org.eclipse.persistence.jpa.internal.jpql.parser
Class CaseExpression

java.lang.Object
org.eclipse.persistence.jpa.internal.jpql.parser.StringExpression
org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression
org.eclipse.persistence.jpa.internal.jpql.parser.CaseExpression

All Implemented Interfaces:

Expression

public final class CaseExpression

extends AbstractExpression

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

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Nested Class Summary

private static class

CaseExpression.ParsingType A enumeration used to determine how CaseExpression#isParsingComplete(WordParser, String) should behaves.

Field Summary

private AbstractExpression	caseOperand The Expression representing the case operand.
private AbstractExpression	elseExpression The Expression representing the ELSE expression.
private boolean	hasElse Determines whether the identifier ELSE was parsed.
private boolean	hasEnd Determines whether the identifier END was parsed.
private boolean	hasSpaceAfterCase Determines whether a whitespace was parsed after CASE.
private boolean	hasSpaceAfterCaseOperand Determines whether a whitespace was parsed after the case operand.
private boolean	hasSpaceAfterElse Determines whether a whitespace was parsed after ELSE.
private boolean	hasSpaceAfterElseExpression Determines whether a whitespace was parsed after the BETWEEN expression.
private boolean	hasSpaceAfterWhenClauses Determines whether a whitespace was parsed after WHEN clause.
private CaseExpression.ParsingType	parsingType Used to determine how to check if the parsing is complete.
private AbstractExpression	whenClauses The Expression representing the WHEN clauses.

Fields inherited from class org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression

COMMA, DOT, DOUBLE_QUOTE, LEFT_CURLY_BRACKET, LEFT_PARENTHESIS, NOT_DEFINED, RIGHT_CURLY_BRACKET, RIGHT_PARENTHESIS, SINGLE_QUOTE, SPACE, UNDERSCORE

Fields inherited from interface org.eclipse.persistence.jpa.internal.jpql.parser.Expression

ABS, ALL, AND, ANY, AS, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, CONCAT, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXISTS, FALSE, FETCH, FROM, FUNC, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LEADING, LEFT, LEFT_JOIN, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN, LEFT_OUTER_JOIN_FETCH, LENGTH, LIKE, LOCATE, LOWER, LOWER_THAN, LOWER_THAN_OR_EQUAL, MAX, MEMBER, MEMBER_OF, MIN, MINUS, MOD, MULTIPLICATION, NAMED_PARAMETER, NEW, NOT, NOT_BETWEEN, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, OBJECT, OF, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, SELECT, SET, SIZE, SOME, SQRT, SUBSTRING, SUM, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

CaseExpression(AbstractExpression parent)
Creates a new CaseExpression.

Method Summary

void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
(package private) void	addChildrenTo(java.util.Collection<Expression> children) Adds the children of this Expression to the given collection.
(package private) void	addOrderedChildrenTo(java.util.List<StringExpression> children) Adds the StringExpressions representing this Expression.
Expression	getCaseOperand() Returns the Expression that represents the CASE operand.
AbstractExpression	getElseExpression() Returns the Expression that represents the ELSE operand.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
AbstractExpression	getWhenClauses() Returns the Expression that represents the WHEN clauses.
boolean	hasCaseOperand() Determines whether the CASE operand was parsed.
boolean	hasElse() Determines whether the identifier ELSE was parsed.
boolean	hasElseExpression() Determines whether the ELSE expression was parsed.
boolean	hasEnd() Determines whether the identifier END was parsed.
boolean	hasSpaceAfterCase() Determines whether a whitespace was parsed after CASE.
boolean	hasSpaceAfterCaseOperand() Determines whether a whitespace was parsed after the case operand.
boolean	hasSpaceAfterElse() Determines whether a whitespace was parsed after ELSE.
boolean	hasSpaceAfterElseExpression() Determines whether a whitespace was parsed after the else expression.
boolean	hasSpaceAfterWhenClauses() Determines whether a whitespace was parsed after the WHEN clause.
boolean	hasWhenClauses() Determines whether the WHEN clauses were parsed.
(package private) boolean	isParsingComplete(WordParser wordParser, java.lang.String word, Expression expression) Determines whether the parsing is complete based on what is left in the given text.
(package private) void	parse(WordParser wordParser, boolean tolerant) Parses the query by starting at the current position, which is part of the given WordParser.
(package private) void	toParsedText(java.lang.StringBuilder writer, boolean includeVirtual) Generates a string representation of this Expression.

Methods inherited from class org.eclipse.persistence.jpa.internal.jpql.parser.AbstractExpression

buildExpressionFromFallingBack, buildNullExpression, buildStringExpression, buildStringExpression, buildUnknownExpression, children, expressionFactory, expressionFactoryForIdentifier, findQueryBNF, getChildren, getJPAVersion, getParent, getRoot, getText, handleAggregate, identifierRole, identifiers, identifiers, identifierVersion, isAncestor, isIdentifier, isNull, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseSingleExpression, populatePosition, queryBNF, readdLeadingSpaces, rebuildActualText, rebuildParsedText, setParent, setText, shouldParseWithFactoryFirst, shouldSkipLiteral, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

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

Field Detail

caseOperand

private AbstractExpression caseOperand

The Expression representing the case operand.

elseExpression

private AbstractExpression elseExpression

The Expression representing the ELSE expression.

hasElse

private boolean hasElse

Determines whether the identifier ELSE was parsed.

hasEnd

private boolean hasEnd

Determines whether the identifier END was parsed.

