ActionBar.java

package tntrun.utils;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.bukkit.Bukkit;
import org.bukkit.entity.Player;

import tntrun.TNTRun;

public class ActionBar {
	private Class<?> nmsChatSerializer;
    private Class<?> nmsTitleAction;
    private Class<?> nmsPacketTitle;
    private Class<?> nmsPacketChat;
    private Class<?> nmsChatBaseComponent;
    private Object nmsIChatBaseComponent;
    private final String networkManager = "networkManager";
    private final String handle = "getHandle";
    private final String playerConnection = "playerConnection";
    private final String sendPacket = "sendPacket";
    
    private void loadClasses(){
        nmsIChatBaseComponent = getNMSClass("IChatBaseComponent");
        nmsPacketChat = getNMSClass("PacketPlayOutChat");

        nmsChatBaseComponent = getNMSClass("IChatBaseComponent");

        if (getVersion().contains("1_7")) {
            nmsChatSerializer = getNMSClass("ChatSerializer");
        } else if (getVersion().contains("1_8")) {
            if (getVersion().contains("R1")) {
                nmsChatSerializer = getNMSClass("ChatSerializer");
                nmsPacketTitle = getNMSClass("PacketPlayOutTitle");
                nmsTitleAction = getNMSClass("EnumTitleAction");
            } else if (getVersion().contains("R2") || getVersion().contains("R3")) {
                nmsChatSerializer = getNMSClass("IChatBaseComponent$ChatSerializer");
                nmsPacketTitle = getNMSClass("PacketPlayOutTitle");
                nmsTitleAction = getNMSClass("PacketPlayOutTitle$EnumTitleAction");
            }
        }else if(getVersion().contains("1_9")){
        	nmsChatSerializer = getNMSClass("IChatBaseComponent$ChatSerializer");
            nmsPacketTitle = getNMSClass("PacketPlayOutTitle");
            nmsTitleAction = getNMSClass("PacketPlayOutTitle$EnumTitleAction");
        }
    }

    public Class<?> getNMSChatSerializer() {
        return nmsChatSerializer;
    }

    public Class<?> getNMSIChatBaseComponent() {
        return nmsIChatBaseComponent.getClass();
    }

    public Class<?> getNMSPacketTitle() {
        return nmsPacketTitle;
    }

    public void sendActionBar(Player player, String message) {
    	loadClasses();
            try {
                Object handle = getMethod(player.getClass(), this.handle, new Class[0]).invoke(player, new Object[0]);
                Object playerConnection = getField(handle.getClass(), this.playerConnection).get(handle);
                Object serializedMessage = getMethod(this.nmsChatSerializer, "a", String.class).invoke(this.nmsChatSerializer, "{\"text\":\"" + message + "\"}");
                Object packet = null;
                if (getVersion().contains("1_7")) {
                    packet = this.nmsPacketChat.getConstructor(this.nmsChatBaseComponent, Integer.class).newInstance(serializedMessage, (int) 2);
                } else if (getVersion().contains("1_8") || getVersion().contains("1_9")) {
                    packet = this.nmsPacketChat.getConstructor(this.nmsChatBaseComponent, byte.class).newInstance(serializedMessage, (byte) 2);
                }

                getMethod(playerConnection.getClass(), this.sendPacket).invoke(playerConnection, packet);
            } catch (Exception localException) {
                localException.printStackTrace();
            }
        
    }
    
    private final Map<Class<?>, Class<?>> CORRESPONDING_TYPES = new HashMap<Class<?>, Class<?>>();
    
    private Class<?> getPrimitiveType(Class<?> clazz) {
		return CORRESPONDING_TYPES.containsKey(clazz) ? CORRESPONDING_TYPES
				.get(clazz) : clazz;
	}

	private Class<?>[] toPrimitiveTypeArray(Class<?>[] classes) {
		int a = classes != null ? classes.length : 0;
		Class<?>[] types = new Class<?>[a];
		for (int i = 0; i < a; i++)
			types[i] = getPrimitiveType(classes[i]);
		return types;
	}

	private boolean equalsTypeArray(Class<?>[] a, Class<?>[] o) {
		if (a.length != o.length)
			return false;
		for (int i = 0; i < a.length; i++)
			if (!a[i].equals(o[i]) && !a[i].isAssignableFrom(o[i]))
				return false;
		return true;
	}

	private Object getHandle(Object obj) {
		try {
			return getMethod("getHandle", obj.getClass()).invoke(obj);
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	private Method getMethod(String name, Class<?> clazz,
			Class<?>... paramTypes) {
		Class<?>[] t = toPrimitiveTypeArray(paramTypes);
		for (Method m : clazz.getMethods()) {
			Class<?>[] types = toPrimitiveTypeArray(m.getParameterTypes());
			if (m.getName().equals(name) && equalsTypeArray(types, t))
				return m;
		}
		return null;
	}

	public static String getVersion() {
		String name = Bukkit.getServer().getClass().getPackage().getName();
		String version = name.substring(name.lastIndexOf('.') + 1) + ".";
		return version;
	}

	private Class<?> getNMSClass(String className) {
		String fullName = "net.minecraft.server." + getVersion() + className;
		Class<?> clazz = null;
		try {
			clazz = Class.forName(fullName);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return clazz;
	}

	private Field getField(Class<?> clazz, String name) {
		try {
			Field field = clazz.getDeclaredField(name);
			field.setAccessible(true);
			return field;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	private Method getMethod(Class<?> clazz, String name, Class<?>... args) {
		for (Method m : clazz.getMethods())
			if (m.getName().equals(name)
					&& (args.length == 0 || ClassListEqual(args,
							m.getParameterTypes()))) {
				m.setAccessible(true);
				return m;
			}
		return null;
	}

	private boolean ClassListEqual(Class<?>[] l1, Class<?>[] l2) {
		boolean equal = true;
		if (l1.length != l2.length)
			return false;
		for (int i = 0; i < l1.length; i++)
			if (l1[i] != l2[i]) {
				equal = false;
				break;
			}
		return equal;
	}
}