Language Downloader

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.nio.file.Path;
import java.nio.file.Paths;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.stream.JsonReader;
//To get the default english language file you have to decompile the minecraft.jar then go to assets>Minecraft>lang>en_us.json
public class Downloader {
    String ver;
    String output;
    Path assets;
    JsonObject obj;

    public void download(String version, String outputLocation, String minecraftFolder) {
        assets = Paths.get(minecraftFolder).resolve("assets");
        Path indexes = assets.resolve("indexes");


        ver = version;
        output = outputLocation;

        obj = retrieveJson(indexes.resolve(version + ".json").toAbsolutePath().toString());

        obj = obj.get("objects").getAsJsonObject();
        obj.keySet().stream().filter(key -> {
            return key.startsWith("minecraft/lang/");
        }).forEach(lang -> {
            retreivePack(obj.get(lang).getAsJsonObject().get("hash").getAsString());
        });

    }

    private void retreivePack(String key) {
        String folder = key.substring(0, 2);
        JsonObject jo = retrieveJson(
                assets.resolve("objects").resolve(folder).resolve(key).toAbsolutePath().toString());
        String code = jo.get("language.code").getAsString();
        // jo = filterJson(jo);
        downloadPack(jo, code);
    }

    private void downloadPack(JsonObject jo, String key) {
        try {
            File file = new File(File.separator + output + File.separator + key + ".json");
            File filePath = new File(File.separator + output);
            filePath.mkdirs();
            if (!file.exists()) {
                file.createNewFile();
            }
            FileWriter fileWriter = new FileWriter(file);
            fileWriter.write(jo.toString());
            fileWriter.flush();
            fileWriter.close();
            System.out.println("wrote to " + file.getAbsolutePath());

        } catch (Exception e) {

        }
    }

    private JsonObject filterJson(JsonObject jo) {
        JsonObject items = new JsonObject();

        jo.keySet().stream().sorted().forEach(key -> {
            if ((key.toString().startsWith("block.minecraft.") || key.toString().startsWith("item.minecraft."))) {
                items.add(key, jo.get(key));
            }
        });
        return items;

    }

    private JsonObject retrieveJson(String loc) {
        try {

            File file = new File(loc);
            Object obj = JsonParser.parseReader(new JsonReader(new FileReader(file)));

            return (JsonObject) obj;
        } catch (Exception e) {
        }
        return null;
    }


}