Re-add 1.7 support via extra-poor effort classes which work just fine and don't look too bad (ps: there is also one non-maven dependency (not added) which you'll need to extract and add to the cloud lib k thanks bye)

.gitignore

@@ -32,3 +32,7 @@
 *~
 
 dependency-reduced-pom.xml
+
+# Lib
+/lib
+/lib/1.7.10.jar

README.md

@@ -1,7 +1,7 @@
 Bukkit-Connect [![Jenkins](https://img.shields.io/jenkins/s/http/ci.lilypadmc.org/Bukkit-Connect.svg?maxAge=2592000?style=flat-square)](http://ci.lilypadmc.org/job/Bukkit-Connect)
 ===========
 
-This version of Bukkit-Connect supports Spigot 1.8 through 1.12
+This version of Bukkit-Connect supports Spigot 1.7 through 1.15
 
 Compilation
 -----------
@@ -10,3 +10,4 @@ We use maven to handle our dependencies.
 
 * Install [Maven 3](http://maven.apache.org/download.html)
 * Clone this repo and: `mvn clean install`
+* Add any 1.7.10 CraftBukkit jar in /lib/1.7.10.jar. This is mandatory to not get DMCAed.

pom.xml

@@ -47,6 +47,18 @@
       <artifactId>gson</artifactId>
       <version>2.2.4</version>
     </dependency>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+      <version>28.2-jre</version>
+    </dependency>
+    <dependency>
+      <groupId>org.spigotmc</groupId>
+      <artifactId>spigot-api2</artifactId>
+      <version>1.7.10-SNAPSHOT</version>
+      <scope>system</scope>
+      <systemPath>${project.basedir}/lib/1.7.10.jar</systemPath>
+    </dependency>
     <dependency>
       <groupId>org.spigotmc</groupId>
       <artifactId>spigot-api</artifactId>

src/main/java/lilypad/bukkit/connect/ConnectPlugin.java

@@ -2,11 +2,15 @@
 
 import lilypad.bukkit.connect.hooks.SpigotHook;
 import lilypad.bukkit.connect.injector.HandlerListInjector;
-import lilypad.bukkit.connect.injector.NettyInjector;
+import lilypad.bukkit.connect.injector.injector.INettyInjector;
+import lilypad.bukkit.connect.injector.injector.NettyInjector;
 import lilypad.bukkit.connect.injector.OfflineInjector;
+import lilypad.bukkit.connect.injector.PacketInjector;
+import lilypad.bukkit.connect.injector.injector.NettyInjectorLegacy;
 import lilypad.bukkit.connect.login.LoginListener;
-import lilypad.bukkit.connect.login.LoginNettyInjectHandler;
+import lilypad.bukkit.connect.login.inject.LoginNettyInjectHandler;
 import lilypad.bukkit.connect.login.LoginPayloadCache;
+import lilypad.bukkit.connect.login.inject.LoginNettyInjectHandlerLegacy;
 import lilypad.bukkit.connect.protocol.*;
 import lilypad.bukkit.connect.util.ReflectionUtils;
 import lilypad.client.connect.api.Connect;
@@ -28,6 +32,8 @@ public class ConnectPlugin extends JavaPlugin {
 	private String securityKey;
 	private int commonPort;
 	private static IProtocol protocol;
+	private INettyInjector nettyInjector;
+	private boolean isLegacy = false;
 
 	@Override
 	public void onLoad() {
@@ -39,7 +45,12 @@ public void onLoad() {
 	@Override
 	public void onEnable() {
 		String version = super.getServer().getClass().getPackage().getName().replace(".",  ",").split(",")[3];
+		isLegacy = version.equalsIgnoreCase("v1_7_R4");
+		nettyInjector = isLegacy ? new NettyInjectorLegacy() : new NettyInjector();
 		switch (version) {
+		case "v1_7_R4":
+			protocol = new Protocol1_7_R4();
+			break;
 		case "v1_8_R1":
 			protocol = new Protocol1_8_R1();
 			break;
@@ -76,11 +87,19 @@ public void onEnable() {
 		try {
 			// Modify handshake packet max string size
 			// -- as of 1.8 I do not believe this is necessary anymore
-			/*if (!protocol.getGeneralVersion().equals("1.10")) {
+			/*
+			if (!protocol.getGeneralVersion().equals("1.10")) {
 				PacketInjector.injectStringMaxSize(super.getServer(), "handshaking", 0x00, 65535);
 			}*/
 			// Handle LilyPad handshake packet
-			commonPort = NettyInjector.injectAndFindPort(super.getServer(), new LoginNettyInjectHandler(this, payloadCache));
+
+			// Little fix for adding Legacy support :>
+
+			commonPort = nettyInjector.injectAndFindPort(super.getServer(),
+					(isLegacy ? new LoginNettyInjectHandlerLegacy(this, payloadCache)
+							:  new LoginNettyInjectHandler(this, payloadCache)));
+
+
 			// If we are in online-mode
 			if (super.getServer().getOnlineMode()) {
 				// Prioritize our events

