Class LazySortedMap

  • All Implemented Interfaces:
    java.io.Serializable, java.util.Map, java.util.SortedMap

    public class LazySortedMap
    extends LazyMap
    implements java.util.SortedMap
    Decorates another SortedMap to create objects in the map on demand.

    When the LazyMap.get(Object) method is called with a key that does not exist in the map, the factory is used to create the object. The created object will be added to the map using the requested key.

    For instance:

     Factory factory = new Factory() {
         public Object create() {
             return new Date();
         }
     }
     SortedMap lazy = Lazy.sortedMap(new HashMap(), factory);
     Object obj = lazy.get("NOW");
     
    After the above code is executed, obj will contain a new Date instance. Furthermore, that Date instance is mapped to the "NOW" key in the map.

    Note that LazySortedMap is not synchronized and is not thread-safe. If you wish to use this map from multiple threads concurrently, you must use appropriate synchronization. The simplest approach is to wrap this map using Collections.synchronizedSortedMap(java.util.SortedMap<K, V>). This class may throw exceptions when accessed by concurrent threads without synchronization.

    This class is Serializable from Commons Collections 3.1.

    Since:
    Commons Collections 3.0
    Version:
    $Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
    See Also:
    Serialized Form
    • Nested Class Summary

      • Nested classes/interfaces inherited from interface java.util.Map

        java.util.Map.Entry<K extends java.lang.Object,​V extends java.lang.Object>
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private static long serialVersionUID
      Serialization version
      • Fields inherited from class org.apache.commons.collections.map.LazyMap

        factory
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      protected LazySortedMap​(java.util.SortedMap map, Factory factory)
      Constructor that wraps (not copies).
      protected LazySortedMap​(java.util.SortedMap map, Transformer factory)
      Constructor that wraps (not copies).
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.util.Comparator comparator()  
      static java.util.SortedMap decorate​(java.util.SortedMap map, Factory factory)
      Factory method to create a lazily instantiated sorted map.
      static java.util.SortedMap decorate​(java.util.SortedMap map, Transformer factory)
      Factory method to create a lazily instantiated sorted map.
      java.lang.Object firstKey()  
      protected java.util.SortedMap getSortedMap()
      Gets the map being decorated.
      java.util.SortedMap headMap​(java.lang.Object toKey)  
      java.lang.Object lastKey()  
      java.util.SortedMap subMap​(java.lang.Object fromKey, java.lang.Object toKey)  
      java.util.SortedMap tailMap​(java.lang.Object fromKey)  
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
      • Methods inherited from interface java.util.Map

        clear, compute, computeIfAbsent, computeIfPresent, containsKey, containsValue, equals, forEach, get, getOrDefault, hashCode, isEmpty, merge, put, putAll, putIfAbsent, remove, remove, replace, replace, replaceAll, size
      • Methods inherited from interface java.util.SortedMap

        entrySet, keySet, values
    • Field Detail

      • serialVersionUID

        private static final long serialVersionUID
        Serialization version
        See Also:
        Constant Field Values
    • Constructor Detail

      • LazySortedMap

        protected LazySortedMap​(java.util.SortedMap map,
                                Factory factory)
        Constructor that wraps (not copies).
        Parameters:
        map - the map to decorate, must not be null
        factory - the factory to use, must not be null
        Throws:
        java.lang.IllegalArgumentException - if map or factory is null
      • LazySortedMap

        protected LazySortedMap​(java.util.SortedMap map,
                                Transformer factory)
        Constructor that wraps (not copies).
        Parameters:
        map - the map to decorate, must not be null
        factory - the factory to use, must not be null
        Throws:
        java.lang.IllegalArgumentException - if map or factory is null
    • Method Detail

      • decorate

        public static java.util.SortedMap decorate​(java.util.SortedMap map,
                                                   Factory factory)
        Factory method to create a lazily instantiated sorted map.
        Parameters:
        map - the map to decorate, must not be null
        factory - the factory to use, must not be null
        Throws:
        java.lang.IllegalArgumentException - if map or factory is null
      • decorate

        public static java.util.SortedMap decorate​(java.util.SortedMap map,
                                                   Transformer factory)
        Factory method to create a lazily instantiated sorted map.
        Parameters:
        map - the map to decorate, must not be null
        factory - the factory to use, must not be null
        Throws:
        java.lang.IllegalArgumentException - if map or factory is null
      • getSortedMap

        protected java.util.SortedMap getSortedMap()
        Gets the map being decorated.
        Returns:
        the decorated map
      • firstKey

        public java.lang.Object firstKey()
        Specified by:
        firstKey in interface java.util.SortedMap
      • lastKey

        public java.lang.Object lastKey()
        Specified by:
        lastKey in interface java.util.SortedMap
      • comparator

        public java.util.Comparator comparator()
        Specified by:
        comparator in interface java.util.SortedMap
      • subMap

        public java.util.SortedMap subMap​(java.lang.Object fromKey,
                                          java.lang.Object toKey)
        Specified by:
        subMap in interface java.util.SortedMap
      • headMap

        public java.util.SortedMap headMap​(java.lang.Object toKey)
        Specified by:
        headMap in interface java.util.SortedMap
      • tailMap

        public java.util.SortedMap tailMap​(java.lang.Object fromKey)
        Specified by:
        tailMap in interface java.util.SortedMap