code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.skywalking.oap.server.configuration.apollo;
  
  import com.ctrip.framework.apollo.Config;
  import com.ctrip.framework.apollo.ConfigService;
  import com.google.common.base.Strings;
  import java.util.Optional;
  import java.util.Set;
  import org.apache.skywalking.oap.server.configuration.api.ConfigTable;
  import org.apache.skywalking.oap.server.configuration.api.ConfigWatcherRegister;
  import org.apache.skywalking.oap.server.configuration.api.GroupConfigTable;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class ApolloConfigWatcherRegister extends ConfigWatcherRegister {
      private static final Logger LOGGER = LoggerFactory.getLogger(ApolloConfigWatcherRegister.class);
  
      private final Config configReader;
  
      public ApolloConfigWatcherRegister(ApolloConfigurationCenterSettings settings) {
          super(settings.getPeriod());
  
          final String namespace = settings.getNamespace();
  
          final boolean isDefaultNamespace = Strings.isNullOrEmpty(namespace);
  
          if (isDefaultNamespace) {
              this.configReader = ConfigService.getAppConfig();
              if (LOGGER.isInfoEnabled()) {
                  LOGGER.info("Read dynamic configs from Apollo default namespace");
              }
          } else {
              this.configReader = ConfigService.getConfig(namespace);
              if (LOGGER.isInfoEnabled()) {
                  LOGGER.info("Read dynamic configs from Apollo namespace: {}", namespace);
              }
          }
      }
  
      @Override
      public Optional<ConfigTable> readConfig(Set<String> keys) {
          final ConfigTable configTable = new ConfigTable();
  
          for (final String name : keys) {
              final String value = configReader.getProperty(name, null);
              configTable.add(new ConfigTable.ConfigItem(name, value));
          }
  
          return Optional.of(configTable);
      }
  
      @Override
      public Optional<GroupConfigTable> readGroupConfig(final Set<String> keys) {
          GroupConfigTable groupConfigTable = new GroupConfigTable();
          Set<String> allKeys = this.configReader.getPropertyNames();
  
          keys.forEach(key -> {
              GroupConfigTable.GroupConfigItems groupConfigItems = new GroupConfigTable.GroupConfigItems(key);
              groupConfigTable.addGroupConfigItems(groupConfigItems);
              String groupKey = key + ".";
              if (allKeys != null) {
                  allKeys.stream().filter(it -> it.startsWith(groupKey)).forEach(groupItemKey -> {
                      String itemValue = this.configReader.getProperty(groupItemKey, null);
                      String itemName = groupItemKey.substring(groupKey.length());
                      groupConfigItems.add(new ConfigTable.ConfigItem(itemName, itemValue));
                  });
              }
          });
          return Optional.of(groupConfigTable);
      }
  }
  