content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * Lesser General Public License for more details.
   *
   * For further information about Alkacon Software, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  package org.opencms.util;
  
  import org.opencms.jsp.util.CmsJspContentAccessValueWrapper;
  
  import java.util.Collection;
  import java.util.Enumeration;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.commons.collections.Transformer;
  import org.apache.commons.collections.map.LRUMap;
  import org.apache.commons.collections.map.LazyMap;
  
  /**
   * Provides Map wrapping utility functions for Java generics.<p>
   *
   * @since 8.0.0
   */
  public final class CmsCollectionsGenericWrapper {
  
      /**
       *  Wrapper for lazy maps providing a better containsKey implementation.<p>
       *
       * @param <K> the key type
       * @param <V> the value type
       */
      public static class MapWrapper<K, V> implements Map<K, V> {
  
          /** The wrapped map. */
          private Map<K, V> m_map;
  
          /**
           * Constructor.<p>
           *
           * @param map the map to wrap
           */
          MapWrapper(Map<K, V> map) {
              m_map = map;
          }
  
          /**
           *
           * @see java.util.Map#clear()
           */
          @Override
          public void clear() {
  
              m_map.clear();
          }
  
          /**
           * @see java.util.Map#containsKey(java.lang.Object)
           */
          @Override
          public boolean containsKey(Object key) {
  
              V value = m_map.get(key);
              if (value instanceof CmsJspContentAccessValueWrapper) {
                  return ((CmsJspContentAccessValueWrapper)value).getExists();
              } else {
                  return value != null;
              }
          }
  
          /**
           * @see java.util.Map#containsValue(java.lang.Object)
           */
          @Override
          public boolean containsValue(Object value) {
  
              return m_map.containsValue(value);
          }
  
          /**
           * @see java.util.Map#entrySet()
           */
          @Override
          public Set<java.util.Map.Entry<K, V>> entrySet() {
  
              return m_map.entrySet();
          }
  
          /**
           * @see java.util.Map#equals(java.lang.Object)
           */
          @Override
          public boolean equals(Object o) {
  
              return m_map.equals(o);
          }
  
          /**
           * @see java.util.Map#get(java.lang.Object)
           */
          @Override
          public V get(Object key) {
  
              return m_map.get(key);
          }
  
          /**
           * @see java.util.Map#hashCode()
           */
          @Override
          public int hashCode() {
  
              return m_map.hashCode();
          }
  
          /**
           * @see java.util.Map#isEmpty()
           */
          @Override
          public boolean isEmpty() {
  
              return m_map.isEmpty();
          }
  
          /**
           * @see java.util.Map#keySet()
           */
          @Override
          public Set<K> keySet() {
  
              return m_map.keySet();
          }
  
          /**
           * @see java.util.Map#put(java.lang.Object, java.lang.Object)
           */
          @Override
          public V put(K key, V value) {
  
              return m_map.put(key, value);
          }
  
          /**
           * @see java.util.Map#putAll(java.util.Map)
           */
          @Override
          public void putAll(Map<? extends K, ? extends V> m) {
  
              m_map.putAll(m);
          }
  
          /**
           * @see java.util.Map#remove(java.lang.Object)
           */
          @Override
          public V remove(Object key) {
  
              return m_map.remove(key);
          }
  
          /**
           * @see java.util.Map#size()
           */
          @Override
          public int size() {
  
              return m_map.size();
          }
  
          /**
           * @see java.util.Map#values()
           */
          @Override
          public Collection<V> values() {
  
              return m_map.values();
          }
  
      }
  
      /**
       * Hides the public constructor.<p>
       */
      private CmsCollectionsGenericWrapper() {
  
          // empty
      }
  
      /**
       * Provides a wrapper to access the {@link LazyMap} functionality that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of keys maintained by the returned map
       * @param <V> the type of mapped values
       * @param T the transformer to use for the Lazy Map
       *
       * @return a {@link LazyMap} of the required generic type
       */
      public static <K, V> Map<K, V> createLazyMap(Transformer T) {
  
          return new MapWrapper<K, V>(LazyMap.decorate(new HashMap<K, V>(), T));
      }
  
      /**
       * Provides a wrapper to create a {@link LRUMap} that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of keys maintained by the returned map
       * @param <V> the type of mapped values
       *
       * @return a {@link LRUMap} of the required generic type
       */
      @SuppressWarnings("unchecked")
      public static <K, V> Map<K, V> createLRUMap() {
  
          return new LRUMap();
      }
  
      /**
       * Provides a wrapper to create a {@link LRUMap} with the given size that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of keys maintained by the returned map
       * @param <V> the type of mapped values
       * @param size the initial size of the created Map
       *
       * @return a {@link LRUMap} with the given size of the required generic type
       */
      @SuppressWarnings("unchecked")
      public static <K, V> Map<K, V> createLRUMap(int size) {
  
          return new LRUMap(size);
      }
  
      /**
       * Provides a wrapper to convert an enumeration that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of the returned enumeration elements
       * @param enumeration the enumeration to be converted
       *
       * @return a {@link Enumeration} with the required generic type
       */
      @SuppressWarnings("unchecked")
      public static <K> Enumeration<K> enumeration(Enumeration<?> enumeration) {
  
          return (Enumeration<K>)enumeration;
      }
  
      /**
       * Provides a wrapper to convert an object into a list that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of the returned list elements
       * @param o the object to be converted
       *
       * @return a {@link List} with the required generic type
       */
      @SuppressWarnings("unchecked")
      public static <K> List<K> list(Object o) {
  
          return (List<K>)o;
      }
  
      /**
       * Provides a wrapper to convert an object into a map that avoids warnings with Java 1.5 generic code.<p>
       *
       * @param <K> the type of keys maintained by the returned map
       * @param <V> the type of mapped values
       * @param o the object to be converted
       *
       * @return a {@link Map} of the required generic type
       */
      @SuppressWarnings("unchecked")
      public static <K, V> Map<K, V> map(Object o) {
  
          return (Map<K, V>)o;
      }
  }