org.apache.openjpa.persistence.criteria

Class Expressions.IsEmpty

java.lang.Object

org.apache.openjpa.persistence.criteria.SelectionImpl<X>

org.apache.openjpa.persistence.criteria.ExpressionImpl<Boolean>

org.apache.openjpa.persistence.criteria.PredicateImpl

org.apache.openjpa.persistence.criteria.Expressions.IsEmpty

All Implemented Interfaces:

javax.persistence.criteria.Expression<Boolean>, javax.persistence.criteria.Predicate, javax.persistence.criteria.Selection<Boolean>, javax.persistence.TupleElement<Boolean>, CriteriaExpression

Enclosing class:

Expressions

public static class Expressions.IsEmpty
extends PredicateImpl

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.openjpa.persistence.criteria.PredicateImpl

PredicateImpl.And, PredicateImpl.Or

Nested classes/interfaces inherited from interface javax.persistence.criteria.Predicate

javax.persistence.criteria.Predicate.BooleanOperator

Field Summary

Fields

Modifier and Type	Field and Description
(package private) ExpressionImpl<?>	collection

Fields inherited from class org.apache.openjpa.persistence.criteria.PredicateImpl

_exps

Constructor Summary

Constructors

Constructor and Description
Expressions.IsEmpty(javax.persistence.criteria.Expression<?> collection)

Method Summary

Methods

Modifier and Type	Method and Description
void	acceptVisit(CriteriaExpressionVisitor visitor) Accept visit from the given visitor.
StringBuilder	asValue(AliasContext q) Get a string representation of this node as a value in the context of the given query.
PredicateImpl	not() Returns a new predicate as the negation of this predicate.
(package private) Expression	toKernelExpression(ExpressionFactory factory, CriteriaQueryImpl<?> q) Bridge contract to convert this facade expression to a kernel expression.
(package private) Value	toValue(ExpressionFactory factory, CriteriaQueryImpl<?> q) Bridge contract to convert this facade expression to a kernel value.

Methods inherited from class org.apache.openjpa.persistence.criteria.PredicateImpl

add, FALSE, getExpressions, getOperator, isEmpty, isNegated, markNegated, TRUE

Methods inherited from class org.apache.openjpa.persistence.criteria.ExpressionImpl

as, in, in, in, in, isNotNull, isNull

Methods inherited from class org.apache.openjpa.persistence.criteria.SelectionImpl

alias, asProjection, assertValidName, asVariable, getAlias, getCompoundSelectionItems, getJavaType, isAliased, isAutoAliased, isCompoundSelection, setAutoAlias

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface javax.persistence.criteria.Expression

as, in, in, in, in, isNotNull, isNull

Methods inherited from interface javax.persistence.criteria.Selection

alias, getCompoundSelectionItems, isCompoundSelection

Methods inherited from interface javax.persistence.TupleElement

getAlias, getJavaType

Field Detail

collection

final ExpressionImpl<?> collection

Constructor Detail

Expressions.IsEmpty

public Expressions.IsEmpty(javax.persistence.criteria.Expression<?> collection)

Method Detail

not

public PredicateImpl not()

Description copied from class: PredicateImpl

Returns a new predicate as the negation of this predicate.
Note: Default negation creates a Not expression with this receiver as delegate. Derived predicates can return the inverse expression, if exists. For example, NotEqual for Equal or LessThan for GreaterThanEqual etc.

Specified by:

not in interface javax.persistence.criteria.Predicate

Overrides:

not in class PredicateImpl

toValue

Value toValue(ExpressionFactory factory,
            CriteriaQueryImpl<?> q)

Description copied from class: ExpressionImpl

Bridge contract to convert this facade expression to a kernel value.

Overrides:

toValue in class PredicateImpl

Parameters:

factory - creates the kernel expression

q - the query definition context of this expression

Returns:

an equivalent kernel value

toKernelExpression

Expression toKernelExpression(ExpressionFactory factory,
                            CriteriaQueryImpl<?> q)

Description copied from class: ExpressionImpl

Bridge contract to convert this facade expression to a kernel expression.

Overrides:

toKernelExpression in class PredicateImpl

Parameters:

factory - creates the kernel expression

q - the query definition context of this expression

Returns:

an equivalent kernel expression

acceptVisit

public void acceptVisit(CriteriaExpressionVisitor visitor)

Description copied from interface: CriteriaExpression

Accept visit from the given visitor. The receiver is responsible to propagate the visitor to the constituent sub-nodes if any.

Specified by:

acceptVisit in interface CriteriaExpression

Overrides:

acceptVisit in class PredicateImpl

Parameters:

visitor - a processor to walk the nodes of a tree.

asValue

public StringBuilder asValue(AliasContext q)

Description copied from interface: CriteriaExpression

Get a string representation of this node as a value in the context of the given query.

Specified by:

asValue in interface CriteriaExpression

Overrides:

asValue in class PredicateImpl