001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.hadoop.classification;
019    
020    import java.lang.annotation.Documented;
021    import java.lang.annotation.Retention;
022    import java.lang.annotation.RetentionPolicy;
023    
024    /**
025     * Annotation to inform users of how much to rely on a particular package,
026     * class or method not changing over time.
027     * </ul>
028     */
029    @InterfaceAudience.Public
030    @InterfaceStability.Evolving
031    public class InterfaceStability {
032      /**
033       * Can evolve while retaining compatibility for minor release boundaries.; 
034       * can break compatibility only at major release (ie. at m.0).
035       */
036      @Documented
037      @Retention(RetentionPolicy.RUNTIME)
038      public @interface Stable {};
039      
040      /**
041       * Evolving, but can break compatibility at minor release (i.e. m.x)
042       */
043      @Documented
044      @Retention(RetentionPolicy.RUNTIME)
045      public @interface Evolving {};
046      
047      /**
048       * No guarantee is provided as to reliability or stability across any
049       * level of release granularity.
050       */
051      @Documented
052      @Retention(RetentionPolicy.RUNTIME)
053      public @interface Unstable {};
054    }