org.eclipse.persistence.jpa.jpql.model.query
Class ExistsExpressionStateObject

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractEncapsulatedExpressionStateObject
          org.eclipse.persistence.jpa.jpql.model.query.AbstractSingleEncapsulatedExpressionStateObject
              org.eclipse.persistence.jpa.jpql.model.query.ExistsExpressionStateObject

All Implemented Interfaces:

StateObject

public class ExistsExpressionStateObject
extends AbstractSingleEncapsulatedExpressionStateObject

An EXISTS expression is a predicate that is true only if the result of the subquery consists of one or more values and that is false otherwise.

BNF: exists_expression ::= [NOT] EXISTS(subquery)

Version:

2.4

See Also:

ExistsExpression

Author:

Pascal Filion

Since:

2.4

Field Summary

static java.lang.String

NOT_PROPERTY Notifies the visibility of the NOT identifier has changed.

Fields inherited from class org.eclipse.persistence.jpa.jpql.model.query.AbstractSingleEncapsulatedExpressionStateObject

STATE_OBJECT_PROPERTY

Constructor Summary

ExistsExpressionStateObject(StateObject parent)
Creates a new ExistsExpressionStateObject.

ExistsExpressionStateObject(StateObject parent, boolean not, StateObject stateObject)
Creates a new ExistsExpressionStateObject.

ExistsExpressionStateObject(StateObject parent, boolean not, java.lang.String jpqlFragment)
Creates a new ExistsExpressionStateObject.

ExistsExpressionStateObject(StateObject parent, StateObject stateObject)
Creates a new ExistsExpressionStateObject.

ExistsExpressionStateObject(StateObject parent, java.lang.String jpqlFragment)
Creates a new ExistsExpressionStateObject.

Method Summary

void	accept(StateObjectVisitor visitor) Visits this StateObject by the given visitor.
ExistsExpressionStateObject	addNot() Makes sure the NOT identifier is specified.
ExistsExpression	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
java.lang.String	getIdentifier() Returns the JPQL identifier of the expression represented by this AbstractSingleEncapsulatedExpressionStateObject.
protected java.lang.String	getQueryBNFId() Returns the unique identifier of the JPQLQueryBNF that will determine how to parse the encapsulated expression.
boolean	hasNot() Determines whether the NOT identifier is used or not.
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(ExistsExpression 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	setStateObject(StateObject stateObject) Sets the given StateObject to represent the new encapsulated expression.
void	toggleNot() Changes the visibility state of the NOT identifier.
protected void	toTextEncapsulatedExpression(java.lang.Appendable writer) Prints out a string representation of this encapsulated information, 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.model.query.AbstractSingleEncapsulatedExpressionStateObject

addChildren, getStateObject, hasStateObject, parse

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

toTextInternal

Methods inherited from class org.eclipse.persistence.jpa.jpql.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, initialize, 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 java.lang.String NOT_PROPERTY

Notifies the visibility of the NOT identifier has changed.

Constructor Detail

ExistsExpressionStateObject

public ExistsExpressionStateObject(StateObject parent)

Creates a new ExistsExpressionStateObject.

Parameters:

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

Throws:

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

ExistsExpressionStateObject

public ExistsExpressionStateObject(StateObject parent,
                                   boolean not,
                                   StateObject stateObject)

Creates a new ExistsExpressionStateObject.

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

stateObject - The StateObject representing the subquery

Throws:

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

ExistsExpressionStateObject

public ExistsExpressionStateObject(StateObject parent,
                                   boolean not,
                                   java.lang.String jpqlFragment)

Creates a new ExistsExpressionStateObject.

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

jpqlFragment - The portion of the query representing the encapsulated expression

Throws:

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

ExistsExpressionStateObject

public ExistsExpressionStateObject(StateObject parent,
                                   StateObject stateObject)

Creates a new ExistsExpressionStateObject.

Parameters:

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

stateObject - The StateObject representing the subquery

Throws:

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

ExistsExpressionStateObject

public ExistsExpressionStateObject(StateObject parent,
                                   java.lang.String jpqlFragment)

Creates a new ExistsExpressionStateObject.

Parameters:

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

jpqlFragment - The portion of the query representing the encapsulated 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

addNot

public ExistsExpressionStateObject addNot()

Makes sure the NOT identifier is specified.

Returns:

This object

getExpression

public ExistsExpression 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 AbstractSingleEncapsulatedExpressionStateObject

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)

getIdentifier

public java.lang.String getIdentifier()

Returns the JPQL identifier of the expression represented by this AbstractSingleEncapsulatedExpressionStateObject.

Specified by:

getIdentifier in class AbstractEncapsulatedExpressionStateObject

Returns:

The JPQL identifier that is shown before the left parenthesis

getQueryBNFId

protected java.lang.String getQueryBNFId()

Returns the unique identifier of the JPQLQueryBNF that will determine how to parse the encapsulated expression.

Specified by:

getQueryBNFId in class AbstractSingleEncapsulatedExpressionStateObject

Returns:

The non-null ID of the BNF

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

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 AbstractSingleEncapsulatedExpressionStateObject

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(ExistsExpression 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 EXISTS 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

setStateObject

public void setStateObject(StateObject stateObject)

Sets the given StateObject to represent the new encapsulated expression.

Overrides:

setStateObject in class AbstractSingleEncapsulatedExpressionStateObject

Parameters:

stateObject - The new encapsulated StateObject

toggleNot

public void toggleNot()

Changes the visibility state of the NOT identifier.

toTextEncapsulatedExpression

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

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

Overrides:

toTextEncapsulatedExpression in class AbstractSingleEncapsulatedExpressionStateObject

Parameters:

writer - The writer used to print out the string representation of the encapsulated information

Throws:

java.io.IOException - This should never happens, only required because Appendable is used instead of StringBuilder for instance