Java tutorial
/* * This file is part of LanternServer, licensed under the MIT License (MIT). * * Copyright (c) LanternPowered <https://www.lanternpowered.org> * Copyright (c) SpongePowered <https://www.spongepowered.org> * Copyright (c) contributors * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the Software), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package org.lanternpowered.server.text.translation; import static com.google.common.base.Preconditions.checkArgument; import static com.google.common.base.Preconditions.checkNotNull; import static org.lanternpowered.server.util.Conditions.checkNotNullOrEmpty; import com.github.benmanes.caffeine.cache.Caffeine; import com.github.benmanes.caffeine.cache.LoadingCache; import com.google.common.collect.Sets; import org.lanternpowered.api.asset.Asset; import org.lanternpowered.server.asset.ReloadListener; import org.lanternpowered.server.game.Lantern; import org.spongepowered.api.text.translation.ResourceBundleTranslation; import org.spongepowered.api.text.translation.Translation; import java.io.IOException; import java.io.InputStream; import java.util.HashMap; import java.util.Locale; import java.util.Map; import java.util.Optional; import java.util.PropertyResourceBundle; import java.util.ResourceBundle; import java.util.Set; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import javax.annotation.Nullable; public final class LanternTranslationManager implements TranslationManager, ReloadListener { private static class ResourceKey { private final String name; @Nullable private final Locale locale; ResourceKey(String name, @Nullable Locale locale) { this.name = name; this.locale = locale; } @Override public int hashCode() { return 31 * this.name.hashCode() + (this.locale == null ? 0 : this.locale.hashCode()); } } private final LoadingCache<ResourceKey, Optional<ResourceBundle>> resourceBundlesCache = Caffeine.newBuilder() .build(key -> { final Locale locale = key.locale == null ? Locale.ENGLISH : key.locale; Optional<ResourceBundle> optBundle = this.load(key.name, locale); if (!optBundle.isPresent() && locale != Locale.ENGLISH) { optBundle = this.load(key.name, Locale.ENGLISH); } return optBundle; }); private Optional<ResourceBundle> load(String name, Locale locale) throws Exception { if (this.bundles.containsKey(locale)) { for (ResourceBundle resourceBundle : this.bundles.get(locale)) { if (resourceBundle.containsKey(name)) { return Optional.of(resourceBundle); } } } return Optional.empty(); } private final ConcurrentMap<Locale, Set<ResourceBundle>> bundles = new ConcurrentHashMap<>(); private final Map<Asset, Locale> entries = new HashMap<>(); @Override public void addResourceBundle(Asset asset, Locale locale) { checkNotNull(asset, "asset"); checkNotNull(locale, "locale"); synchronized (this.entries) { checkArgument(!this.entries.containsKey(asset), "The asset %s is already added to this translation manager.", asset.getId()); this.entries.put(asset, locale); this.loadAssetBundle(asset, locale, true); } } private void loadAssetBundle(Asset asset, Locale locale, boolean refresh) { try { final InputStream inputStream = asset.getUrl().openStream(); try { final ResourceBundle bundle = new PropertyResourceBundle(inputStream); this.bundles.computeIfAbsent(locale, locale0 -> Sets.newConcurrentHashSet()).add(bundle); if (refresh) { final Set<ResourceKey> refreshKeys = Sets.newHashSet(); for (ResourceKey key : this.resourceBundlesCache.asMap().keySet()) { Locale locale1 = key.locale == null ? Locale.ENGLISH : key.locale; if (locale1.equals(locale) && bundle.containsKey(key.name)) { refreshKeys.add(key); } } if (!refreshKeys.isEmpty()) { this.resourceBundlesCache.invalidateAll(refreshKeys); } } } catch (IOException e) { Lantern.getLogger().warn("Unable to create the resource bundle for: " + asset.getId(), e); } } catch (IOException e) { Lantern.getLogger().warn("Unable to open the asset stream for: " + asset.getId(), e); } } @Override public Translation get(final String key) { return new ResourceBundleTranslation(checkNotNullOrEmpty(key, "key"), locale -> this.resourceBundlesCache.get(new ResourceKey(key, locale)).orElse(null)); } @Override public Optional<Translation> getIfPresent(String key) { checkNotNullOrEmpty(key, "key"); if (this.resourceBundlesCache.get(new ResourceKey(key, null)).isPresent()) { return Optional.of(this.get(key)); } return Optional.empty(); } @Override public void onReload() { synchronized (this.entries) { this.bundles.clear(); this.resourceBundlesCache.invalidateAll(); for (Map.Entry<Asset, Locale> entry : this.entries.entrySet()) { this.loadAssetBundle(entry.getKey(), entry.getValue(), false); } } } }