Package org.dellroad.querystream.jpa

Interface Ref<X,S extends Selection<X>>

Type Parameters:
X - stream item type
S - criteria type for stream item
All Known Implementing Classes:
ExprRef, FromRef, PathRef, RootRef
public interface Ref<X,S extends Selection<X>>
A reference to items in a QueryStream.

Refs are created and then bound to the items in a QueryStream via QueryStream.bind(). Once bound, they may be accessed in a subsequent filter predicate, subquery QueryStream, etc., via get().

  • Method Summary

    Modifier and Type
    Method
    Description
    S
    bind(S value)
    Bind the given value to this reference.
    S
    get()
    Get the bound value.
    boolean
    isBound()
    Determine if this instance is bound.
    void
    unbind()
    Unbind the bound value, if any.

  • Method Details

    • bind

      S bind(S value)
      Bind the given value to this reference.
      Parameters:
      value - value to bind
      Returns:
      same value
      Throws:
      IllegalStateException - if another value is already bound
      IllegalArgumentException - if value is null

    • get

      S get()
      Get the bound value.
      Returns:
      bound value
      Throws:
      IllegalStateException - if this instance is not bound

    • unbind

      void unbind()
      Unbind the bound value, if any.

    • isBound

      boolean isBound()
      Determine if this instance is bound.
      Returns:
      true if this instance is bound, otherwise false