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.csp.sentinel.cluster.server;
  
  import com.alibaba.csp.sentinel.cluster.TokenService;
  import com.alibaba.csp.sentinel.log.RecordLog;
  import com.alibaba.csp.sentinel.spi.SpiLoader;
  
  /**
   * @author Eric Zhao
   * @since 1.4.0
   */
  public final class TokenServiceProvider {
  
      private static TokenService service = null;
  
      static {
          resolveTokenServiceSpi();
      }
  
      public static TokenService getService() {
          return service;
      }
  
      private static void resolveTokenServiceSpi() {
          service = SpiLoader.of(TokenService.class).loadFirstInstanceOrDefault();
          if (service != null) {
              RecordLog.info("[TokenServiceProvider] Global token service resolved: "
                  + service.getClass().getCanonicalName());
          } else {
              RecordLog.warn("[TokenServiceProvider] Unable to resolve TokenService: no SPI found");
          }
      }
  }
  