minecraft-kajetans-core-mod/src/main/resources/class_transformer/test.js

var transformerName = "Dedicated Server Transformer";
var ASMAPI = Java.type('net.minecraftforge.coremod.api.ASMAPI');
var Opcodes = Java.type('org.objectweb.asm.Opcodes');
var VarInsnNode = Java.type("org.objectweb.asm.tree.VarInsnNode");
var MethodInsnNode = Java.type("org.objectweb.asm.tree.MethodInsnNode");
var LineNumberNode = Java.type("org.objectweb.asm.tree.LineNumberNode");

function initializeCoreMod() {
    return {
        transformerName: {
            'target': {
                'type': 'CLASS',
                'name': 'net.minecraft.server.dedicated.DedicatedServer'
            },
            'transformer': function (classNode) {
                var methods = classNode.methods;

                var targetMethodName = ASMAPI.mapMethod("func_71197_b"); // init
                var targetMethodDesc = "()Z";

                for (var i in methods)
                {
                    var method = methods[i];

                    print(method.name + " " + method.desc);
                    if (method.name.equals(targetMethodName) && method.desc.equals(targetMethodDesc))
                    {
                        transform(method);
                        break;
                    }
                }
                return classNode;
            }
        }
    };
}

function transform(method)
{
    print("Match found " + method.name + " " + method.desc);
    var instrList = method.instructions;
    
    /*instrList.remove(instrList.get(2));
    instrList.insert(instrList.get(1), new VarInsnNode(Opcodes.ALOAD, 0));
    instrList.insert(instrList.get(2), new MethodInsnNode(Opcodes.INVOKESTATIC, "me/kcm/events/Hooks", 
        "onGetTabListDisplayName", "(Lnet/minecraft/entity/player/EntityPlayerMP;)Lnet/minecraft/util/text/ITextComponent;", false));*/
    
    for(var i = 0; i < instrList.size(); ++i) 
    {
        var instr = instrList.get(i);
        if(instr.getOpcode() == 183 && instr instanceof MethodInsnNode && instr.owner == "net/minecraft/server/dedicated/DedicatedPlayerList")
        {
            print("_________________________________________");
            for(var j = -10; j < 10; j++)
            {
                printInstr(instrList.get(i + j));
            }
                           
            instrList.remove(instrList.get(i - 4));
            instrList.remove(instrList.get(i - 4));
            instrList.remove(instrList.get(i - 4));
            instrList.remove(instrList.get(i - 4));
            instrList.remove(instrList.get(i - 4));
            instrList.remove(instrList.get(i - 4));
            
            instrList.insert(instrList.get(i - 5), new VarInsnNode(Opcodes.ALOAD, 0));
            //instrList.insert(instrList.get(i - 4), new MethodInsnNode(Opcodes.INVOKESTATIC, "me/kcm/events/Hooks", 
            //    "newPlayerList", "(Lnet/minecraft/server/dedicated/DedicatedServer;)Lnet/minecraft/server/dedicated/DedicatedPlayerList;", false));
            //instrList.insert(instrList.get(i - 3), new MethodInsnNode(Opcodes.INVOKESTATIC, "me/kcm/events/Hooks", 
            //    "newPlayerList", "()Lnet/minecraft/server/dedicated/DedicatedPlayerList;", false));
            instrList.insert(instrList.get(i - 4), new MethodInsnNode(Opcodes.INVOKESTATIC, "me/kcm/events/Hooks", 
                "setPlayerList", "(Lnet/minecraft/server/dedicated/DedicatedServer;)V", false));
                
            print("_________________________________________");
            for(var j = -10; j < 10; j++)
            {
                printInstr(instrList.get(i + j));
            }
            break;
        }
    }
}

function printInstr(instr)
{
    if(instr.getOpcode() == -1)
    {
        return;
    }
    var out = "> ";
    out += instr.getOpcode();
    out += "_";
    out += instr.getType();
    
    if(instr instanceof VarInsnNode)
    {
        out += " Var: " + instr.var;
    }
    else if(instr instanceof MethodInsnNode)
    {
        out += " " + instr.owner + "." + instr.name + ":" + instr.desc;
    }
    else if(instr instanceof FieldInsnNode)
    {
        out += " " + instr.owner + "." + instr.name + ":" + instr.desc;
    }
    //out += " " + instr;
    print(out);
}