Util [Class] Overcomming the Action Bar problem.

Hello bukkit comunity.
In recent versions of Bukkit alternatives (1.8.3+) trying to use the Version independed Action bar setting code doesnt quite work, and that is because the ChatSerialiser class throws a ClassNotFoundException when looked up by Class.forName(String param);

So i made a class that overcomes that and it is still version independed! (Warning, if a class from the NMS packages changes, it will break.)

The class can be found here:

Code:

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

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

/**
* @author fillpant AKA mine-care
* <h1>Info:</h1> This is a utility class to overcome the
* problem that occurs in the latest versions (1.8.3+) where
* ChatSerialiser class cannot be found.
*/
public class ActionBarUtil {
    private static final String BV = Bukkit.getServer().getClass().getPackage().getName().substring(23);
    private static boolean initialised = false;
    private static Constructor<?> chatSer;
    private static Constructor<?> packetChat;
    private static Method getPlayerHandle;
    private static Field playerConnection;
    private static Method sendPacket;

    static {
        try {
            chatSer = ReflectionUtils.getConstructor(
                    Class.forName("net.minecraft.server." + BV
                            + ".ChatComponentText"), String.class);

            packetChat = Class.forName(
                    "net.minecraft.server." + BV + ".PacketPlayOutChat")
                    .getConstructor(
                            Class.forName("net.minecraft.server." + BV
                                    + ".IChatBaseComponent"), byte.class);
            getPlayerHandle = Class.forName(
                    "org.bukkit.craftbukkit." + BV + ".entity.CraftPlayer")
                    .getDeclaredMethod("getHandle");
            playerConnection = Class.forName(
                    "net.minecraft.server." + BV + ".EntityPlayer")
                    .getDeclaredField("playerConnection");
            sendPacket = Class.forName(
                    "net.minecraft.server." + BV + ".PlayerConnection")
                    .getDeclaredMethod(
                            "sendPacket",
                            Class.forName("net.minecraft.server." + BV
                                    + ".Packet"));
            initialised = true;
        } catch (ReflectiveOperationException e) {
            e.printStackTrace();
            Bukkit.getServer()
                    .getLogger()
                    .warning(
                            "Cannot initialise Action Bar Utils (Blame fillpant)");
            initialised = false;
        }
    }

    /**
     * This method checks if the ActionBarUtil has been initialised properly
     * @return returns a boolean indicating initialization.
     */
    public static boolean isInitialised(){
        return initialised;
    }
   
    /**
     * This method sends an ActionBar message to a player, ChatColor works as well.
     * @param message The message to be sent to the player(s).
     * @param p The player(s) to receive the ActionBar message.
     * @return Returns a boolean indicating if the method ececution was successfull.
     * <br><b>NOTE: If anything goes wrong the utility will automatically
     *  stop working to prevent massive ammouts of errors showing up in console.</b>
     */
    public static boolean sendActionBar(String message, Player... p) {
        if (!initialised) return false;
        try {
            Object o = chatSer.newInstance(message);
            Object packet = packetChat.newInstance(o, (byte) 2);
            sendPacket(packet, p);
        } catch (ReflectiveOperationException e) {
            e.printStackTrace();
            initialised = false;
        }
        return initialised;
    }

    /**
      * IGNORE THIS!
      */
    private static void sendPacket(Object packet, Player... pl)
            throws ReflectiveOperationException {
        for (Player p : pl) {
            Object entityplayer = getPlayerHandle.invoke(p);
            Object PlayerConnection = playerConnection.get(entityplayer);
            sendPacket.invoke(PlayerConnection, packet);
        }
    }
}

Example usage:

Code:

Player p = ...;
ActionBarUtil.sendActionBar(ChatColor.GOLD+"This is an action bar "+ChatColor.GREEN+" message!",p);

Alternatively, you can also use this method with varargs,

Code:

Player p  = ...;
Player o  = ...;
ActionBarUtil.sendActionBar(ChatColor.GOLD+"This is an action bar "+ChatColor.GREEN+" message!",p,o);

For any questions you may have let me know!

 

I love how your tutorials are getting better and better!
+1(00)

 

@ChipDev Thanks!

 

@mine-care
I don't wanna ruin your moment but you can actually retrieve the class using net.minecraft.server.<version>.IChatBaseComponent$ChatSerializer ;p

 

@megamichiel to be Honnest I noticed it has become a nested class in between versions so I decided not to use it for my project since it is used by mojang a lot and they obviously can change it again. On the other hand, chatcomponenttect as you can see from early versions doesn't seem to change packages or names. So I thought I would go with it.
You are not ruining the moment, instead you are saying something very correct! I should have mentioned.

I based this thread to the latest reports of "ClassNotFoundException" with ChatSerialiser to get the attention of people, I could name it "Version independed action bar message" but it wouldn't be catchy to the ones tying to fix the CNFE :/

Thanks for your post

 

@mine-care This is why you don't use reflection and use abstraction instead.

 

@teej107 I agree with you but abstraction has to be updated for every single version of CB and the snippet using reflection only has to be updated once a change is made and it breaks.
Plus as many people would say, i am a reflection nerd

 

@mine-care
Ah, I fully understand .