content: 
  /*
   * Copyright (C) 2012-present the original author or authors.
   * Modified by Ant Group in 2023
   * Copyright 2023 Ant Group
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alipay.antchain.bridge.plugins.manager.pf4j.finder;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.net.URL;
  import java.nio.charset.StandardCharsets;
  import java.util.*;
  
  import com.alipay.antchain.bridge.plugins.lib.pf4j.processor.ExtensionStorage;
  import com.alipay.antchain.bridge.plugins.lib.pf4j.processor.LegacyExtensionStorage;
  import org.pf4j.PluginManager;
  import org.pf4j.PluginWrapper;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * All extensions declared in a plugin are indexed in a file {@code META-INF/extensions.idx}.
   * This class lookup extensions in all extensions index files {@code META-INF/extensions.idx}.
   *
   */
  public class LegacyExtensionFinder extends AbstractExtensionFinder {
  
      private static final Logger log = LoggerFactory.getLogger(LegacyExtensionFinder.class);
  
      public static final String EXTENSIONS_RESOURCE = LegacyExtensionStorage.EXTENSIONS_RESOURCE;
  
      public LegacyExtensionFinder(PluginManager pluginManager) {
          super(pluginManager);
      }
  
      @Override
      public Map<String, Set<String>> readClasspathStorages() {
          log.debug("Reading extensions storages from classpath");
          Map<String, Set<String>> result = new LinkedHashMap<>();
  
          Set<String> bucket = new HashSet<>();
          try {
              Enumeration<URL> urls = getClass().getClassLoader().getResources(EXTENSIONS_RESOURCE);
              if (urls.hasMoreElements()) {
                  collectExtensions(urls, bucket);
              } else {
                  log.debug("Cannot find '{}'", EXTENSIONS_RESOURCE);
              }
  
              debugExtensions(bucket);
  
              result.put(null, bucket);
          } catch (IOException e) {
              log.error(e.getMessage(), e);
          }
  
          return result;
      }
  
      @Override
      public Map<String, Set<String>> readPluginsStorages() {
          log.debug("Reading extensions storages from plugins");
          Map<String, Set<String>> result = new LinkedHashMap<>();
  
          List<PluginWrapper> plugins = pluginManager.getPlugins();
          for (PluginWrapper plugin : plugins) {
              String pluginId = plugin.getDescriptor().getPluginId();
              log.debug("Reading extensions storage from plugin '{}'", pluginId);
              Set<String> bucket = new HashSet<>();
  
              try {
                  log.debug("Read '{}'", EXTENSIONS_RESOURCE);
                  ClassLoader pluginClassLoader = plugin.getPluginClassLoader();
                  try (InputStream resourceStream = pluginClassLoader.getResourceAsStream(EXTENSIONS_RESOURCE)) {
                      if (resourceStream == null) {
                          log.debug("Cannot find '{}'", EXTENSIONS_RESOURCE);
                      } else {
                          collectExtensions(resourceStream, bucket);
                      }
                  }
  
                  debugExtensions(bucket);
  
                  result.put(pluginId, bucket);
              } catch (IOException e) {
                  log.error(e.getMessage(), e);
              }
          }
  
          return result;
      }
  
      private void collectExtensions(Enumeration<URL> urls, Set<String> bucket) throws IOException {
          while (urls.hasMoreElements()) {
              URL url = urls.nextElement();
              log.debug("Read '{}'", url.getFile());
              collectExtensions(url.openStream(), bucket);
          }
      }
  
      private void collectExtensions(InputStream inputStream, Set<String> bucket) throws IOException {
          try (Reader reader = new InputStreamReader(inputStream, StandardCharsets.UTF_8)) {
              ExtensionStorage.read(reader, bucket);
          }
      }
  
  }
  