src/main/java/lilypad/bukkit/connect/injector/HandlerListInjector.java

@@ -1,6 +1,7 @@
 package lilypad.bukkit.connect.injector;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.EnumMap;
 import java.util.List;
 

src/main/java/lilypad/bukkit/connect/injector/NettyDecoderHandler.java → src/main/java/lilypad/bukkit/connect/injector/decoder/NettyDecoderHandler.java

@@ -1,13 +1,11 @@
-package lilypad.bukkit.connect.injector;
+package lilypad.bukkit.connect.injector.decoder;
 
-import io.netty.buffer.ByteBuf;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.codec.MessageToMessageDecoder;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandler;
+
 
-import java.lang.reflect.Method;
-import java.util.Iterator;
 import java.util.List;
-import java.util.ArrayList;
 
 public class NettyDecoderHandler extends MessageToMessageDecoder<Object> {
 

src/main/java/lilypad/bukkit/connect/injector/decoder/NettyDecoderHandlerLegacy.java

@@ -0,0 +1,33 @@
+package lilypad.bukkit.connect.injector.decoder;
+
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandlerLegacy;
+import net.minecraft.util.io.netty.channel.ChannelHandlerContext;
+import net.minecraft.util.io.netty.handler.codec.MessageToMessageDecoder;
+
+import java.util.List;
+
+public class NettyDecoderHandlerLegacy extends MessageToMessageDecoder<Object> {
+
+	private NettyInjectHandlerLegacy handler;
+	private boolean enabled = true;
+
+	public NettyDecoderHandlerLegacy(NettyInjectHandlerLegacy handler) throws Exception {
+		this.handler = handler;
+	}
+
+	@Override
+	protected void decode(ChannelHandlerContext context, Object packet, List<Object> out) throws Exception {
+		if (this.enabled && this.handler.isEnabled()) {
+			this.handler.packetReceived(this, context, packet);
+		}
+		out.add(packet);
+		if (!this.enabled) {
+			context.pipeline().remove("lilypad_decoder");
+		}
+	}
+
+	public void disable() {
+		this.enabled = false;
+	}
+
+}

src/main/java/lilypad/bukkit/connect/injector/handler/NettyInjectHandler.java

@@ -0,0 +1,12 @@
+package lilypad.bukkit.connect.injector.handler;
+
+import io.netty.channel.ChannelHandlerContext;
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandler;
+
+public interface NettyInjectHandler {
+
+	void packetReceived(NettyDecoderHandler handler, ChannelHandlerContext context, Object object) throws Exception;
+
+	boolean isEnabled();
+
+}

src/main/java/lilypad/bukkit/connect/injector/handler/NettyInjectHandlerLegacy.java

@@ -0,0 +1,13 @@
+package lilypad.bukkit.connect.injector.handler;
+
+
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandlerLegacy;
+import net.minecraft.util.io.netty.channel.ChannelHandlerContext;
+
+public interface NettyInjectHandlerLegacy {
+
+	void packetReceived(NettyDecoderHandlerLegacy handler, ChannelHandlerContext context, Object object) throws Exception;
+
+	boolean isEnabled();
+
+}

src/main/java/lilypad/bukkit/connect/injector/NettyChannelInitializer.java → src/main/java/lilypad/bukkit/connect/injector/initializer/NettyChannelInitializer.java

@@ -1,11 +1,13 @@
-package lilypad.bukkit.connect.injector;
-
-import org.bukkit.Bukkit;
+package lilypad.bukkit.connect.injector.initializer;
 
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.socket.SocketChannel;
-import io.netty.handler.codec.ByteToMessageDecoder;
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandler;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandler;
+import org.bukkit.Bukkit;
+
+
 
 import java.lang.reflect.Method;
 
