1 /*   2  * Licensed to the Apache Software Foundation (ASF) under one   3  * or more contributor license agreements.  See the NOTICE file   4  * distributed with this work for additional information   5  * regarding copyright ownership.  The ASF licenses this file   6  * to you under the Apache License, Version 2.0 (the   7  * "License"); you may not use this file except in compliance   8  * with the License.  You may obtain a copy of the License at   9  *  10  *     http://www.apache.org/licenses/LICENSE-2.0  11  *  12  * Unless required by applicable law or agreed to in writing, software  13  * distributed under the License is distributed on an "AS IS" BASIS,  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  15  * See the License for the specific language governing permissions and  16  * limitations under the License.  17  */  18 package org.apache.hadoop.classification;   19   20 import java.lang.annotation.Documented;   21   22 /**  23  * Annotation to inform users of a package, class or method‘s intended audience.  24  */  25 @InterfaceAudience.Public   26 @InterfaceStability.Evolving   27 public class InterfaceAudience {   28   /**  29    * Intended for use by any project or application.  30    */  31   @Documented public @interface Public {};   32      33   /**  34    * Intended only for the project(s) specified in the annotation.  35    * For example, "Common", "HDFS", "MapReduce", "ZooKeeper", "HBase".  36    */  37   @Documented public @interface LimitedPrivate {   38     String[] value();   39   };   40      41   /**  42    * Intended for use only within Hadoop itself.  43    */  44   @Documented public @interface Private {};   45   46   private InterfaceAudience() {} // Audience can‘t exist on its own   47 }