Package org.apache.cayenne

Interface ValueHolder<E>

  • All Superinterfaces:
    Serializable
    All Known Implementing Classes:
    IndexPropertyList, PersistentObjectHolder, PersistentObjectList, PersistentObjectMap, PersistentObjectSet, ToManyList, ToManySet
    public interface ValueHolder<E>
extends Serializable
    Provides a level of indirection for property value access, most often used for deferred faulting of to-one relationships. A ValueHolder abstracts how a property value is obtained (fetched from DB, etc.), thus simplifying design of an object that uses it.

    Here is an example of a bean property implemented using ValueHolder: 

     protected ValueHolder someProperty;
 
 public SomeClass getSomeProperty() {
     return (SomeClass) somePropertyHolder.getValue(SomeClass.class);
 }
 
 public void setSomeProperty(SomeClass newValue) {
     somePropertyHolder.setValue(SomeClass.class, newValue);
 }
    Since:
    1.2

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      E getValue()
      Returns an object stored by this ValueHolder.
      E getValueDirectly()
      Retrieves ValueHolder value without triggering fault resolution.
      void invalidate()
      Turns a ValueHolder into a fault.
      boolean isFault()
      Returns true if the internal value is not yet resolved.
      E setValue​(E value)
      Sets an object stored by this ValueHolder.
      E setValueDirectly​(E value)
      Sets ValueHolder vaue without triggering fault resolution.