[NOW WORKING] Using NMS and OBC Without Your Plugins Breaking [No Reflection Involved]

The Version Checker​

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WARNING: I HAVE BEEN NOTIFIED THAT IF YOU USE THIS CLASS, SOMETIMES YOU WILL GET A NoClassDefFoundException. SEE MY THREAD ABOUT CLASS MAPPING TO FIX THIS.​

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Introduction
Haven't you always wanted to tap into the secret sauce of Minecraft and use it to your own benefit without having your plugins break on every update? Sure you have! Luckily, we have reflection, which is a pain-in-the-butt and takes valuable time to learn, but that reflection isn't always reliable as well (for example, it broke all NMS-related plugins in the 1.7 update, even the ones with reflection due to class changes and re-structuring of internal code.) How do we use NMS and OBC without having our plugins break on every update, and without using reflection??? I have come up with a solution. No, it is not a 20 class library. It is not a modification to CraftBukkit. It is only a one class library, very short and sweet. When you see it you will say, "Why the didn't I think of that?"

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Usage​

This little class basically gets the current version of Bukkit that is on the server and sees if it equals another version. It returns a boolean, so it's only value is to use it in an if() or else() statement.​

Example:

PHP:

package bungeecookie.mineworks.api.nms;
 
import net.minecraft.server.v1_7_R1.EntityPlayer;
import net.minecraft.server.v1_7_R1.EnumClientCommand;
import net.minecraft.server.v1_7_R1.PacketPlayInClientCommand;
 
import org.bukkit.craftbukkit.v1_7_R1.entity.CraftPlayer;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.EventPriority;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.PlayerDeathEvent;
 
public class AutoRespawn implements Listener {
 
    @EventHandler(priority = EventPriority.HIGHEST)
    public void onRespawn(PlayerDeathEvent e){
 
        Player p = e.getEntity();
        if(VersionHandler.is1_7_2()){
            PacketPlayInClientCommand in = new PacketPlayInClientCommand(EnumClientCommand.PERFORM_RESPAWN); // Gets the packet class
            EntityPlayer cPlayer = ((CraftPlayer)p).getHandle(); // Gets the EntityPlayer class
            cPlayer.playerConnection.a(in); // Handles the rest of it
        }
 
        else if(VersionHandler.is1_6_4()){
            try {
                Object nmsPlayer = p.getClass().getMethod("getHandle").invoke(p);
                Object packet = Class.forName(nmsPlayer.getClass().getPackage().getName() + ".Packet205ClientCommand").newInstance();
                packet.getClass().getField("a").set(packet, 1);
                Object con = nmsPlayer.getClass().getField("playerConnection").get(nmsPlayer);
                con.getClass().getMethod("a", packet.getClass()).invoke(con, packet);
            } catch (Throwable ex) {
                ex.printStackTrace();
            }
        }
    }
 
}

Conclusion:

To end this awesome resource, I am going to post the code. If you need any help, suggestions, or ideas, please tag me using BungeeTheCookie. If you enjoyed it, please take 2 seconds of your time and leave a like or post a comment, just to show that people enjoyed it.​

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PHP:

import org.bukkit.Bukkit;
 
public class VersionHandler {
 
    public static boolean is1_2_5(){
        if(Bukkit.getVersion().contains("1.2.5")){
            return true;
        }
        return false;
    }
    public static boolean is1_3_2(){
        if(Bukkit.getVersion().contains("1.3.2")){
            return true;
        }
        return false;
    }
    public static boolean is1_4_7(){
        if(Bukkit.getVersion().contains("1.4.7")){
            return true;
        }
        return false;
    }
    public static boolean is1_5_2(){
        if(Bukkit.getVersion().contains("1.5.2")){
            return true;
        }
        return false;
    }
    public static boolean is1_6_2(){
        if(Bukkit.getVersion().contains("1.6.2")){
            return true;
        }
        return false;
    }
    public static boolean is1_6_4(){
        if(Bukkit.getVersion().contains("1.6.4")){
            return true;
        }
        return false;
    }
 
    public static boolean is1_7_2(){
        if(Bukkit.getVersion().contains("1.7") && Bukkit.getServer().getClass().getPackage().getName().contains("R1")){
            return true;
        }
        return false;
    }
 
    public static boolean is1_7_9(){
        if(Bukkit.getVersion().contains("1.7") && Bukkit.getServer().getClass().getPackage().getName().contains("R3")){
            return true;
        }
        return false;
    }
 
    public static boolean matchesVersion(String s){
        if(Bukkit.getVersion().contains(s) || Bukkit.getServer().getClass().getPackage().getName().contains(s)){
            return true;
        }
        return false;
    }
}


Reserved.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

BungeeTheCookie
Well, uh, I kinda overestimated the meaning of "short/sweet"

 

Could I just ask - does that code automatically respawn players?

