Class CustomCollectionEditor

java.lang.Object
java.beans.PropertyEditorSupport
org.springframework.beans.propertyeditors.CustomCollectionEditor
All Implemented Interfaces:
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.

Since:
1.1.3
Author:
Juergen Hoeller
See Also:
  • Constructor Details

    • CustomCollectionEditor

      public CustomCollectionEditor(Class<? extends Collection> collectionType)
      Create a new CustomCollectionEditor for the given target type, keeping an incoming null as-is.
      Parameters:
      collectionType - the target type, which needs to be a sub-interface of Collection or a concrete Collection class
      See Also:
    • 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.

      Parameters:
      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)
      See Also:
  • Method Details

    • setAsText

      public void setAsText(String text) throws IllegalArgumentException
      Convert the given text value to a Collection with a single element.
      Specified by:
      setAsText in interface PropertyEditor
      Overrides:
      setAsText in class PropertyEditorSupport
      Throws:
      IllegalArgumentException
    • setValue

      public void setValue(@Nullable Object value)
      Convert the given value to a Collection of the target type.
      Specified by:
      setValue in interface PropertyEditor
      Overrides:
      setValue in class PropertyEditorSupport
    • createCollection

      protected Collection<Object> createCollection(Class<? extends Collection> collectionType, int initialCapacity)
      Create a Collection of the given type, with the given initial capacity (if supported by the Collection type).
      Parameters:
      collectionType - a sub-interface of Collection
      initialCapacity - the initial capacity
      Returns:
      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.

      See Also:
    • 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.

      Parameters:
      element - the source element
      Returns:
      the element to be used in the target Collection
      See Also:
    • getAsText

      @Nullable public String getAsText()
      This implementation returns null to indicate that there is no appropriate text representation.
      Specified by:
      getAsText in interface PropertyEditor
      Overrides:
      getAsText in class PropertyEditorSupport