Module org.apache.jena.core
Package org.apache.jena.enhanced

Class Polymorphic<T>

java.lang.Object
org.apache.jena.enhanced.Polymorphic<T>
Direct Known Subclasses:
EnhNode
public abstract class Polymorphic<T> extends Object
Abstract base class for all polymorphic RDF objects, especially enhanced node and enhanced graph.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addView(Polymorphic<T> other)
    add another view for this object.
    abstract boolean
    equals(Object o)
     
    abstract int
    hashCode()
     
    abstract boolean
    isValid()
    answer true iff this enhanced node is still underpinned in the graph by triples appropriate to its type.
    <X extends T>
    boolean
    supports(Class<X> t)
    return _true_ iff this polymorphic object supports the specified interface.

    Methods inherited from class java.lang.Object

    getClass, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • supports

      public <X extends T> boolean supports(Class<X> t)
      return _true_ iff this polymorphic object supports the specified interface. Synonymous with "does the argument class have this as an instance". Actually it shouldn't be. Review.

    • isValid

      public abstract boolean isValid()
      answer true iff this enhanced node is still underpinned in the graph by triples appropriate to its type.

    • equals

      public abstract boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public abstract int hashCode()
      Overrides:
      hashCode in class Object

    • addView

      public void addView(Polymorphic<T> other)
      add another view for this object. other must be freshly constructed. To be called by subclasses when they have constructed a new view for this object.

      The method is synchronised because addView is an update operation that may happen in a read context (because of .as()). Synchronising it ensures that simultaneous updates don't end up leaving the rings in an inconsistent state. (It's not clear whether this would actually lead to any problems; it's hard to write tests to expose these issues.) This method is public ONLY so that it can be tested. TODO find a better way to make it testable.