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

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.WhenClause

All Implemented Interfaces:

Expression

public final class WhenClause

extends AbstractExpression

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

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

private boolean	hasSpaceAfterThen Determines whether a whitespace was parsed after the identifier THEN.
private boolean	hasSpaceAfterWhen Determines whether a whitespace was parsed after the identifier WHEN.
private boolean	hasSpaceAfterWhenExpression Determines whether a whitespace was parsed after the conditional expression.
private boolean	hasThen Determines whether the identifier THEN was parsed.
private AbstractExpression	thenExpression The Expression representing the expression following the identifier THEN.
private AbstractExpression	whenExpression The Expression representing the conditional predicate of the clause.

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

WhenClause(AbstractExpression parent)
Creates a new WhenClause.

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.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
AbstractExpression	getThenExpression() Returns the Expression representing the expression following the identifier THEN.
AbstractExpression	getWhenExpression() Returns the Expression representing the conditional predicate of the clause.
boolean	hasSpaceAfterThen() Determines whether a whitespace was parsed after THEN.
boolean	hasSpaceAfterWhen() Determines whether a whitespace was parsed after WHEN.
boolean	hasSpaceAfterWhenExpression() Determines whether a whitespace was parsed after the conditional expression.
boolean	hasThen() Determines whether the identifier THEN was part of the query.
boolean	hasThenExpression() Determines whether the THEN expression of the query was parsed.
boolean	hasWhenExpression() Determines whether the conditional expression of the query was 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

hasSpaceAfterThen

private boolean hasSpaceAfterThen

Determines whether a whitespace was parsed after the identifier THEN.

hasSpaceAfterWhen

private boolean hasSpaceAfterWhen

Determines whether a whitespace was parsed after the identifier WHEN.

hasSpaceAfterWhenExpression

private boolean hasSpaceAfterWhenExpression

Determines whether a whitespace was parsed after the conditional expression.

hasThen

private boolean hasThen

Determines whether the identifier THEN was parsed.

thenExpression

private AbstractExpression thenExpression

The Expression representing the expression following the identifier THEN.

whenExpression

private AbstractExpression whenExpression

The Expression representing the conditional predicate of the clause.

Constructor Detail

WhenClause

WhenClause(AbstractExpression parent)

Creates a new WhenClause.

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

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

getThenExpression

public AbstractExpression getThenExpression()

Returns the Expression representing the expression following the identifier THEN.

Returns:

The expression representing the expression executed if the predicate is true

getWhenExpression

public AbstractExpression getWhenExpression()

Returns the Expression representing the conditional predicate of the clause.

Returns:

The expression following the WHEN identifier

hasSpaceAfterThen

public boolean hasSpaceAfterThen()

Determines whether a whitespace was parsed after THEN.

Returns:

true if there was a whitespace after THEN; false otherwise

hasSpaceAfterWhen

public boolean hasSpaceAfterWhen()

Determines whether a whitespace was parsed after WHEN.

Returns:

true if there was a whitespace after WHEN; false otherwise

hasSpaceAfterWhenExpression

public boolean hasSpaceAfterWhenExpression()

Determines whether a whitespace was parsed after the conditional expression.

Returns:

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

hasThen

public boolean hasThen()

Determines whether the identifier THEN was part of the query.

Returns:

true if the identifier THEN was parsed; false otherwise

hasThenExpression

public boolean hasThenExpression()

Determines whether the THEN expression of the query was parsed.

Returns:

true the THEN expression was parsed; false if nothing was parsed

hasWhenExpression

public boolean hasWhenExpression()

Determines whether the conditional expression of the query was parsed.

Returns:

true the conditional expression was parsed; false if nothing was parsed

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