content: /*
   *
   * 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 com.alibaba.cloudapp.starter.base;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.beans.BeansException;
  import org.springframework.context.ApplicationContext;
  import org.springframework.context.ApplicationContextAware;
  import org.springframework.stereotype.Component;
  
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  
  @Component
  public class RefreshManager implements ApplicationContextAware {
      private final static Logger logger = LoggerFactory.getLogger(
              RefreshManager.class);
  
      private  Map<String, RefreshableComponent> components =
              new ConcurrentHashMap<>();
  
      private static ApplicationContext applicationContext;
  
  
      private  void tryRefreshComponent(String key) {
          RefreshableComponent component = components.get(key);
          if (component == null) {
              logger.info("Component not registered by key {}.",  key);
              return;
          }
  
          logger.info("Refreshing component {} as key {} detected changed.",
                  component.getName(), key);
          component.onKeysChanged();
      }
  
      public void register(RefreshableComponent component) {
          components.put(component.bindKey(), component);
      }
  
      public void unregister(RefreshableComponent component) {
          components.remove(component.bindKey());
      }
  
      @Override
      public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
          this.applicationContext = applicationContext;
      }
  
      public static void onPropertiesChanged(String key) {
          if (applicationContext == null) {
              logger.trace("Refresh manager is not initialized yet," +
                      " as application context not found.");
              return;
          }
  
          RefreshManager refreshManager = applicationContext.getBean(
                  RefreshManager.class);
  
          if (refreshManager == null) {
              logger.trace("Refresh manager is not initialized yet.");
              return;
          }
  
          refreshManager.tryRefreshComponent(key);
      }
  }
  