类 CustomCollectionEditor

  • 所有已实现的接口:
    PropertyEditor

    public class CustomCollectionEditor
    extends PropertyEditorSupport
    Property editor for Collections, converting any source Collection to a given target Collection type.

    By default registered for Set, SortedSet and List, to automatically convert any given Collection to one of those target types if the type does not match the target property.

    从以下版本开始:
    1.1.3
    作者:
    Juergen Hoeller
    另请参阅:
    Collection, Set, SortedSet, List
    • 构造器详细资料

      • CustomCollectionEditor

        public CustomCollectionEditor​(Class<? extends Collection> collectionType,
                                      boolean nullAsEmptyCollection)
        Create a new CustomCollectionEditor for the given target type.

        If the incoming value is of the given type, it will be used as-is. If it is a different Collection type or an array, it will be converted to a default implementation of the given Collection type. If the value is anything else, a target Collection with that single value will be created.

        The default Collection implementations are: ArrayList for List, TreeSet for SortedSet, and LinkedHashSet for Set.

        参数:
        collectionType - the target type, which needs to be a sub-interface of Collection or a concrete Collection class
        nullAsEmptyCollection - whether to convert an incoming null value to an empty Collection (of the appropriate type)
        另请参阅:
        Collection, ArrayList, TreeSet, LinkedHashSet
    • 方法详细资料

      • createCollection

        protected Collection<ObjectcreateCollection​(Class<? extends Collection> collectionType,
                                                      int initialCapacity)
        Create a Collection of the given type, with the given initial capacity (if supported by the Collection type).
        参数:
        collectionType - a sub-interface of Collection
        initialCapacity - the initial capacity
        返回:
        the new Collection instance
      • alwaysCreateNewCollection

        protected boolean alwaysCreateNewCollection()
        Return whether to always create a new Collection, even if the type of the passed-in Collection already matches.

        Default is "false"; can be overridden to enforce creation of a new Collection, for example to convert elements in any case.

        另请参阅:
        convertElement(java.lang.Object)
      • convertElement

        protected Object convertElement​(Object element)
        Hook to convert each encountered Collection/array element. The default implementation simply returns the passed-in element as-is.

        Can be overridden to perform conversion of certain elements, for example String to Integer if a String array comes in and should be converted to a Set of Integer objects.

        Only called if actually creating a new Collection! This is by default not the case if the type of the passed-in Collection already matches. Override alwaysCreateNewCollection() to enforce creating a new Collection in every case.

        参数:
        element - the source element
        返回:
        the element to be used in the target Collection
        另请参阅:
        alwaysCreateNewCollection()