@@ -21,10 +23,9 @@ public NettyChannelInitializer(NettyInjectHandler handler, ChannelInitializer<So
 		this.oldChildHandlerMethod = this.oldChildHandler.getClass().getDeclaredMethod("initChannel", Channel.class);
 		this.oldChildHandlerMethod.setAccessible(true);
 	}
-	
+
 	@Override
 	protected void initChannel(SocketChannel channel) throws Exception {
-		// Call Old InitChannel
 		this.oldChildHandlerMethod.invoke(this.oldChildHandler, channel);
 		// Add Handlers
 		if (this.handler.isEnabled()) {
@@ -34,5 +35,4 @@ protected void initChannel(SocketChannel channel) throws Exception {
 			channel.pipeline().addAfter("decoder", "lilypad_decoder", new NettyDecoderHandler(this.handler));
 		}
 	}
-
 }

src/main/java/lilypad/bukkit/connect/injector/initializer/NettyChannelInitializerLegacy.java

@@ -0,0 +1,38 @@
+package lilypad.bukkit.connect.injector.initializer;
+
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandlerLegacy;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandlerLegacy;
+import net.minecraft.util.io.netty.channel.Channel;
+import net.minecraft.util.io.netty.channel.ChannelInitializer;
+import net.minecraft.util.io.netty.channel.socket.SocketChannel;
+import org.bukkit.Bukkit;
+
+import java.lang.reflect.Method;
+
+public class NettyChannelInitializerLegacy extends ChannelInitializer<SocketChannel> {
+
+	private NettyInjectHandlerLegacy handler;
+	private ChannelInitializer<SocketChannel> oldChildHandler;
+	private Method oldChildHandlerMethod;
+
+	public NettyChannelInitializerLegacy(NettyInjectHandlerLegacy handler, ChannelInitializer<SocketChannel> oldChildHandler) throws Exception {
+		this.handler = handler;
+		this.oldChildHandler = oldChildHandler;
+		this.oldChildHandlerMethod = this.oldChildHandler.getClass().getDeclaredMethod("initChannel", Channel.class);
+		this.oldChildHandlerMethod.setAccessible(true);
+	}
+
+	@Override
+	protected void initChannel(SocketChannel channel) throws Exception {
+		// Call Old InitChannel
+		this.oldChildHandlerMethod.invoke(this.oldChildHandler, channel);
+		// Add Handlers
+		if (this.handler.isEnabled()) {
+			if (channel.pipeline().names().contains("legacy_query") && Bukkit.getServer().getPluginManager().getPlugin("ProtocolSupport") == null) {
+				channel.pipeline().remove("legacy_query");
+			}
+			channel.pipeline().addAfter("decoder", "lilypad_decoder", new NettyDecoderHandlerLegacy(this.handler));
+		}
+	}
+
+}

src/main/java/lilypad/bukkit/connect/injector/injector/INettyInjector.java

@@ -0,0 +1,9 @@
+package lilypad.bukkit.connect.injector.injector;
+
+import org.bukkit.Server;
+
+
+public interface INettyInjector {
+
+    int injectAndFindPort(Server server, Object handler) throws Exception;
+}

src/main/java/lilypad/bukkit/connect/injector/NettyInjector.java → src/main/java/lilypad/bukkit/connect/injector/injector/NettyInjector.java

@@ -1,4 +1,4 @@
-package lilypad.bukkit.connect.injector;
+package lilypad.bukkit.connect.injector.injector;
 
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
@@ -11,14 +11,16 @@
 import java.util.List;
 
 import lilypad.bukkit.connect.ConnectPlugin;
+import lilypad.bukkit.connect.injector.initializer.NettyChannelInitializer;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandler;
 import lilypad.bukkit.connect.util.ReflectionUtils;
 
 import org.bukkit.Server;
 
-public class NettyInjector {
+public class NettyInjector implements INettyInjector {
 
 	@SuppressWarnings("unchecked")
-	public static int injectAndFindPort(Server server, NettyInjectHandler handler) throws Exception {
+	public int injectAndFindPort(Server server, Object handler) throws Exception {
 		Method serverGetHandle = server.getClass().getDeclaredMethod("getServer");
 		Object minecraftServer = serverGetHandle.invoke(server);
 		// Get Server Connection
@@ -43,7 +45,7 @@ public static int injectAndFindPort(Server server, NettyInjectHandler handler) t
 			// Get Old ChildHandler
 			ChannelInitializer<SocketChannel> oldChildHandler = ReflectionUtils.getPrivateField(serverBootstrapAcceptor.getClass(), serverBootstrapAcceptor, ChannelInitializer.class, "childHandler");
 			// Set New ChildHandler
-			ReflectionUtils.setFinalField(serverBootstrapAcceptor.getClass(), serverBootstrapAcceptor, "childHandler", new NettyChannelInitializer(handler, oldChildHandler));
+			ReflectionUtils.setFinalField(serverBootstrapAcceptor.getClass(), serverBootstrapAcceptor, "childHandler", new NettyChannelInitializer((NettyInjectHandler) handler, oldChildHandler));
 			// Update Common Port
 			commonPort = ((InetSocketAddress) channelFuture.channel().localAddress()).getPort();
 		}

