org.eclipse.persistence.jpa.jpql.parser

Class CastExpression

java.lang.Object

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

org.eclipse.persistence.jpa.jpql.parser.AbstractEncapsulatedExpression

org.eclipse.persistence.jpa.jpql.parser.AbstractSingleEncapsulatedExpression

org.eclipse.persistence.jpa.jpql.parser.CastExpression

All Implemented Interfaces:

Expression

public final class CastExpression
extends AbstractSingleEncapsulatedExpression

The CAST function cast value to a different type. The database type is the second parameter, and can be any valid database type including size and scale.

BNF: expression ::= CAST(scalar_expression [AS] database_type)

Version:

2.5

See Also:

DatabaseType

Author:

James Sutherland

Since:

2.4

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
CastExpression(AbstractExpression parent) Creates a new CastExpression.

Method Summary

Modifier and Type	Method and Description
void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
protected void	addOrderedEncapsulatedExpressionTo(java.util.List<Expression> children) Adds the Expressions representing the encapsulated Expression.
Expression	getDatabaseType() Returns the database type to cast to.
java.lang.String	getEncapsulatedExpressionQueryBNFId() Returns the BNF used to parse the encapsulated expression.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
boolean	hasAs() Determines whether the identifier AS was part of the query.
boolean	hasDatabaseType() Determines whether the database type was parsed or not.
boolean	hasEncapsulatedExpression() Determines whether something was parsed after the left parenthesis.
boolean	hasScalarExpression() Determines whether something was parsed after the left parenthesis and before the AS identifier.
boolean	hasSpaceAfterAs() Determines whether a whitespace parsed after AS.
boolean	hasSpaceAfterExpression() Determines whether a whitespace was parsed after the expression.
protected 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.
protected void	parseEncapsulatedExpression(WordParser wordParser, int whitespaceCount, boolean tolerant) Parses the encapsulated expression by starting at the current position, which is part of the given WordParser.
protected void	removeEncapsulatedExpression() Removes the encapsulated Expression that was parsed, it should not be part of this one.
protected boolean	shouldParseWithFactoryFirst() Determines whether the parsing of the query should be performed using the factories first or it should automatically fallback to the fallback factory.
protected void	toParsedTextEncapsulatedExpression(java.lang.StringBuilder writer, boolean actual) Generates a string representation of the encapsulated Expression.

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

acceptChildren, addChildrenTo, findQueryBNF, getExpression, hasExpression, setExpression

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

addOrderedChildrenTo, areLogicalIdentifiersSupported, getActualIdentifier, getIdentifier, hasLeftParenthesis, hasRightParenthesis, hasSpaceAfterIdentifier, parse, shouldParseRightParenthesis, toParsedText

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

acceptUnknownVisitor, acceptUnknownVisitor, buildExpressionFromFallingBack, buildNullExpression, buildStringExpression, buildStringExpression, buildUnknownExpression, calculatePosition, children, findFallBackExpressionFactory, getExpressionFactory, getExpressionRegistry, getGrammar, getIdentifierVersion, getJPAVersion, getLength, getOffset, getParent, getQueryBNF, getRoot, getText, handleAggregate, handleCollection, isAncestor, isIdentifier, isNull, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, rebuildActualText, rebuildParsedText, setParent, setText, shouldSkipLiteral, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

CastExpression

public CastExpression(AbstractExpression parent)

Creates a new CastExpression.

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 ExpressionVisitor to visit this object

addOrderedEncapsulatedExpressionTo

protected void addOrderedEncapsulatedExpressionTo(java.util.List<Expression> children)

Adds the Expressions representing the encapsulated Expression.

Overrides:

addOrderedEncapsulatedExpressionTo in class AbstractSingleEncapsulatedExpression

Parameters:

children - The list used to store the string representation of the encapsulated Expression

getEncapsulatedExpressionQueryBNFId

public java.lang.String getEncapsulatedExpressionQueryBNFId()

Returns the BNF used to parse the encapsulated expression.

Specified by:

getEncapsulatedExpressionQueryBNFId in class AbstractSingleEncapsulatedExpression

Returns:

The BNF used to parse the encapsulated expression

getDatabaseType

public Expression getDatabaseType()

Returns the database type to cast to.

Returns:

The Expression representing the database type

getQueryBNF

public JPQLQueryBNF getQueryBNF()

Returns the BNF of this Expression.

Returns:

The JPQLQueryBNF, which represents the grammar of this Expression

hasAs

public boolean hasAs()

Determines whether the identifier AS was part of the query.

Returns:

true if the identifier AS was parsed; false otherwise

hasDatabaseType

public boolean hasDatabaseType()

Determines whether the database type was parsed or not.

Returns:

true if the database type was parsed; false otherwise

hasEncapsulatedExpression

public boolean hasEncapsulatedExpression()

Determines whether something was parsed after the left parenthesis.

Overrides:

hasEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

Returns:

true if something was parsed; false otherwise

hasScalarExpression

public boolean hasScalarExpression()

Determines whether something was parsed after the left parenthesis and before the AS identifier.

Returns:

true the expression to be cast was parsed; false otherwise

Since:

2.5

hasSpaceAfterAs

public boolean hasSpaceAfterAs()

Determines whether a whitespace parsed after AS.

Returns:

true if there was a whitespace parsed after AS; false otherwise

hasSpaceAfterExpression

public boolean hasSpaceAfterExpression()

Determines whether a whitespace was parsed after the expression.

Returns:

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

isParsingComplete

protected 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 AbstractEncapsulatedExpression

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

parseEncapsulatedExpression

protected void parseEncapsulatedExpression(WordParser wordParser,
                                           int whitespaceCount,
                                           boolean tolerant)

Parses the encapsulated expression by starting at the current position, which is part of the given WordParser.

Overrides:

parseEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

Parameters:

wordParser - The text to parse based on the current position of the cursor

whitespaceCount - The number of whitespace characters that were parsed after '('

tolerant - Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries

removeEncapsulatedExpression

protected void removeEncapsulatedExpression()

Removes the encapsulated Expression that was parsed, it should not be part of this one. This happens when the parsed information does not have both '(' and ')'.

Overrides:

removeEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

shouldParseWithFactoryFirst

protected boolean shouldParseWithFactoryFirst()

Determines whether the parsing of the query should be performed using the factories first or it should automatically fallback to the fallback factory.

Overrides:

shouldParseWithFactoryFirst in class AbstractExpression

Returns:

true is returned by default so the factories are used before falling back

toParsedTextEncapsulatedExpression

protected void toParsedTextEncapsulatedExpression(java.lang.StringBuilder writer,
                                                  boolean actual)

Generates a string representation of the encapsulated Expression.

Overrides:

toParsedTextEncapsulatedExpression in class AbstractSingleEncapsulatedExpression

Parameters:

writer - The buffer used to append the encapsulated Expression's string representation

actual - 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