 

Yes.

 

You're amazing. =P

 

Code:

public static String getPackageVersion() {
        try {
            Class<?> serverClass = plugin.getServer().getClass();
            if (serverClass.getName().contains("CraftServer")) {
                String packageName = serverClass.getPackage().getName();
                int dotIndex = packageName.lastIndexOf('.');
                if (dotIndex != -1) {
                    return packageName.substring(dotIndex + 1);
                }
            }
        } catch (NoClassDefFoundError e) {
            plugin.getLogger().severe(
                    "You seem to have a pretty modified version of CraftBukkit. " +
                            "This will cause the plugin to fallback to the default implementation, and may not function properly.");
            if(debug)
                e.printStackTrace();
        }
        return null;
    }

I personally like using this method instead. It returns the package name, which you can then use in reflection to get nms/cb classes, so its a bit more helpful

 

Cool! I designed this class so I can avoid using reflection, so I just made a simple is_VERSION() method for people who don't use reflection. But that works too!

KingFaris11
Thanks! I try my best.

For those of you who enjoy the old days of Redpower, Hexxit, Tekkit Classic, or other outdated modpacks (I cannot find any other reason why you would want to play on 1.2.5), I have added support from 1.2.5 up to 1.7.8! I also added a matchesVersion boolean so you can match the version you want to another.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

I compressed your VersionHandler to this

 

Thanks! I do enjoy me some HasteBin.

 

Instead of EqualsIgnoreCase, many times Bukkit.getVersion() returns something like git-Bukkit-1.7.2-R0.3-b3020jnks (MC: 1.7.2). A better method would be Bukkit.getVersion().contains("1.7.2")!

 

This still breaks when a new version appears..

 

TigerHix Ultimate_n00b
Fixed.

ccrama
Thanks for pointing that out! I have hopefully fixed it.

 

BungeeTheCookie Nope, I mean if someday Bukkit is on 1.8.2 and my plugin which uses your VersionHandler only handles conditions under 1.7.2 and 1.7.8, my plugin still breaks.

 

TigerHix
This plugin is intended to allow plugins to be backwards compatible and avoiding using reflection. You can always uses matchesVersion

 

without having our plugins break on every update
+
import net.minecraft.server.v1_7_R1.PacketPlayInClientCommand;

you tutorial is invalid.

 

Have you even read it? Or did you just simply look at the code? This tutorial prevents plugins from breaking because it uses a boolean that can be used in an if statement..

 

You still don't understand. When Bukkit has a update, server owner updates, the Bukkit version changes, and any plugin using this VersionHandler will be f-ed up.. Instead if we use reflection, at least there's a chance that internal classes are not changed unlike 1.7 huge update, there's a change plugins still run well. So I don't see any reasons that using your class can "use nms and obc without plugins breaking".

 

This ^

 

Actually, I completely understand what you are talking about. I am actually very familiar with how NMS and OBC break your plugins. I designed this class to allow plugin devs to make plugins be backwards compatible with other versions. Here is an example. If a server owner designs a plugin to use with 1.7.9 which uses NMS, and a guy wants to use it with 1.6.4 or 1.5.2 (say you are using a multi-version Bungeecord server and are using a backend) you will just put in the if() statement so your plugin can handle 2 - 10 versions.

 

Even though I am not familiar with NMS... I see an error with the is1_7_5 method..

It is checking if it contains 1.7.2, not 1.7.5

 

Fixed.

 

run your "super tutorial code" on 162 and post stacktrace, its not ok to post random tutorials about things you not understand.

 

What?

 

BungeeTheCookie In your tutorial code you are importing 1.7.x code, so your class wouldn't work on any other version because it would throw a ClassDefNotFoundException. Just change everything to reflection like you did if the version is 1.6.

Edit: it would be NoClassDefFoundException ofcourse.

 

You might also be able to do something like this (don't import, just type out the whole path for every version), although I am not sure if this does work:

Code:java

net.minecraft.server.v1_7_R1.PacketPlayInClientCommand in = new net.minecraft.server.v1_7_R1.PacketPlayInClientCommand(net.minecraft.server.v1_7_R1.EnumClientCommand.PERFORM_RESPAWN);

 

CaptainBern Haha good point.

 

You use an if else statement. If a version is 1.7.2, then do 1.7.2 NMS, else use 1.6.4 NMS else do nothing

You could do that too

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

BungeeTheCookie bigteddy98 Tried that a few days ago, server kept spitting could not find class, and was trying to call classes based on other versions not specified in the if statement.

Also, I highly recommend throwing in revision support, as 1.7.2 has three different revisions (for example), and each one has different NMS paths.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

aah okay, great to know.