org.eclipse.persistence.jpa.jpql.parser

Class AbstractPathExpression

java.lang.Object

org.eclipse.persistence.jpa.jpql.parser.AbstractExpression

org.eclipse.persistence.jpa.jpql.parser.AbstractPathExpression

All Implemented Interfaces:

Expression

Direct Known Subclasses:

CollectionValuedPathExpression, StateFieldPathExpression

public abstract class AbstractPathExpression
extends AbstractExpression

An identification variable followed by the navigation operator (.) and a state field or association field is a path expression. The type of the path expression is the type computed as the result of navigation; that is, the type of the state field or association field to which the expression navigates.

Since:

2.3

Version:

2.5

Author:

Pascal Filion

See Also:

CollectionValuedPathExpression, IdentificationVariable

Field Summary

Fields inherited from class org.eclipse.persistence.jpa.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.jpql.parser.Expression

ABS, ALL, AND, ANY, AS, AS_OF, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, CONNECT_BY, COUNT, CURRENT_DATE, CURRENT_TIME, CURRENT_TIMESTAMP, DELETE, DELETE_FROM, DESC, DIFFERENT, DISTINCT, DIVISION, ELSE, EMPTY, END, ENTRY, EQUAL, ESCAPE, EXCEPT, EXISTS, EXTRACT, FALSE, FETCH, FIRST, FROM, FUNC, FUNCTION, GREATER_THAN, GREATER_THAN_OR_EQUAL, GROUP_BY, HAVING, IN, INDEX, INNER, INNER_JOIN, INNER_JOIN_FETCH, INTERSECT, IS, IS_EMPTY, IS_NOT_EMPTY, IS_NOT_NULL, IS_NULL, JOIN, JOIN_FETCH, KEY, LAST, 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_EQUAL, NOT_EXISTS, NOT_IN, NOT_LIKE, NOT_MEMBER, NOT_MEMBER_OF, NULL, NULLIF, NULLS, NULLS_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, ORDER_SIBLINGS_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SCN, SELECT, SET, SIZE, SOME, SQL, SQRT, START_WITH, SUBSTRING, SUM, TABLE, THEN, TIMESTAMP, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE

Constructor Summary

Constructors

Constructor and Description
AbstractPathExpression(AbstractExpression parent, AbstractExpression identificationVariable, java.lang.String paths) Creates a new AbstractPathExpression.

Method Summary

Modifier and Type	Method and Description
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
boolean	endsWithDot() Determines whether the path ends with a dot or not.
JPQLQueryBNF	findQueryBNF(Expression expression) Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
Expression	getIdentificationVariable() Returns the identification variable that starts the path expression, which can be a sample identification variable, a map value, map key or map entry expression.
java.lang.String	getPath(int index) Returns the specified segment of the state field path.
boolean	hasIdentificationVariable() Determines whether the identification variable was parsed.
boolean	hasVirtualIdentificationVariable() Determines whether the path's identification variable is virtual or not, meaning it's not part of the query but is required for proper navigability.
ListIterable<java.lang.String>	paths() Returns the segments in the state field path in order.
int	pathSize() Returns the number of segments in the state field path.
boolean	startsWithDot() Determines whether the path starts with a dot or not.
java.lang.String	toParsedText(int startIndex, int stopIndex) Returns a string representation from the given range.

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

children, getGrammar, getIdentifierVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, isAncestor, orderedChildren, populatePosition, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.persistence.jpa.jpql.parser.Expression

accept, getQueryBNF

Constructor Detail

AbstractPathExpression

public AbstractPathExpression(AbstractExpression parent,
                              AbstractExpression identificationVariable,
                              java.lang.String paths)

Creates a new AbstractPathExpression.

Parameters:

parent - The parent of this expression

identificationVariable - The identification variable that was already parsed, which means the beginning of the parsing should start with a dot

paths - The path expression that is following the identification variable

Method Detail

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() is called.

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

Parameters:

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

endsWithDot

public final boolean endsWithDot()

Determines whether the path ends with a dot or not.

Returns:

true if the path ends with a dot; false otherwise

findQueryBNF

public final JPQLQueryBNF findQueryBNF(Expression expression)

Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.

Specified by:

findQueryBNF in interface Expression

Overrides:

findQueryBNF in class AbstractExpression

Parameters:

expression - The Expression that is a descendant of this one

Returns:

The JPQLQueryBNF that was used to parse the given expression

getIdentificationVariable

public final Expression getIdentificationVariable()

Returns the identification variable that starts the path expression, which can be a sample identification variable, a map value, map key or map entry expression.

Returns:

The root of the path expression

getPath

public final java.lang.String getPath(int index)

Returns the specified segment of the state field path.

Parameters:

index - The 0-based segment index

Returns:

The specified segment

hasIdentificationVariable

public final boolean hasIdentificationVariable()

Determines whether the identification variable was parsed.

Returns:

true the identification variable was parsed; false otherwise

hasVirtualIdentificationVariable

public final boolean hasVirtualIdentificationVariable()

Determines whether the path's identification variable is virtual or not, meaning it's not part of the query but is required for proper navigability.

Returns:

true if this identification variable was virtually created to fully qualify path expression; false if it was parsed

paths

public final ListIterable<java.lang.String> paths()

Returns the segments in the state field path in order.

Returns:

An Iterator over the segments of the state field path

pathSize

public final int pathSize()

Returns the number of segments in the state field path.

Returns:

The number of segments

startsWithDot

public final boolean startsWithDot()

Determines whether the path starts with a dot or not.

Returns:

true if the path starts with a dot; false otherwise

toParsedText

public java.lang.String toParsedText(int startIndex,
                                     int stopIndex)

Returns a string representation from the given range.

Parameters:

startIndex - The beginning of the range to create the string representation

stopIndex - When to stop creating the string representation, which is exclusive

Returns:

The string representation of this path expression contained in the given range

Since:

2.4