text: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.guacamole.net.auth.simple;
  
  import java.util.Collections;
  import java.util.Set;
  import org.apache.guacamole.GuacamoleException;
  import org.apache.guacamole.GuacamoleSecurityException;
  import org.apache.guacamole.net.auth.RelatedObjectSet;
  
  /**
   * A read-only implementation of RelatedObjectSet which uses a backing Set
   * of identifiers to determine which objects are present.
   */
  public class SimpleRelatedObjectSet implements RelatedObjectSet {
  
      /**
       * A set containing the identifiers of all objects currently present.
       */
      private Set<String> identifiers = Collections.emptySet();
  
      /**
       * Creates a new empty SimpleRelatedObjectSet. If you are not extending
       * SimpleRelatedObjectSet and only need an immutable, empty
       * RelatedObjectSet, consider using {@link RelatedObjectSet#EMPTY_SET}
       * instead.
       */
      public SimpleRelatedObjectSet() {
      }
  
      /**
       * Creates a new SimpleRelatedObjectSet which contains the objects having
       * the identifiers within the given Set. The given Set backs the contents
       * of the new SimpleRelatedObjectSet. While the SimpleRelatedObjectSet is
       * read-only, any changes to the underlying Set will be reflected in the
       * SimpleRelatedObjectSet.
       *
       * @param identifiers
       *     The Set containing the identifiers of all objects which should be
       *     present within the new SimpleRelatedObjectSet.
       */
      public SimpleRelatedObjectSet(Set<String> identifiers) {
          this.identifiers = identifiers;
      }
  
      /**
       * Replaces the Set of object identifiers which backs this
       * SimpleRelatedObjectSet. Future function calls on this
       * SimpleRelatedObjectSet will instead use the provided Set.
       *
       * @param identifiers
       *     The Set containing the identifiers of all objects which should be
       *     present within this SimpleRelatedObjectSet.
       */
      protected void setObjects(Set<String> identifiers) {
          this.identifiers = identifiers;
      }
  
      @Override
      public Set<String> getObjects() {
          return identifiers;
      }
  
      @Override
      public void addObjects(Set<String> identifiers) throws GuacamoleException {
          throw new GuacamoleSecurityException("Permission denied.");
      }
  
      @Override
      public void removeObjects(Set<String> identifiers) throws GuacamoleException {
          throw new GuacamoleSecurityException("Permission denied.");
      }
  
  }
  