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

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractListHolderStateObject<WhenClauseStateObject>
          org.eclipse.persistence.jpa.jpql.model.query.CaseExpressionStateObject

All Implemented Interfaces:

ListHolderStateObject<WhenClauseStateObject>, StateObject

public class CaseExpressionStateObject
extends AbstractListHolderStateObject<WhenClauseStateObject>

A CASE predicate is used to calculate a condition and when it's true, its THEN expression will be executed.

BNF: general_case_expression ::= CASE when_clause {when_clause}* ELSE scalar_expression END or

BNF: simple_case_expression ::= CASE case_operand simple_when_clause {simple_when_clause}* ELSE scalar_expression END

Version:

2.4

See Also:

WhenClauseStateObject, CaseExpression

Author:

Pascal Filion

Since:

2.4

Field Summary

static java.lang.String	CASE_OPERAND_STATE_OBJECT_PROPERTY Notify the StateObject representing the case operand that follows the CASE identifier has changed.
static java.lang.String	ELSE_STATE_OBJECT_PROPERTY Notify the StateObject representing the else expression that follows the ELSE identifier has changed.
static java.lang.String	WHEN_CLAUSE_STATE_OBJECT_LIST Notify the list of StateObjects representing the when clauses that follow the WHEN has changed.

Constructor Summary

CaseExpressionStateObject(StateObject parent)
Creates a new CaseExpressionStateObject.

CaseExpressionStateObject(StateObject parent, java.util.List<WhenClauseStateObject> whenClauseStateObjects, StateObject elseStateObject)
Creates a new CaseExpressionStateObject.

CaseExpressionStateObject(StateObject parent, StateObject caseOperandStateObject, java.util.List<WhenClauseStateObject> whenClauseStateObjects, StateObject elseStateObject)
Creates a new CaseExpressionStateObject.

Method Summary

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.
protected void	addProblems(java.util.List<Problem> problems) Adds to the given list the problems that were found with the current state of this StateObject, which means there are validation issues.
WhenClauseStateObject	addWhenClause() Adds a new WHEN clause.
WhenClauseStateObject	addWhenClause(StateObject whenStateObject, StateObject thenStateObject) Adds the given two StateObjects as the WHEN expression and the THEN expression of the new WHEN clause.
WhenClauseStateObject	addWhenClause(java.lang.String whenJpqlFragment, java.lang.String thenJpqlFragment) Adds the given two StateObjects as the WHEN expression and the THEN expression of the new WHEN clause.
StateObject	getCaseOperand() Returns the StateObject representing the case operand.
StateObject	getElse() Returns the StateObject representing the ELSE scalar expression.
CaseExpression	getExpression() Returns the actual parsed object if this StateObject representation of the JPQL query was created by parsing an existing JPQL query.
boolean	hasCaseOperand() Determines whether the StateObject representing the case operand is present.
boolean	hasElse() Determines whether the StateObject representing the ELSE scalar expression is present.
boolean	isEquivalent(StateObject stateObject) Determines whether the given StateObject is equivalent to this one, i.e. the information of both StateObject is the same.
protected java.lang.String	listName() Returns the name that is uniquely identifying the list.
void	parseCaseOperand(java.lang.String jpqlFragment) Parses the given JPQL fragment, which will represent the case operand.
void	parseElse(java.lang.String jpqlFragment) Parses the given JPQL fragment, which will represent the ELSE expression.
void	removeCaseOperand() Removes the case operand.
void	setCaseOperand(StateObject caseOperand) Sets the case operand to be the given StateObject.
void	setElse(StateObject elseStateObject) Sets the ELSE scalar expression to be the given StateObject.
void	setExpression(CaseExpression 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	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.model.query.AbstractListHolderStateObject

addItem, addItems, addListChangeListener, areChildrenEquivalent, canMoveDown, canMoveUp, getItem, hasItems, initialize, items, itemsSize, moveDown, moveUp, removeItem, removeItems, removeListChangeListener, toStringItems

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

acceptUnknownVisitor, acceptUnknownVisitor, 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

Methods inherited from interface org.eclipse.persistence.jpa.jpql.model.query.StateObject

addPropertyChangeListener, children, decorate, findIdentificationVariable, getDeclaration, getDecorator, getGrammar, getManagedTypeProvider, getParent, getQueryBuilder, getRoot, isDecorated, removePropertyChangeListener, setParent, toString, toText

Field Detail

CASE_OPERAND_STATE_OBJECT_PROPERTY

public static final java.lang.String CASE_OPERAND_STATE_OBJECT_PROPERTY

Notify the StateObject representing the case operand that follows the CASE identifier has changed.

See Also:

Constant Field Values

ELSE_STATE_OBJECT_PROPERTY

public static final java.lang.String ELSE_STATE_OBJECT_PROPERTY

Notify the StateObject representing the else expression that follows the ELSE identifier has changed.

