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

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.Join

All Implemented Interfaces:

Expression

public final class Join

extends AbstractExpression

A JOIN enables the fetching of an association as a side effect of the execution of a query. A JOIN is specified over an entity and its related entities.

BNF: join ::= join_spec join_association_path_expression [AS] identification_variable

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

private boolean	hasAs Determines whether the identifier AS was parsed.
private boolean	hasSpaceAfterAs Determines whether a whitespace was parsed after AS.
private boolean	hasSpaceAfterJoin Determines whether a whitespace was parsed after JOIN.
private boolean	hasSpaceAfterJoinAssociation Determines whether a whitespace was parsed after the join association path expression.
private AbstractExpression	identificationVariable The Expression representing the identification variable.
private AbstractExpression	joinAssociationPath The Expression representing the join association path expression.

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

Join(AbstractExpression parent, java.lang.String identifier)
Creates a new Join.

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	getIdentificationVariable() Returns the Expression that represents the identification variable.
java.lang.String	getIdentifier() Returns the identifier this expression represents.
Expression	getJoinAssociationPath() Returns the Expression that represents the join association path expression.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasAs() Determines whether the identifier AS was parsed.
boolean	hasIdentificationVariable() Determines whether the identification variable was parsed.
boolean	hasJoinAssociationPath() Determines whether the join association path expression was parsed.
boolean	hasSpaceAfterAs() Determines whether a whitespace was parsed after AS.
boolean	hasSpaceAfterJoin() Determines whether a whitespace was parsed after JOIN.
boolean	hasSpaceAfterJoinAssociation() Determines whether a whitespace was parsed after the join association path expression.
boolean	isLeftJoin() Determines whether this Join is a left join, i.e.
(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

hasAs

private boolean hasAs

Determines whether the identifier AS was parsed.

hasSpaceAfterAs

private boolean hasSpaceAfterAs

Determines whether a whitespace was parsed after AS.

hasSpaceAfterJoin

private boolean hasSpaceAfterJoin

Determines whether a whitespace was parsed after JOIN.

hasSpaceAfterJoinAssociation

private boolean hasSpaceAfterJoinAssociation

Determines whether a whitespace was parsed after the join association path expression.

identificationVariable

private AbstractExpression identificationVariable

The Expression representing the identification variable.

joinAssociationPath

private AbstractExpression joinAssociationPath

The Expression representing the join association path expression.

Constructor Detail

Join

Join(AbstractExpression parent,
     java.lang.String identifier)

Creates a new Join.

Parameters:

parent - The parent of this expression

identifier - The full JOIN identifier

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

getIdentificationVariable

public Expression getIdentificationVariable()

Returns the Expression that represents the identification variable.

Returns:

The expression that was parsed representing the identification variable

getIdentifier

public java.lang.String getIdentifier()

Returns the identifier this expression represents.

Returns:

Either JOIN, INNER JOIN, LEFT JOIN or LEFT OUTER JOIN. Although it's possible to have an incomplete identifier if the query is not complete

getJoinAssociationPath

public Expression getJoinAssociationPath()

Returns the Expression that represents the join association path expression.

Returns:

The expression that was parsed representing the join association path 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

hasAs

public boolean hasAs()

Determines whether the identifier AS was parsed.

Returns:

true if the identifier AS was parsed; false otherwise

hasIdentificationVariable

public boolean hasIdentificationVariable()

Determines whether the identification variable was parsed.

Returns:

true if the identification variable was parsed; false otherwise

hasJoinAssociationPath

public boolean hasJoinAssociationPath()

Determines whether the join association path expression was parsed.

Returns:

true if the join association path expression was parsed; false otherwise

hasSpaceAfterAs

public boolean hasSpaceAfterAs()

Determines whether a whitespace was parsed after AS.

Returns:

true if there was a whitespace after AS; false otherwise

hasSpaceAfterJoin

public boolean hasSpaceAfterJoin()

Determines whether a whitespace was parsed after JOIN.

Returns:

true if there was a whitespace after JOIN; false otherwise

hasSpaceAfterJoinAssociation

public boolean hasSpaceAfterJoinAssociation()

Determines whether a whitespace was parsed after the join association path expression.

Returns:

true if there was a whitespace after join association path expression; false otherwise

isLeftJoin

public boolean isLeftJoin()

Determines whether this Join is a left join, i.e. Expression.LEFT_JOIN or Expression.LEFT_OUTER_JOIN.

Returns:

true if this Join expression is a Expression.LEFT_JOIN or Expression.LEFT_OUTER_JOIN; 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