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

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

Constructors

Constructor and Description
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.

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(ExpressionVisitor visitor) Visits this Expression by the given visitor.
void	acceptChildren(ExpressionVisitor visitor) Visits the children of this Expression.
QueryPosition	buildPosition(java.lang.String actualQuery, int position) Creates an object where the Expression is the leaf at the given position.
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.
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.

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

children, findQueryBNF, getChildren, getParent, getRoot, identifierRole, identifiers, identifierVersion, isAncestor, isIdentifier, isVirtual, orderedChildren, queryBNF, toActualText, toParsedText, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

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

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.

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

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.

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