feat(I18n): add internationalization to the program

* add internationalization class I18n

core/src/main/java/cn/harryh/arkpets/ArkConfig.java

@@ -65,6 +65,7 @@ public class ArkConfig {
     public float      physic_static_friction_acc;
     public float      physic_speed_limit_x;
     public float      physic_speed_limit_y;
+    public String     prefer_language;
 
     private ArkConfig() {
     }

core/src/main/java/cn/harryh/arkpets/i18n/I18n.java

@@ -0,0 +1,51 @@
+package cn.harryh.arkpets.i18n;
+
+
+import cn.harryh.arkpets.ArkConfig;
+import cn.harryh.arkpets.utils.Logger;
+
+import java.util.*;
+
+
+public final class I18n {
+
+    private I18n() {
+    }
+
+    public static Locales.SupportedLocale getCurrentLocale() {
+        try {
+            return Locales.getLocaleByName(Objects.requireNonNull(ArkConfig.getConfig()).prefer_language);
+        } catch (IllegalStateException e) {
+            return Locales.DEFAULT;
+        }
+    }
+
+    public static ResourceBundle getResourceBundle() {
+        return getCurrentLocale().getResourceBundle();
+    }
+
+    public static String i18n(String key, Object... formatArgs) {
+        try {
+            return String.format(getResourceBundle().getString(key), formatArgs);
+        } catch (MissingResourceException e) {
+            Logger.error("I18n", "Cannot find key " + key + " in resource bundle" + e);
+        } catch (IllegalFormatException e) {
+            Logger.error("I18n", "Illegal format string, key=" + key + ", args=" + Arrays.toString(formatArgs) + e);
+        }
+
+        return key + Arrays.toString(formatArgs);
+    }
+
+    public static String i18n(String key) {
+        try {
+            return getResourceBundle().getString(key);
+        } catch (MissingResourceException e) {
+            Logger.error("I18n", "Cannot find key " + key + " in resource bundle", e);
+            return key;
+        }
+    }
+
+    public static boolean hasKey(String key) {
+        return getResourceBundle().containsKey(key);
+    }
+}

core/src/main/java/cn/harryh/arkpets/i18n/Locales.java

@@ -0,0 +1,77 @@
+package cn.harryh.arkpets.i18n;
+
+import java.util.List;
+import java.util.Locale;
+import java.util.ResourceBundle;
+
+
+public final class Locales {
+    public static final SupportedLocale DEFAULT = new SupportedLocale(Locale.getDefault(), "lang.default");
+    /**
+     * English
+     */
+    public static final SupportedLocale EN = new SupportedLocale(Locale.ROOT);
+    /**
+     * Traditional Chinese
+     */
+    public static final SupportedLocale ZH_TW = new SupportedLocale(Locale.TRADITIONAL_CHINESE);
+    /**
+     * Simplified Chinese
+     */
+    public static final SupportedLocale ZH_CN = new SupportedLocale(Locale.SIMPLIFIED_CHINESE);
+
+    private Locales() {
+    }
+
+    public static SupportedLocale getLocaleByName(String name) {
+        if (name == null) return DEFAULT;
+        return switch (name.toLowerCase(Locale.ROOT)) {
+            case "en" -> EN;
+            case "zh_tw" -> ZH_TW;
+            case "zh_cn" -> ZH_CN;
+            default -> DEFAULT;
+        };
+    }
+
+    public static List<String> getSupportedLanguages() {
+        return List.of("en", "zh_tw", "zh_cn");
+    }
+
+    public static String getNameByLocale(SupportedLocale locale) {
+        if (locale == EN) return "en";
+        if (locale == ZH_TW) return "zh_tw";
+        if (locale == ZH_CN) return "zh_cn";
+        if (locale == DEFAULT) return "def";
+        throw new IllegalArgumentException("Unknown locale: " + locale);
+    }
+
+    public static class SupportedLocale {
+        private final Locale locale;
+        private final String name;
+        private final ResourceBundle resourceBundle;
+
+        SupportedLocale(Locale locale) {
+            this(locale, null);
+        }
+
+        SupportedLocale(Locale locale, String name) {
+            this.locale = locale;
+            this.name = name;
+            resourceBundle = ResourceBundle.getBundle("lang.I18N", locale);
+        }
+
+        public Locale getLocale() {
+            return locale;
+        }
+
+        public ResourceBundle getResourceBundle() {
+            return resourceBundle;
+        }
+
+        public String getName(ResourceBundle newResourceBundle) {
+            if (name == null) return resourceBundle.getString("lang");
+            else return newResourceBundle.getString(name);
+        }
+
+    }
+}

core/src/main/resources/lang/I18N.properties

@@ -0,0 +1 @@
+app.title = Ark pet

core/src/main/resources/lang/I18N_zh_cn.properties

@@ -0,0 +1 @@
+app.title = Ark Pet

core/src/main/resources/lang/I18N_zh_tw.properties

@@ -0,0 +1 @@
+app.title = Ark pet

desktop/src/main/resources/ArkPetsConfigDefault.json

@@ -20,5 +20,6 @@
     "physic_gravity_acc":800.0,
     "physic_speed_limit_x":1000.0,
     "physic_speed_limit_y":1000.0,
-    "physic_static_friction_acc":500.0
-}
+    "physic_static_friction_acc":500.0,
+    "prefer_language": "zh_cn"
+}