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.api.config.annotation;
  
  import com.alibaba.nacos.api.annotation.NacosProperties;
  import com.alibaba.nacos.api.common.Constants;
  import com.alibaba.nacos.api.config.ConfigType;
  import com.alibaba.nacos.api.config.convert.NacosConfigConverter;
  
  import java.lang.annotation.*;
  
  import static com.alibaba.nacos.api.common.Constants.DEFAULT_GROUP;
  
  /**
   * Annotation that marks a method as a listener for Nacos Config change.
   *
   * @author <a href="mailto:mercyblitz@gmail.com">Mercy</a>
   * @since 0.2.0
   */
  @Retention(RetentionPolicy.RUNTIME)
  @Target(ElementType.METHOD)
  @Documented
  public @interface NacosConfigListener {
  
      /**
       * Nacos Group ID
       *
       * @return default value {@link Constants#DEFAULT_GROUP};
       */
      String groupId() default DEFAULT_GROUP;
  
      /**
       * Nacos Data ID
       *
       * @return required value.
       */
      String dataId();
  
      /**
       * Nacos Config type
       *
       * @return "properties"
       */
      ConfigType type() default ConfigType.PROPERTIES;
  
      /**
       * Specify {@link NacosConfigConverter Nacos configuraion convertor} class to convert target type instance.
       *
       * @return The implementation class of {@link NacosConfigConverter}
       */
      Class<? extends NacosConfigConverter> converter() default NacosConfigConverter.class;
  
      /**
       * The {@link NacosProperties} attribute, If not specified, it will use global Nacos Properties.
       *
       * @return the default value is {@link NacosProperties}
       */
      NacosProperties properties() default @NacosProperties;
  
      /**
       * Maximum timeout value of execution in milliseconds, which is used to prevent long-time blocking execution
       * impacting others.
       *
       * @return default value is 1000
       */
      long timeout() default 1000L;
  
  }
  