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 and 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 Detail

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