src/main/java/lilypad/bukkit/connect/injector/injector/NettyInjectorLegacy.java

@@ -0,0 +1,58 @@
+package lilypad.bukkit.connect.injector.injector;
+
+import lilypad.bukkit.connect.ConnectPlugin;
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandler;
+import lilypad.bukkit.connect.injector.decoder.NettyDecoderHandlerLegacy;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandlerLegacy;
+import lilypad.bukkit.connect.injector.initializer.NettyChannelInitializer;
+import lilypad.bukkit.connect.injector.handler.NettyInjectHandler;
+import lilypad.bukkit.connect.injector.initializer.NettyChannelInitializerLegacy;
+import lilypad.bukkit.connect.login.inject.LoginNettyInjectHandlerLegacy;
+import lilypad.bukkit.connect.util.ReflectionUtils;
+import net.minecraft.util.io.netty.channel.ChannelFuture;
+import net.minecraft.util.io.netty.channel.ChannelHandler;
+import net.minecraft.util.io.netty.channel.ChannelInitializer;
+import net.minecraft.util.io.netty.channel.ChannelPipeline;
+import net.minecraft.util.io.netty.channel.socket.SocketChannel;
+import org.bukkit.Server;
+
+import java.lang.reflect.Method;
+import java.net.InetSocketAddress;
+import java.util.List;
+
+public class NettyInjectorLegacy implements INettyInjector {
+
+	@SuppressWarnings("unchecked")
+	public int injectAndFindPort(Server server, Object handler) throws Exception {
+		Method serverGetHandle = server.getClass().getDeclaredMethod("getServer");
+		Object minecraftServer = serverGetHandle.invoke(server);
+		// Get Server Connection
+		Method serverConnectionMethod = null;
+		for(Method method : minecraftServer.getClass().getSuperclass().getDeclaredMethods()) {
+			if(!method.getReturnType().getSimpleName().equals("ServerConnection")) {
+				continue;
+			}
+			serverConnectionMethod = method;
+			break;
+		}
+		Object serverConnection = serverConnectionMethod.invoke(minecraftServer);
+		// Get ChannelFuture List // TODO find the field dynamically
+		List<ChannelFuture> channelFutureList = ReflectionUtils.getPrivateField(serverConnection.getClass(), serverConnection, List.class, ConnectPlugin.getProtocol().getNettyInjectorChannelFutureList());
+		// Iterate ChannelFutures
+		int commonPort = 0;
+		for(ChannelFuture channelFuture : channelFutureList) {
+			// Get ChannelPipeline
+			ChannelPipeline channelPipeline = channelFuture.channel().pipeline();
+			// Get ServerBootstrapAcceptor
+			ChannelHandler serverBootstrapAcceptor = channelPipeline.last();
+			// Get Old ChildHandler
+			ChannelInitializer<SocketChannel> oldChildHandler = ReflectionUtils.getPrivateField(serverBootstrapAcceptor.getClass(), serverBootstrapAcceptor, ChannelInitializer.class, "childHandler");
+			// Set New ChildHandler
+			ReflectionUtils.setFinalField(serverBootstrapAcceptor.getClass(), serverBootstrapAcceptor, "childHandler", new NettyChannelInitializerLegacy((LoginNettyInjectHandlerLegacy) handler, oldChildHandler));
+			// Update Common Port
+			commonPort = ((InetSocketAddress) channelFuture.channel().localAddress()).getPort();
+		}
+		return commonPort;
+	}
+
+}

src/main/java/lilypad/bukkit/connect/login/LoginPayloadCache.java

@@ -1,14 +1,17 @@
 package lilypad.bukkit.connect.login;
 
-import java.util.concurrent.TimeUnit;
+
 
 import com.google.common.cache.Cache;
 import com.google.common.cache.CacheBuilder;
 
+import java.util.concurrent.TimeUnit;
+
+
 public class LoginPayloadCache {
 
 	private Cache<String, LoginPayload> payloads = CacheBuilder.newBuilder().expireAfterWrite(30, TimeUnit.SECONDS).build();
-	
+
 	public void submit(LoginPayload payload) {
 		this.payloads.put(payload.getName(), payload);
 	}