Top Description Fields Constructors Methods
org.eclipse.persistence.jpa.jpql.parser

public final Class NullComparisonExpression

extends AbstractExpression
Class Inheritance
Imports
java.util.Collection, .List, org.eclipse.persistence.jpa.jpql.ExpressionTools, .WordParser
A null comparison tests whether or not the single-valued path expression or input parameter is a NULL value.
BNF: null_comparison_expression ::= {single_valued_path_expression | input_parameter} IS [NOT] NULL
Author
Pascal Filion
Since
2.3
Version
2.5

Field Summary

Modifier and TypeField and Description
private AbstractExpression
expression

The expression tested for being null or not.

private String
isIdentifier

The actual IS identifier found in the string representation of the JPQL query.

private String
notIdentifier

The actual IS identifier found in the string representation of the JPQL query.

private String
nullIdentifier

The actual NULL identifier found in the string representation of the JPQL query.

Inherited from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression:
COMMADOTDOUBLE_QUOTELEFT_CURLY_BRACKETLEFT_PARENTHESISNOT_DEFINEDRIGHT_CURLY_BRACKETRIGHT_PARENTHESISSINGLE_QUOTESPACEUNDERSCORE

Constructor Summary

AccessConstructor and Description
public
NullComparisonExpression(AbstractExpression
The parent of this expression
parent, String identifier, AbstractExpression
The expression before the identifier
expression)

Creates a new NullComparisonExpression.

Method Summary

Modifier and TypeMethod and Description
public void
accept(ExpressionVisitor
The ExpressionVisitor to visit this object
visitor)

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.accept.

Visits this Expression by the given visitor.
public void
acceptChildren(ExpressionVisitor
The visitor to visit the children of this object.
visitor)

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.acceptChildren.

Visits the children of this Expression.
protected void
addChildrenTo(Collection<Expression>
The collection used to store the children
children)

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

Adds the children of this AbstractExpression to the given collection.
protected void
addOrderedChildrenTo(List<Expression>
The list used to store the string representation of this AbstractExpression
children)

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

Adds the children of this AbstractExpression to the given list.
public JPQLQueryBNF
findQueryBNF(Expression
The Expression that is a descendant of this one
expression)

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

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.findQueryBNF.

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

Returns:

The IS identifier that was actually parsed, or an empty string if it was not parsed
getActualIsIdentifier()

Returns the actual IS found in the string representation of the JPQL query, which has the actual case that was used.

public String

Returns:

The NOT identifier that was actually parsed, or an empty string if it was not parsed
getActualNotIdentifier()

Returns the actual Not found in the string representation of the JPQL query, which has the actual case that was used.

public String

Returns:

The NULL identifier that was actually parsed
getActualNullIdentifier()

Returns the actual NULL found in the string representation of the JPQL query, which has the actual case that was used.

public Expression

Returns:

Either the parsed expression or the null-expression
getExpression()

Returns the expression being tested for being null.

public String

Returns:

Either IS NULL or IS NOT NULL
getIdentifier()

Returns the identifier for this expression that may include NOT if it was parsed.

public JPQLQueryBNF
getQueryBNF()

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.getQueryBNF.

Returns the BNF of this Expression.
public boolean

Returns:

true the expression preceding the identifier was parsed; false otherwise
hasExpression()

Determines whether the expression preceding the identifier was parsed.

public boolean

Returns:

true if NOT is present in the query; false otherwise
hasNot()

Determines whether NOT is used in the query.

protected void
parse(WordParser
The text to parse based on the current position of the cursor
wordParser, boolean
Determines whether the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries
tolerant)

Implements abstract org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.parse.

Parses the query by starting at the current position, which is part of the given WordParser.
protected void
toParsedText(StringBuilder
The buffer used to append this Expression's string representation
writer, boolean
Determines whether the string representation should represent what was parsed, i.e. include any "virtual" whitespace (such as ending whitespace) and the actual case of the JPQL identifiers
actual)

Implements abstract org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.toParsedText.

Generates a string representation of this Expression, including its children, if it has any.
Inherited from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression:
acceptUnknownVisitoracceptUnknownVisitorbuildExpressionFromFallingBackbuildNullExpressionbuildStringExpressionbuildStringExpressionbuildUnknownExpressioncalculatePositionchildrenfindFallBackExpressionFactorygetExpressionFactorygetExpressionRegistrygetGrammargetIdentifierVersiongetJPAVersiongetLengthgetOffsetgetParentgetQueryBNFgetRootgetTexthandleAggregatehandleCollectionisAncestorisIdentifierisNullisParsingCompleteisTolerantisUnknownisVirtualorderedChildrenparseparseUsingExpressionFactorypopulatePositionrebuildActualTextrebuildParsedTextsetParentsetTextshouldParseWithFactoryFirstshouldSkipLiteraltoActualTexttoParsedTexttoString

Field Detail

expressionback to summary
private AbstractExpression expression

The expression tested for being null or not.

isIdentifierback to summary
private String isIdentifier

The actual IS identifier found in the string representation of the JPQL query.

notIdentifierback to summary
private String notIdentifier

The actual IS identifier found in the string representation of the JPQL query.

nullIdentifierback to summary
private String nullIdentifier

The actual NULL identifier found in the string representation of the JPQL query.

