Package org.eclipse.persistence.jpa.jpql.tools.model.query

Class EmptyCollectionComparisonExpressionStateObject

java.lang.Object

org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractStateObject

org.eclipse.persistence.jpa.jpql.tools.model.query.EmptyCollectionComparisonExpressionStateObject

All Implemented Interfaces:

StateObject

public class EmptyCollectionComparisonExpressionStateObject
extends AbstractStateObject

This expression tests whether or not the collection designated by the collection-valued path expression is empty (i.e, has no elements).

BNF: empty_collection_comparison_expression ::= collection_valued_path_expression IS [NOT] EMPTY

Version:

2.4

See Also:

EmptyCollectionComparisonExpression

Author:

Pascal Filion

Since:

2.4

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	NOT_PROPERTY	Notifies the visibility of the NOT identifier has changed.

Constructor Summary

Constructors

Constructor	Description
EmptyCollectionComparisonExpressionStateObject(StateObject parent)	Creates a new EmptyCollectionComparisonExpressionStateObject.
EmptyCollectionComparisonExpressionStateObject(StateObject parent, boolean not, java.lang.String path)	Creates a new EmptyCollectionComparisonExpressionStateObject.
EmptyCollectionComparisonExpressionStateObject(StateObject parent, java.lang.String path)	Creates a new EmptyCollectionComparisonExpressionStateObject.

Method Summary

Modifier and Type	Method	Description
void	accept(StateObjectVisitor visitor)	Visits this StateObject by the given visitor.
protected void	addChildren(java.util.List<StateObject> children)	Adds the children of this StateObject to the given list.
EmptyCollectionComparisonExpressionStateObject	addNot()	Makes sure the NOT identifier is specified.
EmptyCollectionComparisonExpression	getExpression()	Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
CollectionValuedPathExpressionStateObject	getStateObject()	Returns the CollectionValuedPathExpressionStateObject representing the collection- valued path expression.
boolean	hasNot()	Determines whether the NOT identifier is used or not.
protected void	initialize()	Initializes this state object.
boolean	isEquivalent(StateObject stateObject)	Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.
void	removeNot()	Makes sure the NOT identifier is not specified.
void	setExpression(EmptyCollectionComparisonExpression expression)	Keeps a reference of the parsed object object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query into StateObjects.
void	setNot(boolean not)	Sets whether the NOT identifier should be part of the expression or not.
void	toggleNot()	Changes the visibility state of the NOT identifier.
protected void	toTextInternal(java.lang.Appendable writer)	Prints out a string representation of this StateObject, which should not be used to define a true string representation of a JPQL query but should be used for debugging purposes.

Methods inherited from class org.eclipse.persistence.jpa.jpql.tools.model.query.AbstractStateObject

acceptUnknownVisitor, acceptUnknownVisitor, addProblems, addPropertyChangeListener, areEquivalent, buildProblem, buildProblem, buildStateObject, buildStateObjects, checkParent, children, decorate, equals, findIdentificationVariable, firePropertyChanged, getChangeSupport, getDeclaration, getDecorator, getGrammar, getManagedTypeProvider, getParent, getQueryBuilder, getRoot, getType, getType, getTypeHelper, getTypeRepository, hashCode, isDecorated, parent, parent, parent, removePropertyChangeListener, setExpression, setParent, toString, toString, toStringInternal, toStringItems, toText

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

NOT_PROPERTY

public static final java.lang.String NOT_PROPERTY

Notifies the visibility of the NOT identifier has changed.

See Also:

Constant Field Values

Constructor Detail

EmptyCollectionComparisonExpressionStateObject

public EmptyCollectionComparisonExpressionStateObject(StateObject parent)

Creates a new EmptyCollectionComparisonExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

Throws:

java.lang.NullPointerException - The given parent cannot be null

EmptyCollectionComparisonExpressionStateObject

public EmptyCollectionComparisonExpressionStateObject(StateObject parent,
                                                      boolean not,
                                                      java.lang.String path)

Creates a new EmptyCollectionComparisonExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

not - Determines whether the NOT identifier is part of the expression or not

path - The collection-valued path expression

Throws:

java.lang.NullPointerException - The given parent cannot be null

EmptyCollectionComparisonExpressionStateObject

public EmptyCollectionComparisonExpressionStateObject(StateObject parent,
                                                      java.lang.String path)

Creates a new EmptyCollectionComparisonExpressionStateObject.

Parameters:

parent - The parent of this state object, which cannot be null

path - The collection-valued path expression

Throws:

java.lang.NullPointerException - The given parent cannot be null

Method Detail

accept

public void accept(StateObjectVisitor visitor)

Visits this StateObject by the given visitor.

Parameters:

visitor - The visitor to visit this object

addChildren

protected void addChildren(java.util.List<StateObject> children)

Adds the children of this StateObject to the given list.

Overrides:

addChildren in class AbstractStateObject

Parameters:

children - The list used to store the children

addNot

public EmptyCollectionComparisonExpressionStateObject addNot()

Makes sure the NOT identifier is specified.

Returns:

This object

getExpression

public EmptyCollectionComparisonExpression getExpression()

Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.

Specified by:

getExpression in interface StateObject

Overrides:

getExpression in class AbstractStateObject

Returns:

The parsed object when a JPQL query is parsed and converted into a StateObject or null when the JPQL query is manually created (i.e. not from a string)

getStateObject

public CollectionValuedPathExpressionStateObject getStateObject()

Returns the CollectionValuedPathExpressionStateObject representing the collection- valued path expression.

Returns:

The CollectionValuedPathExpressionStateObject representing the collection- valued path expression, which is never null

hasNot

public boolean hasNot()

Determines whether the NOT identifier is used or not.

Returns:

true if the NOT identifier is part of the expression; false otherwise

initialize

protected void initialize()

Initializes this state object.

Overrides:

initialize in class AbstractStateObject

isEquivalent

public boolean isEquivalent(StateObject stateObject)

Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.

Specified by:

isEquivalent in interface StateObject

Overrides:

isEquivalent in class AbstractStateObject

Parameters:

stateObject - The StateObject to compare its content to this one

Returns:

true if both object are equivalent; false otherwise

removeNot

public void removeNot()

Makes sure the NOT identifier is not specified.

setExpression

public void setExpression(EmptyCollectionComparisonExpression expression)

Keeps a reference of the parsed object object, which should only be done when this object is instantiated during the conversion of a parsed JPQL query into StateObjects.

Parameters:

expression - The parsed object representing an EMPTY expression

setNot

public void setNot(boolean not)

Sets whether the NOT identifier should be part of the expression or not.

Parameters:

not - true if the NOT identifier should be part of the expression; false otherwise

toggleNot

public void toggleNot()

Changes the visibility state of the NOT identifier.

toTextInternal

protected void toTextInternal(java.lang.Appendable writer)
                       throws java.io.IOException

Prints out a string representation of this StateObject, which should not be used to define a true string representation of a JPQL query but should be used for debugging purposes.

Specified by:

toTextInternal in class AbstractStateObject

Parameters:

writer - The writer used to print out the string representation

Throws:

java.io.IOException - This should never happens, it is only required because Appendable is used instead of any concrete class