	private static final FieldAccessor<?> getConnection = Reflection.getField(entityPlayerClass, null, playerConnectionClass);
+	private static final FieldAccessor<?> getManager = Reflection.getField(playerConnectionClass, null, networkManagerClass);
+	private static final FieldAccessor<Channel> getChannel = Reflection.getField(networkManagerClass, Channel.class, 0);
 
 	// Looking up ServerConnection
-	private static final Class<Object> minecraftServerClass = Reflection.getUntypedClass("{nms}.MinecraftServer");
-	private static final Class<Object> serverConnectionClass = Reflection.getUntypedClass("{nms}.ServerConnection");
+	private static final Class<Object> minecraftServerClass = Reflection.getUntypedClass("{nms}.MinecraftServer", "net.minecraft.server.MinecraftServer");
+	private static final Class<Object> serverConnectionClass = Reflection.getUntypedClass("{nms}.ServerConnection", "net.minecraft.server.network.ServerConnection");
 	private static final FieldAccessor<Object> getMinecraftServer = Reflection.getField("{obc}.CraftServer", minecraftServerClass, 0);
 	private static final FieldAccessor<Object> getServerConnection = Reflection.getField(minecraftServerClass, serverConnectionClass, 0);
-	private static final MethodInvoker getNetworkMarkers = Reflection.getTypedMethod(serverConnectionClass, null, List.class, serverConnectionClass);
 
 	// Packets we have to intercept
-	private static final Class<?> PACKET_LOGIN_IN_START = Reflection.getMinecraftClass("PacketLoginInStart");
+	private static final Class<?> PACKET_LOGIN_IN_START = Reflection.getClass("{nms}.PacketLoginInStart", "net.minecraft.network.protocol.login.PacketLoginInStart");
 	private static final FieldAccessor<GameProfile> getGameProfile = Reflection.getField(PACKET_LOGIN_IN_START, GameProfile.class, 0);
 
 	// Speedup channel lookup
@@ -199,8 +204,22 @@ public abstract class TinyProtocol {
 		Object serverConnection = getServerConnection.get(mcServer);
 		boolean looking = true;
 
+		try {
+			Field field = Reflection.getParameterizedField(serverConnectionClass, List.class, networkManagerClass);
+			field.setAccessible(true);
+
+			networkManagers = (List<Object>) field.get(serverConnection);
+		} catch (Exception ex) {
+			plugin.getLogger().info("Encountered an exception checking list fields" + ex);
+			MethodInvoker method = Reflection.getTypedMethod(serverConnectionClass, null, List.class, serverConnectionClass);
+
+			networkManagers = (List<Object>) method.invoke(null, serverConnection);
+		}
+
+		if (networkManagers == null) {
+			throw new IllegalArgumentException("Failed to obtain list of network managers");
+		}
 		// We need to synchronize against this list
-		networkManagers = (List<Object>) getNetworkMarkers.invoke(null, serverConnection);
 		createServerChannelHandler();
 
 		// Find the correct list, or implicitly throw an exception