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

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.JoinFetch

All Implemented Interfaces:

Expression

public final class JoinFetch

extends AbstractExpression

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

BNF: fetch_join ::= join_spec FETCH join_association_path_expression

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

private boolean	hasSpaceAfterFetch Determines whether a whitespace was parsed after FETCH.
private AbstractExpression	joinAssociationPath The expression of this fetch join.

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

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

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.
java.lang.String	getIdentifier() Returns the identifier this expression represents.
Expression	getJoinAssociationPath() Returns the Expression that represents the join association path expression if it was parsed.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasJoinAssociationPath() Determines whether the join association path expression was parsed.
boolean	hasSpaceAfterFetch() Determines whether a whitespace was found after FETCH.
boolean	isLeftJoinFetch() Determines whether this JoinFetch is a left join fetch, i.e.
(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, isParsingComplete, 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

hasSpaceAfterFetch

private boolean hasSpaceAfterFetch

Determines whether a whitespace was parsed after FETCH.

joinAssociationPath

private AbstractExpression joinAssociationPath

The expression of this fetch join.

Constructor Detail

JoinFetch

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

Creates a new JoinFetch.

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

getIdentifier

public java.lang.String getIdentifier()

Returns the identifier this expression represents.

Returns:

Either INNER JOIN FETCH, JOIN FETCH, LEFT JOIN_FETCH or LEFT OUTER JOIN_FETCH. 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 if it was parsed.

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

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

hasSpaceAfterFetch

public boolean hasSpaceAfterFetch()

Determines whether a whitespace was found after FETCH.

Returns:

true if there was a whitespace after FETCH; false otherwise

isLeftJoinFetch

public boolean isLeftJoinFetch()

Determines whether this JoinFetch is a left join fetch, i.e. Expression.LEFT_JOIN_FETCH or Expression.LEFT_OUTER_JOIN_FETCH.

Returns:

true if this JoinFetch expression is a Expression.LEFT_JOIN_FETCH or Expression.LEFT_OUTER_JOIN_FETCH; false otherwise

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