javax.persistence.criteria
Interface Expression<T>

Type Parameters:

T - the type of the expression

All Superinterfaces:

ResultItem<T>, Selection<T>

All Known Subinterfaces:

AbstractCollectionJoin<Z,C,E>, CollectionJoin<Z,E>, From<Z,X>, Join<Z,X>, ListJoin<Z,E>, MapJoin<Z,K,V>, Parameter<T>, Path<X>, Predicate, QueryBuilder.Case<R>, QueryBuilder.Coalesce<T>, QueryBuilder.In<T>, QueryBuilder.SimpleCase<C,R>, Root<X>, SetJoin<Z,E>, Subquery<T>

public interface Expression<T>
extends Selection<T>

Type for query expressions.

Method Summary

<X> Expression<X>	as(java.lang.Class<X> type) Perform a typecast upon the expression.
java.lang.Class<T>	getJavaType() Return the Java type of the expression.
Predicate	in(java.lang.Object... values) Apply a predicate to test whether the expression is a member of the argument list.
Predicate	isNotNull() Apply a predicate to test whether the expression is not null.
Predicate	isNull() Apply a predicate to test whether the expression is null.

Methods inherited from interface javax.persistence.criteria.Selection

setAlias

Methods inherited from interface javax.persistence.ResultItem

getAlias

Method Detail

getJavaType

java.lang.Class<T> getJavaType()

Return the Java type of the expression.

Specified by:

getJavaType in interface ResultItem<T>

Returns:

the Java type of the expression

isNull

Predicate isNull()

Apply a predicate to test whether the expression is null.

Returns:

predicate testing whether the expression is null

isNotNull

Predicate isNotNull()

Apply a predicate to test whether the expression is not null.

Returns:

predicate testing whether the expression is not null.

in

Predicate in(java.lang.Object... values)

Apply a predicate to test whether the expression is a member of the argument list.

Parameters:

values -

Returns:

predicate testing for membership in the list

as

<X> Expression<X> as(java.lang.Class<X> type)

Perform a typecast upon the expression. Warning: may result in a runtime failure.

Parameters:

type -

Returns:

expression