See Also:

Constant Field Values

WHEN_CLAUSE_STATE_OBJECT_LIST

public static final java.lang.String WHEN_CLAUSE_STATE_OBJECT_LIST

Notify the list of StateObjects representing the when clauses that follow the WHEN has changed.

See Also:

Constant Field Values

Constructor Detail

CaseExpressionStateObject

public CaseExpressionStateObject(StateObject parent)

Creates a new CaseExpressionStateObject.

Parameters:

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

Throws:

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

CaseExpressionStateObject

public CaseExpressionStateObject(StateObject parent,
                                 java.util.List<WhenClauseStateObject> whenClauseStateObjects,
                                 StateObject elseStateObject)

Creates a new CaseExpressionStateObject.

Parameters:

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

whenClauseStateObjects - The list of WhenClauseStateObjects that are representing the WHEN clauses

elseStateObject - The StateObject representing the scalar expression that is following the ELSE identifier

Throws:

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

CaseExpressionStateObject

public CaseExpressionStateObject(StateObject parent,
                                 StateObject caseOperandStateObject,
                                 java.util.List<WhenClauseStateObject> whenClauseStateObjects,
                                 StateObject elseStateObject)

Creates a new CaseExpressionStateObject.

Parameters:

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

caseOperandStateObject - The StateObject representing the case operand that is following the CASE identifier or null if none is declared

whenClauseStateObjects - The list of WhenClauseStateObjects that are representing the WHEN clauses

elseStateObject - The StateObject representing the scalar expression that is following the ELSE identifier

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 AbstractListHolderStateObject<WhenClauseStateObject>

Parameters:

children - The list used to store the children

addProblems

protected void addProblems(java.util.List<Problem> problems)

Adds to the given list the problems that were found with the current state of this StateObject, which means there are validation issues.

Overrides:

addProblems in class AbstractStateObject

Parameters:

problems - The list to which the problems are added

addWhenClause

public WhenClauseStateObject addWhenClause()

Adds a new WHEN clause.

Returns:

The newly created WhenClauseStateObject

addWhenClause

public WhenClauseStateObject addWhenClause(StateObject whenStateObject,
                                           StateObject thenStateObject)

Adds the given two StateObjects as the WHEN expression and the THEN expression of the new WHEN clause.

Parameters:

whenStateObject - The StateObject representing the WHEN expression

thenStateObject - The StateObject representing the THEN expression

Returns:

The newly created WhenClauseStateObject

addWhenClause

public WhenClauseStateObject addWhenClause(java.lang.String whenJpqlFragment,
                                           java.lang.String thenJpqlFragment)

Adds the given two StateObjects as the WHEN expression and the THEN expression of the new WHEN clause.

Parameters:

whenJpqlFragment - The string representation of the WHEN to parse and to convert into a StateObject representation

thenJpqlFragment - The string representation of the THEN to parse and to convert into a StateObject representation

Returns:

The newly created WhenClauseStateObject

getCaseOperand

public StateObject getCaseOperand()

Returns the StateObject representing the case operand.

Returns:

The StateObject representing the case operand or null if it is not present

getElse

public StateObject getElse()

Returns the StateObject representing the ELSE scalar expression.

Returns:

The StateObject representing the ELSE scalar expression or null if it is not present

getExpression

public CaseExpression 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)

hasCaseOperand

public boolean hasCaseOperand()

Determines whether the StateObject representing the case operand is present.

Returns:

true the case operand exists; otherwise false

hasElse

public boolean hasElse()

Determines whether the StateObject representing the ELSE scalar expression is present.

Returns:

true the ELSE scalar expression exists; otherwise false

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

listName

protected java.lang.String listName()

Returns the name that is uniquely identifying the list.

Specified by:

listName in class AbstractListHolderStateObject<WhenClauseStateObject>

Returns:

The unique name identifying the list

parseCaseOperand

public void parseCaseOperand(java.lang.String jpqlFragment)

Parses the given JPQL fragment, which will represent the case operand. The JPQL fragment should not start with the identifier.

Parameters:

jpqlFragment - The string representation of the case operand to parse and to convert into a StateObject representation

parseElse

public void parseElse(java.lang.String jpqlFragment)

Parses the given JPQL fragment, which will represent the ELSE expression. The JPQL fragment should not start with the identifier.

Parameters:

jpqlFragment - The string representation of the ELSE to parse and to convert into a StateObject representation

removeCaseOperand

public void removeCaseOperand()

Removes the case operand.

setCaseOperand

public void setCaseOperand(StateObject caseOperand)

Sets the case operand to be the given StateObject.

Parameters:

caseOperand - The StateObject representing the case operand or null to remove it

setElse

public void setElse(StateObject elseStateObject)

Sets the ELSE scalar expression to be the given StateObject.

Parameters:

elseStateObject - The StateObject representing the ELSE scalar expression or null to remove it

setExpression

public void setExpression(CaseExpression 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 a CASE expression

toTextInternal

public 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