Constructor Detail

NullComparisonExpressionback to summary
public NullComparisonExpression(AbstractExpression parent, String identifier, AbstractExpression expression)

Creates a new NullComparisonExpression.

Parameters
parent:AbstractExpression

The parent of this expression

expression:AbstractExpression

The expression before the identifier

Method Detail

acceptback to summary
public void accept(ExpressionVisitor visitor)

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.accept.

Doc from org.eclipse.persistence.jpa.jpql.parser.Expression.accept.

Visits this Expression by the given visitor.

Parameters
visitor:ExpressionVisitor

The ExpressionVisitor to visit this object

Annotations
@Override
acceptChildrenback to summary
public void acceptChildren(ExpressionVisitor visitor)

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.acceptChildren.

Doc from org.eclipse.persistence.jpa.jpql.parser.Expression.acceptChildren.

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 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:ExpressionVisitor

The visitor to visit the children of this object.

Annotations
@Override
addChildrenToback to summary
protected void addChildrenTo(Collection<Expression> children)

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

Doc from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.addChildrenTo.

Adds the children of this AbstractExpression to the given collection.

Parameters
children:Collection<Expression>

The collection used to store the children

Annotations
@Override
addOrderedChildrenToback to summary
protected void addOrderedChildrenTo(List<Expression> children)

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

Doc from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.addOrderedChildrenTo.

Adds the children of this AbstractExpression to the given list.

Parameters
children:List<Expression>

The list used to store the string representation of this AbstractExpression

Annotations
@Override
findQueryBNFback to summary
public JPQLQueryBNF findQueryBNF(Expression expression)

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

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.findQueryBNF.

Doc from org.eclipse.persistence.jpa.jpql.parser.Expression.findQueryBNF.

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

Parameters
expression:Expression

The Expression that is a descendant of this one

Returns:JPQLQueryBNF

The JPQLQueryBNF that was used to parse the given expression

Annotations
@Override
getActualIsIdentifierback to summary
public String getActualIsIdentifier()

Returns the actual IS found in the string representation of the JPQL query, which has the actual case that was used.

Returns:String

The IS identifier that was actually parsed, or an empty string if it was not parsed

getActualNotIdentifierback to summary
public String getActualNotIdentifier()

Returns the actual Not found in the string representation of the JPQL query, which has the actual case that was used.

Returns:String

The NOT identifier that was actually parsed, or an empty string if it was not parsed

getActualNullIdentifierback to summary
public String getActualNullIdentifier()

Returns the actual NULL found in the string representation of the JPQL query, which has the actual case that was used.

Returns:String

The NULL identifier that was actually parsed

getExpressionback to summary
public Expression getExpression()

Returns the expression being tested for being null.

Returns:Expression

Either the parsed expression or the null-expression

getIdentifierback to summary
public String getIdentifier()

Returns the identifier for this expression that may include NOT if it was parsed.

Returns:String

Either IS NULL or IS NOT NULL

getQueryBNFback to summary
public JPQLQueryBNF getQueryBNF()

Implements org.eclipse.persistence.jpa.jpql.parser.Expression.getQueryBNF.

Doc from org.eclipse.persistence.jpa.jpql.parser.Expression.getQueryBNF.

Returns the BNF of this Expression.

Returns:JPQLQueryBNF

The JPQLQueryBNF, which represents the grammar of this Expression

Annotations
@Override
hasExpressionback to summary
public boolean hasExpression()

Determines whether the expression preceding the identifier was parsed.

Returns:boolean

true the expression preceding the identifier was parsed; false otherwise

hasNotback to summary
public boolean hasNot()

Determines whether NOT is used in the query.

Returns:boolean

true if NOT is present in the query; false otherwise

parseback to summary
protected void parse(WordParser wordParser, boolean tolerant)

Implements abstract org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.parse.

Doc from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.parse.

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

Parameters
wordParser:WordParser

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

tolerant:boolean

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

Annotations
@Override
toParsedTextback to summary
protected void toParsedText(StringBuilder writer, boolean actual)

Implements abstract org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.toParsedText.

Doc from org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.toParsedText.

Generates a string representation of this Expression, including its children, if it has any.

Parameters
writer:StringBuilder

The buffer used to append this Expression's string representation

actual:boolean

Determines whether the string representation should represent what was parsed, i.e. include any "virtual" whitespace (such as ending whitespace) and the actual case of the JPQL identifiers

Annotations
@Override