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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements.  See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache License, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License.  You may obtain a copy of the License at
    8    *
    9    *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17  package javax.jdo.annotations;
    18
    19  import java.lang.annotation.ElementType;
    20  import java.lang.annotation.Retention;
    21  import java.lang.annotation.RetentionPolicy;
    22  import java.lang.annotation.Target;
    23
    24  /**
    25   * Annotation for a database index. Used for database schema
    26   * generation to create indexes.
    27   * Corresponds to the xml element "index".
    28   *
    29   * @version 2.1
    30   * @since 2.1
    31   */
    32  @Target({ElementType.TYPE, ElementType.FIELD, ElementType.METHOD})
    33  @Retention(RetentionPolicy.RUNTIME)
    34  public @interface Index
    35  {
    36      /** Name of the index
    37       * @return the name of the index
    38       */
    39      String name() default "";
    40
    41      /** Table for the index. This is needed iff annotating a type where
    42       * the index is not defined on the primary table for the type.
    43       * @return the table on which the index is defined
    44       */
    45      String table() default "";
    46
    47      /** Whether this index is unique
    48       * @return whether this index is unique
    49       */
    50      String unique() default "";
    51
    52      /** Member (field and property) names that compose this index.
    53       * @return member names that compose this index
    54       */
    55      String[] members() default {};
    56
    57      /** Columns that compose this index.
    58       * @return columns that compose this index
    59       */
    60      Column[] columns() default {};
    61  }