A message provider with i18n for the bukkit plataform

DefaultMessageProvider.java

package braayy.lib.provider.impl;

import braayy.lib.provider.MessageProvider;
import org.bukkit.ChatColor;
import org.bukkit.command.CommandSender;
import org.bukkit.configuration.ConfigurationSection;
import org.bukkit.configuration.file.YamlConfiguration;
import org.bukkit.entity.Player;
import org.bukkit.plugin.Plugin;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.*;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.logging.Level;

public class DefaultMessageProvider implements MessageProvider {

    private final Map<String, Map<String, String[]>> messageMap;
    private String defaultLanguage;

    public DefaultMessageProvider() {
        this.messageMap = new HashMap<>();
        this.defaultLanguage = "en_us";
    }

    @Override
    public void enable(Plugin plugin) {
        try {
            long start = System.currentTimeMillis();

            File i18nFolder = new File(plugin.getDataFolder(), "i18n");

            if (!i18nFolder.exists()) {
                if (!i18nFolder.mkdirs()) {
                    throw new IllegalStateException("Could not make i18n folder");
                }

                this.saveDefaultLangFiles(i18nFolder);
            } else {
                this.loadLangFiles(i18nFolder);
            }

            long diff = System.currentTimeMillis() - start;

            for (String lang : this.messageMap.keySet()) {
                plugin.getLogger().info(lang + " locale was loaded");
            }

            plugin.getLogger().info("Message service was enabled successfully " + diff + "ms");
        } catch (Exception ex) {
            plugin.getLogger().log(Level.SEVERE, "Could not load messages.yml", ex);
        }
    }

    @Override
    public String[] get(String key, Object... args) {
        return this.get(this.defaultLanguage, key, args);
    }

    @Override
    public String[] get(String locale, String key, Object... args) {
        if ((args.length & 1) != 0) {
            throw new IllegalArgumentException("args length must be even");
        }

        Map<String, String[]> localeMap = this.messageMap.get(locale);

        Objects.requireNonNull(localeMap, locale + " locale was not found");

        String[] messageArray = localeMap.get(key);

        Objects.requireNonNull(messageArray, key + " message was not found");

        String[] appliedArray = new String[messageArray.length];

        for (int i = 0 ; i < messageArray.length; i++) {
            appliedArray[i] = applyParameters(messageArray[i], args);
        }

        return appliedArray;
    }

    @Override
    public void sendMessage(CommandSender sender, String key, Object... args) {
        String locale = (sender instanceof Player) ? ((Player) sender).getLocale() : this.defaultLanguage;

        String[] messageArray = this.get(locale, key, args);

        sender.sendMessage(messageArray);
    }

    @Override
    public void setDefaultLanguage(String defaultLanguage) {
        this.defaultLanguage = defaultLanguage;
    }

    private void loadLangFiles(File i18nFolder) {
        File[] langFiles = i18nFolder.listFiles();

        if (langFiles == null) {
            throw new IllegalStateException("Could not list i18n folder");
        }

        for (File langFile : langFiles) {
            YamlConfiguration yaml = YamlConfiguration.loadConfiguration(langFile);

            String lang = langFile.getName();
            lang = lang.substring(0, lang.length() - 4);

            this.searchMessages(lang, yaml);
        }
    }

    private void saveDefaultLangFiles(File i18nFolder) throws Exception {
        File ownFile = new File(MessageProvider.class.getProtectionDomain().getCodeSource().getLocation().getPath());
        JarFile jarFile = new JarFile(ownFile);

        Enumeration<JarEntry> enumeration = jarFile.entries();

        while (enumeration.hasMoreElements()) {
            JarEntry entry = enumeration.nextElement();

            if (entry.getName().startsWith("i18n/") && !entry.isDirectory()) {
                String fileName = entry.getName().substring(5);
                File langFile = new File(i18nFolder, fileName);

                FileOutputStream output = new FileOutputStream(langFile);
                InputStream input = jarFile.getInputStream(entry);

                byte[] buffer = new byte[2048];
                int read;

                while ((read = input.read(buffer)) != -1) {
                    output.write(buffer, 0, read);
                }

                output.flush();

                YamlConfiguration yaml = YamlConfiguration.loadConfiguration(langFile);

                String lang = langFile.getName();
                lang = lang.substring(0, lang.length() - 4);

                this.searchMessages(lang, yaml);
            }
        }
    }

    private void searchMessages(String locale, ConfigurationSection section) {
        for (String key : section.getKeys(false)) {
            String path = section.getCurrentPath() + '.' + key;
            if (path.startsWith(".")) path = path.substring(1);

            if (section.isConfigurationSection(key)) {
                this.searchMessages(locale, section.getConfigurationSection(key));
            } else if (section.isString(key)) {
                String message = ChatColor.translateAlternateColorCodes('&', section.getString(key));

                Map<String, String[]> localeMap = this.messageMap.getOrDefault(locale, new HashMap<>());

                localeMap.put(key, new String[] { message });

                this.messageMap.put(locale, localeMap);
            } else if (section.isList(key)) {
                List<String> messageList = section.getStringList(key);

                messageList.replaceAll(string -> ChatColor.translateAlternateColorCodes('&', string));

                Map<String, String[]> localeMap = this.messageMap.getOrDefault(locale, new HashMap<>());

                localeMap.put(path, messageList.toArray(new String[0]));

                this.messageMap.put(locale, localeMap);
            }
        }
    }

    private static String applyParameters(String string, Object... args) {
        for (int i = 0; i < args.length; i += 2) {
            String key = (String) args[i];
            String value = args[i + 1].toString();

            string = string.replace("{" + key + "}", value);
        }

        return string;
    }

}

MessageProvider.java

package braayy.lib.provider;

import org.bukkit.command.CommandSender;
import org.bukkit.plugin.Plugin;

public interface MessageProvider {

    /**
     * Configures the service
     * @param plugin The plugin who is enabling this service
     */
    void enable(Plugin plugin);

    /**
     * @param key The key of the message
     * @param args The arguments for the message
     * @return The formatted message
     */
    String[] get(String key, Object... args);

    /**
     * @param locale The locale of the message
     * @param key The key of the message
     * @param args The arguments for the message
     * @return The formatted message
     */
    String[] get(String locale, String key, Object... args);

    /**
     * @param sender The sender who will receive this message
     * @param key The key of the message
     * @param args The arguments for the message
     */
    void sendMessage(CommandSender sender, String key, Object... args);

    /**
     * @param defaultLanguage The default language
     */
    void setDefaultLanguage(String defaultLanguage);
}