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

Class EmptyCollectionComparisonExpression

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.EmptyCollectionComparisonExpression

All Implemented Interfaces:

Expression

public final class EmptyCollectionComparisonExpression
extends AbstractExpression

This expression tests whether or not the collection designated by the collection-valued path expression is empty (i.e, has no elements).

BNF: empty_collection_comparison_expression ::= collection_valued_path_expression IS [NOT] EMPTY

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

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

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
Expression	getExpression() Returns the Expression that represents the collection-valued path expression if it was parsed.
java.lang.String	getIdentifier() Returns the identifier for this expression that may include NOT if it was parsed.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasExpression() Determines whether the expression was parsed.
boolean	hasNot() Determines whether the identifier NOT was part of the query.
boolean	hasSpaceAfterIs() Determines whether a whitespace was found after IS.

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

children, findQueryBNF, getChildren, getParent, getRoot, identifierRole, identifiers, identifierVersion, isAncestor, isIdentifier, isVirtual, orderedChildren, queryBNF, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

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.

getExpression

public Expression getExpression()

Returns the Expression that represents the collection-valued path expression if it was parsed.

Returns:

The expression that was parsed representing the collection valued path expression

getIdentifier

public java.lang.String getIdentifier()

Returns the identifier for this expression that may include NOT if it was parsed. The identifier IS should always be part of the identifier but it is possible it is not present when this expression is invalid.

Returns:

Either IS NOT EMPTY, NOT EMPTY, IS EMPTY or EMPTY

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

hasExpression

public boolean hasExpression()

Determines whether the expression was parsed.

Returns:

true if the expression was parsed; false otherwise

hasNot

public boolean hasNot()

Determines whether the identifier NOT was part of the query.

Returns:

true if the identifier NOT was parsed; false otherwise

hasSpaceAfterIs

public boolean hasSpaceAfterIs()

Determines whether a whitespace was found after IS.

Returns:

true if there was a whitespace after IS; false otherwise