MCCustomSkinLoader/Common/source/customskinloader/utils/MinecraftUtil.java

package customskinloader.utils;

import java.io.File;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.net.URL;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.mojang.authlib.GameProfile;
import net.minecraft.client.Minecraft;
import net.minecraft.client.multiplayer.ServerData;
import net.minecraft.client.renderer.texture.TextureManager;
import net.minecraft.client.resources.SkinManager;

/**
 * @author Alexander Xia
 * @since 13.6
 */
public class MinecraftUtil {
    public static File getMinecraftDataDir() {
        return Minecraft.getMinecraft().gameDir;
    }

    public static TextureManager getTextureManager() {
        return Minecraft.getMinecraft().getTextureManager();
    }

    public static SkinManager getSkinManager() {
        return Minecraft.getMinecraft().getSkinManager();
    }
    private static String minecraftMainVersion = null;

    public static String getMinecraftMainVersion() {
        //Check if cached version found
        if (minecraftMainVersion != null) {
            return minecraftMainVersion;
        }

        //version.json can be found in 1.14+
        URL versionFile = MinecraftUtil.class.getResource("/version.json");
        if (versionFile != null) {
            try (
                    InputStream is = versionFile.openStream();
                    InputStreamReader isr = new InputStreamReader(is)
            ) {
                JsonObject obj = new JsonParser().parse(isr).getAsJsonObject();
                minecraftMainVersion = obj.get("name").getAsString();
                return minecraftMainVersion;
            } catch (Exception ignored) {

            }
        }

        //RealmsSharedConstants.VERSION_STRING is available in 1.16-
        try {
            Class<?> realmsSharedConstants = Class.forName("net.minecraft.realms.RealmsSharedConstants");
            MethodHandle mh = MethodHandles.publicLookup().findStaticGetter(realmsSharedConstants, "VERSION_STRING", String.class);
            minecraftMainVersion = (String) mh.invoke();
            return minecraftMainVersion;
        } catch (Throwable ignored) {
        }

        //No version can be found
        return "unknown";
    }

    // (domain|ip)(:port)
    public static String getServerAddress() {
        ServerData data = Minecraft.getMinecraft().getCurrentServerData();
        if (data == null)//Single Player
            return null;
        return data.serverIP;
    }

    // ip:port
    public static String getStandardServerAddress() {
        return HttpUtil0.parseAddress(getServerAddress());
    }

    public static boolean isLanServer() {
        return HttpUtil0.isLanServer(getStandardServerAddress());
    }

    public static String getCredential(GameProfile profile) {
        return (profile == null || profile.hashCode() == 0) ? null :
                (profile.getId() == null ? profile.getName() : String.format("%s-%s", profile.getName(), profile.getId()));
    }
}