EclipseLink 2.4.2, build 'v20130514-5956486' API Reference

org.eclipse.persistence.jpa.jpql.parser
Class NullComparisonExpression

java.lang.Object
  extended by org.eclipse.persistence.jpa.jpql.parser.AbstractExpression
      extended by org.eclipse.persistence.jpa.jpql.parser.NullComparisonExpression
All Implemented Interfaces:
Expression

public final class NullComparisonExpression
extends AbstractExpression

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

Version:
2.4.2
Author:
Pascal Filion
Since:
2.3

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, ASC, AVG, BETWEEN, BIT_LENGTH, BOTH, CASE, CAST, CHAR_LENGTH, CHARACTER_LENGTH, CLASS, COALESCE, COLUMN, CONCAT, 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, 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, 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_FIRST, NULLS_LAST, OBJECT, OF, ON, OPERATOR, OR, ORDER_BY, OUTER, PLUS, POSITION, POSITIONAL_PARAMETER, QUOTE, REGEXP, SELECT, SET, SIZE, SOME, SQL, SQRT, SUBSTRING, SUM, TABLE, THEN, TRAILING, TREAT, TRIM, TRUE, TYPE, UNION, UNKNOWN, UPDATE, UPPER, VALUE, WHEN, WHERE
 
Constructor Summary
NullComparisonExpression(AbstractExpression parent, AbstractExpression expression)
          Creates a new NullComparisonExpression.
NullComparisonExpression(AbstractExpression parent, java.lang.String identifier, AbstractExpression expression)
          Creates a new NullComparisonExpression.
 
Method Summary
 void accept(ExpressionVisitor visitor)
          Visits this Expression by the given visitor.
 void acceptChildren(ExpressionVisitor visitor)
          Visits the children of this Expression.
protected  void addChildrenTo(java.util.Collection<Expression> children)
          Adds the children of this AbstractExpression to the given collection.
protected  void addOrderedChildrenTo(java.util.List<Expression> children)
          Adds the children of this AbstractExpression to the given list.
 JPQLQueryBNF findQueryBNF(Expression expression)
          Retrieves the JPQLQueryBNF that represents the fragment of this Expression that was used when parsing the given Expression.
 java.lang.String getActualIsIdentifier()
          Returns the actual IS found in the string representation of the JPQL query, which has the actual case that was used.
 java.lang.String getActualNotIdentifier()
          Returns the actual Not found in the string representation of the JPQL query, which has the actual case that was used.
 java.lang.String getActualNullIdentifier()
          Returns the actual NULL found in the string representation of the JPQL query, which has the actual case that was used.
 Expression getExpression()
          Returns the expression being tested for being null.
 java.lang.String getIdentifier()
          Returns the identifier for this expression that may include NOT if it was parsed.
 JPQLQueryBNF getQueryBNF()
          Returns the BNF of this Expression.
 boolean hasExpression()
          Determines whether the expression preceding the identifier was parsed.
 boolean hasNot()
          Determines whether NOT is used in the query.
protected  void parse(WordParser wordParser, boolean tolerant)
          Parses the query by starting at the current position, which is part of the given WordParser.
protected  void toParsedText(java.lang.StringBuilder writer, boolean actual)
          Generates a string representation of this Expression, including its children, if it has any.
 
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, isParsingComplete, isTolerant, isUnknown, isVirtual, orderedChildren, parse, parseUsingExpressionFactory, populatePosition, 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
 

Constructor Detail

NullComparisonExpression

public NullComparisonExpression(AbstractExpression parent,
                                AbstractExpression expression)
Creates a new NullComparisonExpression.

Parameters:
parent - The parent of this expression
expression - The expression before the identifier

NullComparisonExpression

public NullComparisonExpression(AbstractExpression parent,
                                java.lang.String identifier,
                                AbstractExpression expression)
Creates a new NullComparisonExpression.

Parameters:
parent - The parent of this expression
expression - The expression before the identifier
Method Detail

accept

public void accept(ExpressionVisitor visitor)
Visits this Expression by the given visitor.

Parameters:
visitor - The ExpressionVisitor 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() 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.

addChildrenTo

protected void addChildrenTo(java.util.Collection<Expression> children)
Adds the children of this AbstractExpression to the given collection.

Overrides:
addChildrenTo in class AbstractExpression
Parameters:
children - The collection used to store the children

addOrderedChildrenTo

protected void addOrderedChildrenTo(java.util.List<Expression> children)
Adds the children of this AbstractExpression to the given list.

Overrides:
addOrderedChildrenTo in class AbstractExpression
Parameters:
children - The list used to store the string representation of this AbstractExpression

findQueryBNF

public 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

getActualIsIdentifier

public java.lang.String getActualIsIdentifier()
Returns the actual IS found in the string representation of the JPQL query, which has the actual case that was used.

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

getActualNotIdentifier

public java.lang.String getActualNotIdentifier()
Returns the actual Not found in the string representation of the JPQL query, which has the actual case that was used.

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

getActualNullIdentifier

public java.lang.String getActualNullIdentifier()
Returns the actual NULL found in the string representation of the JPQL query, which has the actual case that was used.

Returns:
The NULL identifier that was actually parsed

getExpression

public Expression getExpression()
Returns the expression being tested for being null.

Returns:
Either the parsed expression or the null-expression

getIdentifier

public java.lang.String getIdentifier()
Returns the identifier for this expression that may include NOT if it was parsed.

Returns:
Either IS NULL or IS NOT NULL

getQueryBNF

public JPQLQueryBNF getQueryBNF()
Returns the BNF of this Expression.

Returns:
The JPQLQueryBNF, which represents the grammar of this Expression

hasExpression

public boolean hasExpression()
Determines whether the expression preceding the identifier was parsed.

Returns:
true the expression preceding the identifier was parsed; false otherwise

hasNot

public boolean hasNot()
Determines whether NOT is used in the query.

Returns:
true if NOT is present in the query; false otherwise

parse

protected 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

protected void toParsedText(java.lang.StringBuilder writer,
                            boolean actual)
Generates a string representation of this Expression, including its children, if it has any.

Specified by:
toParsedText in class AbstractExpression
Parameters:
writer - The buffer used to append this Expression's string representation
actual - 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

EclipseLink 2.4.2, build 'v20130514-5956486' API Reference