content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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.alibaba.nacos.plugin.encryption;
  
  import com.alibaba.nacos.common.spi.NacosServiceLoader;
  import com.alibaba.nacos.common.utils.StringUtils;
  import com.alibaba.nacos.plugin.encryption.spi.EncryptionPluginService;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Collection;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Optional;
  import java.util.concurrent.ConcurrentHashMap;
  
  /**
   * Encryption Plugin Management.
   *
   * @author lixiaoshuang
   */
  public class EncryptionPluginManager {
      
      private static final Logger LOGGER = LoggerFactory.getLogger(EncryptionPluginManager.class);
      
      private static final Map<String, EncryptionPluginService> ENCRYPTION_SPI_MAP = new ConcurrentHashMap<>();
      
      private static final EncryptionPluginManager INSTANCE = new EncryptionPluginManager();
      
      private EncryptionPluginManager() {
          loadInitial();
      }
      
      /**
       * Load initial.
       */
      private void loadInitial() {
          Collection<EncryptionPluginService> encryptionPluginServices = NacosServiceLoader.load(
                  EncryptionPluginService.class);
          for (EncryptionPluginService encryptionPluginService : encryptionPluginServices) {
              if (StringUtils.isBlank(encryptionPluginService.algorithmName())) {
                  LOGGER.warn("[EncryptionPluginManager] Load EncryptionPluginService({}) algorithmName(null/empty) fail."
                          + " Please Add algorithmName to resolve.", encryptionPluginService.getClass());
                  continue;
              }
              ENCRYPTION_SPI_MAP.put(encryptionPluginService.algorithmName(), encryptionPluginService);
              LOGGER.info("[EncryptionPluginManager] Load EncryptionPluginService({}) algorithmName({}) successfully.",
                      encryptionPluginService.getClass(), encryptionPluginService.algorithmName());
          }
      }
      
      /**
       * Get EncryptionPluginManager instance.
       *
       * @return EncryptionPluginManager
       */
      public static EncryptionPluginManager instance() {
          return INSTANCE;
      }
      
      /**
       * get EncryptionPluginService instance.
       *
       * @param algorithmName algorithmName, mark a EncryptionPluginService instance.
       * @return EncryptionPluginService instance.
       */
      public Optional<EncryptionPluginService> findEncryptionService(String algorithmName) {
          return Optional.ofNullable(ENCRYPTION_SPI_MAP.get(algorithmName));
      }
      
      /**
       * Injection realization.
       *
       * @param encryptionPluginService Encryption implementation
       */
      public static synchronized void join(EncryptionPluginService encryptionPluginService) {
          if (Objects.isNull(encryptionPluginService)) {
              return;
          }
          ENCRYPTION_SPI_MAP.put(encryptionPluginService.algorithmName(), encryptionPluginService);
          LOGGER.info("[EncryptionPluginManager] join successfully.");
      }
      
  }
  