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

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.JPQLExpression

All Implemented Interfaces:

Expression

public final class JPQLExpression

extends AbstractExpression

A JPQL expression is the parsed tree representation of a Java Persistence query. The parser supports version 1.0 and 2.0 of the JPA specification.

A JPQL statement may be either a SELECT statement, an UPDATE statement, or a DELETE FROM statement.

BNF: QL_statement ::= select_statement | update_statement | delete_statement

Since:

2.3

Version:

2.3

Author:

Pascal Filion

Field Summary

private AbstractExpression	queryStatement The tree representation of the query.
private boolean	tolerant Determines if the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries.
private AbstractExpression	unknownEndingStatement If the expression could not be fully parsed, meaning some unknown text is trailing the query, this will contain it.
private IJPAVersion	version The version of the JPQL to support, which is the version of the Java Persistence specification.

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

	JPQLExpression(java.lang.CharSequence query, IJPAVersion version) Creates a new JPQLExpression, which is the root of the JPQL parsed tree.
	JPQLExpression(java.lang.CharSequence query, IJPAVersion version, boolean tolerant) Creates a new JPQLExpression, which is the root of the JPQL parsed tree.
private	JPQLExpression(IJPAVersion version, boolean tolerant) Creates a new JPQLExpression, which is the root of the JPQL parsed tree.

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.
private SelectStatement	addSelectStatement()
QueryPosition	buildPosition(java.lang.String actualQuery, int position) Creates an object where the Expression is the leaf at the given position.
private AbstractExpression	buildQueryStatement(WordParser wordParser)
private void	checkQuery(java.lang.CharSequence query)
private void	checkVersion(IJPAVersion version)
Expression	getExpression(java.lang.String actualQuery, int position) Returns the deepest Expression for the given position.
IJPAVersion	getJPAVersion() Returns the version of the Java Persistence to support.
JPQLQueryBNF	getQueryBNF() Returns the BNF of this Expression.
Expression	getQueryStatement() Returns the Expression representing the query, which is either a SELECT, a DELETE or an UPDATE clause.
AbstractExpression	getUnknownEndingStatement() Returns the Expression that may contain a portion of the query that could not be parsed, this happens when the query is either incomplete or malformed.
IJPAVersion	getVersion() Returns the version of the JPQL to support, which is the version of the Java Persistence specification.
boolean	hasQueryStatement() Determines whether a query was parsed.
boolean	hasUnknownEndingStatement() Determines whether the query that got parsed had some malformed or unknown information.
(package private) boolean	isTolerant() Determines if the parser is in tolerant mode or is in fast mode.
(package private) void	parse(WordParser wordParser, boolean tolerant) Parses the query by starting at the current position, which is part of the given WordParser.
static Expression	parseConditionalExpression(java.lang.String abstractSchemaName, java.lang.CharSequence conditionalExpression, IJPAVersion version, boolean tolerant) Creates a new Expression by parsing the string, which represents a conditional expression.
(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, getParent, getRoot, getText, handleAggregate, identifierRole, identifiers, identifiers, identifierVersion, isAncestor, isIdentifier, isNull, isParsingComplete, 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

queryStatement

private AbstractExpression queryStatement

The tree representation of the query.

tolerant

private boolean tolerant

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

unknownEndingStatement

private AbstractExpression unknownEndingStatement

If the expression could not be fully parsed, meaning some unknown text is trailing the query, this will contain it.

version

private IJPAVersion version

The version of the JPQL to support, which is the version of the Java Persistence specification.

Constructor Detail

JPQLExpression

public JPQLExpression(java.lang.CharSequence query,
                      IJPAVersion version)

Creates a new JPQLExpression, which is the root of the JPQL parsed tree.

Parameters:

query - The string representation of the JPQL query to parse

version - The version of the JPQL to support, which is the version of the Java Persistence specification

JPQLExpression

public JPQLExpression(java.lang.CharSequence query,
                      IJPAVersion version,
                      boolean tolerant)

Creates a new JPQLExpression, which is the root of the JPQL parsed tree.

Parameters:

query - The string representation of the JPQL query to parse

version - The version of the JPQL to support, which is the version of the Java Persistence specification

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

JPQLExpression

private JPQLExpression(IJPAVersion version,
                       boolean tolerant)

Creates a new JPQLExpression, which is the root of the JPQL parsed tree.

Parameters:

version - The version of the JPQL to support, which is the version of the Java Persistence specification

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

Method Detail

parseConditionalExpression

public static Expression parseConditionalExpression(java.lang.String abstractSchemaName,
                                                    java.lang.CharSequence conditionalExpression,
                                                    IJPAVersion version,
                                                    boolean tolerant)

Creates a new Expression by parsing the string, which represents a conditional expression.

Parameters:

abstractSchemaName - The abstract schema name for which the identification variable "this" represents

conditionalExpression - The string representation of the conditional expression to parse

version - The version of the JPQL to support, which is the version of the Java Persistence specification

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

Returns:

The Expression representing the given conditional expression

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

addSelectStatement

private SelectStatement addSelectStatement()

buildPosition

public QueryPosition buildPosition(java.lang.String actualQuery,
                                   int position)

Creates an object where the Expression is the leaf at the given position.

Parameters:

actualQuery - The actual query is a string representation of the query that may contain extra whitespace

position - The position of the cursor in the actual query, which is used to retrieve the deepest Expression. The position will be adjusted to fit into the beautified version of the query

Returns:

A new QueryPosition

buildQueryStatement

private AbstractExpression buildQueryStatement(WordParser wordParser)

checkQuery

private void checkQuery(java.lang.CharSequence query)

checkVersion

private void checkVersion(IJPAVersion version)

getExpression

public Expression getExpression(java.lang.String actualQuery,
                                int position)

Returns the deepest Expression for the given position.

Parameters:

actualQuery - The actual query is the text version of the query that may contain extra whitespace and different formatting than the trim down version generated by the parsed tree

position - The position in the actual query used to retrieve the Expression

Returns:

The Expression located at the given position in the given query

getJPAVersion

public IJPAVersion getJPAVersion()

Returns the version of the Java Persistence to support.

Overrides:

getJPAVersion in class AbstractExpression

Returns:

The JPA version

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

getQueryStatement

public Expression getQueryStatement()

Returns the Expression representing the query, which is either a SELECT, a DELETE or an UPDATE clause.

Returns:

The expression representing the Java Persistence query

getUnknownEndingStatement

public AbstractExpression getUnknownEndingStatement()

Returns the Expression that may contain a portion of the query that could not be parsed, this happens when the query is either incomplete or malformed.

Returns:

The expression used when the ending of the query is unknown or malformed

getVersion

public IJPAVersion getVersion()

Returns the version of the JPQL to support, which is the version of the Java Persistence specification.

Returns:

The version that was used to parse the JPQL query

hasQueryStatement

public boolean hasQueryStatement()

Determines whether a query was parsed. The query may be incomplete but it started with one of the three clauses (SELECT, DELETE FROM, or UPDATE).

Returns:

true the query was parsed; false otherwise

hasUnknownEndingStatement

public boolean hasUnknownEndingStatement()

Determines whether the query that got parsed had some malformed or unknown information.

Returns:

true if the query could not be parsed correctly because it is either incomplete or malformed

isTolerant

boolean isTolerant()

Determines if the parser is in tolerant mode or is in fast mode. When the tolerant is turned on, it means the parser will attempt to parse incomplete or invalid queries.

Overrides:

isTolerant in class AbstractExpression

Returns:

true if the parsing system should parse invalid or incomplete queries; false when the query is well-formed and valid

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