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

java.lang.Object
  org.eclipse.persistence.jpa.jpql.model.query.AbstractStateObject
      org.eclipse.persistence.jpa.jpql.model.query.AbstractConditionalClauseStateObject
          org.eclipse.persistence.jpa.jpql.model.query.WhenClauseStateObject

All Implemented Interfaces:

StateObject

public class WhenClauseStateObject
extends AbstractConditionalClauseStateObject

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

BNF: when_clause ::= WHEN conditional_expression THEN scalar_expression

or

BNF: simple_when_clause ::= WHEN scalar_expression THEN scalar_expression

Version:

2.4

See Also:

WhenClause

Author:

Pascal Filion

Since:

2.4

Field Summary

static java.lang.String

THEN_STATE_OBJECT_PROPERTY Notify the StateObject representing the scalar expression that follows the THEN identifier has changed.

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

CONDITIONAL_STATE_OBJECT_PROPERTY

Constructor Summary

WhenClauseStateObject(CaseExpressionStateObject parent)
Creates a new WhenClauseStateObject.

WhenClauseStateObject(CaseExpressionStateObject parent, StateObject whenStateObject, StateObject thenStateObject)
Creates a new WhenClauseStateObject.

WhenClauseStateObject(CaseExpressionStateObject parent, java.lang.String whenJpqlFragment, java.lang.String thenJpqlFragment)
Creates a new WhenClauseStateObject.

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.
WhenClause	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 this clause.
CaseExpressionStateObject	getParent() Returns the parent of this StateObject.
StateObject	getThen() Returns the StateObject representing the scalar expression that is following the THEN identifier.
boolean	hasThen() Determines whether the StateObject representing the 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.
void	parseThen(java.lang.String jpqlFragment) Parses the given JPQL fragment, which will represent the THEN expression.
void	parseWhen(java.lang.String jpqlFragment) Parses the given JPQL fragment, which will represent the WHEN clause.
void	setExpression(WhenClause 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	setThen(StateObject thenStateObject) Sets the scalar expression to be the given StateObject.
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.AbstractConditionalClauseStateObject

andParse, getBuilder, getConditional, hasConditional, orParse, parse, setConditional, shouldEncapsulateORExpression

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, 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

THEN_STATE_OBJECT_PROPERTY

public static final java.lang.String THEN_STATE_OBJECT_PROPERTY

Notify the StateObject representing the scalar expression that follows the THEN identifier has changed.

See Also:

Constant Field Values

Constructor Detail

WhenClauseStateObject

public WhenClauseStateObject(CaseExpressionStateObject parent)

Creates a new WhenClauseStateObject.

Parameters:

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

Throws:

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

WhenClauseStateObject

public WhenClauseStateObject(CaseExpressionStateObject parent,
                             StateObject whenStateObject,
                             StateObject thenStateObject)

Creates a new WhenClauseStateObject.

Parameters:

parent - The parent of this state object

whenStateObject - The StateObject representing the conditional expression that is following the WHEN identifier

thenStateObject - The StateObject representing the scalar expression that is following the THEN identifier

Throws:

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

WhenClauseStateObject

public WhenClauseStateObject(CaseExpressionStateObject parent,
                             java.lang.String whenJpqlFragment,
                             java.lang.String thenJpqlFragment)

Creates a new WhenClauseStateObject.

Parameters:

parent - The parent of this state object

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

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

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 AbstractConditionalClauseStateObject

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

getExpression

public WhenClause 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)

getIdentifier

public java.lang.String getIdentifier()

Returns the JPQL identifier of this clause.

Specified by:

getIdentifier in class AbstractConditionalClauseStateObject

Returns:

The JPQL identifier of this conditional clause

getParent

public CaseExpressionStateObject getParent()

Returns the parent of this StateObject.

Specified by:

getParent in interface StateObject

Overrides:

getParent in class AbstractStateObject

Returns:

Returns the parent of this StateObject, which is null only when this is the root of the hierarchy

getThen

public StateObject getThen()

Returns the StateObject representing the scalar expression that is following the THEN identifier.

Returns:

Either the StateObject representing the THEN expression or null if it's not defined

hasThen

public boolean hasThen()

Determines whether the StateObject representing the scalar expression is present.

Returns:

true the 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 AbstractConditionalClauseStateObject

Parameters:

stateObject - The StateObject to compare its content to this one

Returns:

true if both object are equivalent; false otherwise

parseThen

public void parseThen(java.lang.String jpqlFragment)

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

Parameters:

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

parseWhen

public void parseWhen(java.lang.String jpqlFragment)

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

Parameters:

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

setExpression

public void setExpression(WhenClause 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 WHEN clause

setThen

public void setThen(StateObject thenStateObject)

Sets the scalar expression to be the given StateObject.

Parameters:

thenStateObject - The StateObject representing the scalar 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.

Overrides:

toTextInternal in class AbstractConditionalClauseStateObject

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