hasSpaceAfterCase

private boolean hasSpaceAfterCase

Determines whether a whitespace was parsed after CASE.

hasSpaceAfterCaseOperand

private boolean hasSpaceAfterCaseOperand

Determines whether a whitespace was parsed after the case operand.

hasSpaceAfterElse

private boolean hasSpaceAfterElse

Determines whether a whitespace was parsed after ELSE.

hasSpaceAfterElseExpression

private boolean hasSpaceAfterElseExpression

Determines whether a whitespace was parsed after the BETWEEN expression.

hasSpaceAfterWhenClauses

private boolean hasSpaceAfterWhenClauses

Determines whether a whitespace was parsed after WHEN clause.

parsingType

private CaseExpression.ParsingType parsingType

Used to determine how to check if the parsing is complete.

whenClauses

private AbstractExpression whenClauses

The Expression representing the WHEN clauses.

Constructor Detail

CaseExpression

CaseExpression(AbstractExpression parent)

Creates a new CaseExpression.

Parameters:

parent - The parent of this expression

Method Detail

accept

public void accept(ExpressionVisitor visitor)

Visits this Expression by the given visitor.

Parameters:

visitor - The visitor to visit this object

acceptChildren

public void acceptChildren(ExpressionVisitor visitor)

Visits the children of this Expression. This method can be used to optimize traversing the children since a new list is not created every time Expression.children() or Expression.getChildren() is called.

This does not traverse the Expression sub-hierarchy, use an subclass of AbstractTraverseChildrenVisitor in order to traverse the entire sub-hierarchy.

Parameters:

visitor - The visitor to visit the children of this object.

addChildrenTo

void addChildrenTo(java.util.Collection<Expression> children)

Adds the children of this Expression to the given collection.

Overrides:

addChildrenTo in class AbstractExpression

Parameters:

children - The collection used to store the children

addOrderedChildrenTo

void addOrderedChildrenTo(java.util.List<StringExpression> children)

Adds the StringExpressions representing this Expression.

Overrides:

addOrderedChildrenTo in class AbstractExpression

Parameters:

children - The list used to store the string representation of this Expression

getCaseOperand

public Expression getCaseOperand()

Returns the Expression that represents the CASE operand.

Returns:

The expression that was parsed representing the CASE operand

getElseExpression

public AbstractExpression getElseExpression()

Returns the Expression that represents the ELSE operand.

Returns:

The expression that was parsed representing the ELSE operand

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Specified by:

getQueryBNF in class AbstractExpression

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

getWhenClauses

public AbstractExpression getWhenClauses()

Returns the Expression that represents the WHEN clauses.

Returns:

The expression that was parsed representing the WHEN clauses

hasCaseOperand

public boolean hasCaseOperand()

Determines whether the CASE operand was parsed.

Returns:

true if the CASE operand was parsed; false otherwise

hasElse

public boolean hasElse()

Determines whether the identifier ELSE was parsed.

Returns:

true if the identifier ELSE was parsed; false otherwise

hasElseExpression

public boolean hasElseExpression()

Determines whether the ELSE expression was parsed.

Returns:

true if the ELSE expression was parsed; false otherwise

hasEnd

public boolean hasEnd()

Determines whether the identifier END was parsed.

Returns:

true if the identifier END was parsed; false otherwise

hasSpaceAfterCase

public boolean hasSpaceAfterCase()

Determines whether a whitespace was parsed after CASE.

Returns:

true if there was a whitespace after CASE; false otherwise

hasSpaceAfterCaseOperand

public boolean hasSpaceAfterCaseOperand()

Determines whether a whitespace was parsed after the case operand.

Returns:

true if there was a whitespace after the case operand; false otherwise

hasSpaceAfterElse

public boolean hasSpaceAfterElse()

Determines whether a whitespace was parsed after ELSE.

Returns:

true if there was a whitespace after ELSE; false otherwise

hasSpaceAfterElseExpression

public boolean hasSpaceAfterElseExpression()

Determines whether a whitespace was parsed after the else expression.

Returns:

true if there was a whitespace after the else expression; false otherwise

hasSpaceAfterWhenClauses

public boolean hasSpaceAfterWhenClauses()

Determines whether a whitespace was parsed after the WHEN clause.

Returns:

true if there was a whitespace after <the b>WHEN clause; false otherwise

hasWhenClauses

public boolean hasWhenClauses()

Determines whether the WHEN clauses were parsed.

Returns:

true if the WHEN clauses were parsed; false otherwise

isParsingComplete

boolean isParsingComplete(WordParser wordParser,
                          java.lang.String word,
                          Expression expression)

Determines whether the parsing is complete based on what is left in the given text. The text is never empty.

Overrides:

isParsingComplete in class AbstractExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

word - The word that was retrieved from the given text, which is the first word in the text

expression - The Expression that has already been parsed

Returns:

true if the text no longer can't be parsed by the current expression; false if more can be parsed

parse

void parse(WordParser wordParser,
           boolean tolerant)

Parses the query by starting at the current position, which is part of the given WordParser.

Specified by:

parse in class AbstractExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

tolerant - Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries

toParsedText

void toParsedText(java.lang.StringBuilder writer,
                  boolean includeVirtual)

Generates a string representation of this Expression.

Specified by:

toParsedText in class AbstractExpression

Parameters:

writer - The buffer used to append this Expression's string representation

includeVirtual - Determines whether to include any characters that are considered virtual, i.e. that was parsed when the query is incomplete and is needed for functionality like content assist