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    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,
    13   * software distributed under the License is distributed on an
    14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    15   * KIND, either express or implied.  See the License for the
    16   * specific language governing permissions and limitations
    17   * under the License.
    18   */
    19  package org.apache.myfaces.shared_orchestra.util;
    20
    21  import java.util.Enumeration;
    22
    23  /**
    24   * Enumeration without elements
    25   *
    26   * @author Anton Koinov (latest modification by $Author: grantsmith $)
    27   * @version $Revision: 472630 $ $Date: 2006-11-08 15:40:03 -0500 (Wed, 08 Nov 2006) $
    28   */
    29  public final class NullEnumeration implements Enumeration
    30  {
    31      private static final NullEnumeration s_nullEnumeration = new NullEnumeration();
    32
    33      public static final NullEnumeration instance()
    34      {
    35          return s_nullEnumeration;
    36      }
    37
    38      public boolean hasMoreElements()
    39      {
    40          return false;
    41      }
    42
    43      public Object nextElement()
    44      {
    45          throw new UnsupportedOperationException("NullEnumeration has no elements");
    46      }
    47  }