org.eclipse.persistence.jpa.jpql
Class JPQLQueryContext

java.lang.Object
  org.eclipse.persistence.jpa.jpql.JPQLQueryContext

Direct Known Subclasses:

DefaultJPQLQueryContext, EclipseLinkJPQLQueryContext

public abstract class JPQLQueryContext
extends java.lang.Object

This context is used to store information related to the JPQL query.

 IQuery externalQuery = ...;

 JPQLQueryContext context = new JPQLQueryContext(DefaultJPQLGrammar.instance());
 context.setQuery(query);

If the JPQL query is already parsed, then the context can use it and it needs to be set before setting the IQuery:

 JPQLExpression jpqlExpression = ...;

 JPQLQueryContext context = new JPQLQueryContext(DefaultJPQLGrammar.instance());
 context.setJPQLExpression(jpqlExpression);
 context.setQuery(query);

Provisional API: This interface is part of an interim API that is still under development and expected to change significantly before reaching stability. It is available at this early stage to solicit feedback from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken (repeatedly) as the API evolves.

Version:

2.4

Author:

Pascal Filion

Since:

2.3

Nested Class Summary

protected class	JPQLQueryContext.InputParameterVisitor This visitor is responsible to find the InputParameters with a certain parameter name.
protected static class	JPQLQueryContext.QueryExpressionVisitor This visitor is responsible to retrieve the Expression that is the beginning of a query.

Field Summary

protected JPQLQueryContext	currentContext The current JPQLQueryContext is the context used for the current query or subquery.
protected JPQLQueryContext	parent When this context is a sub-context used for a subquery, then this is the context for the parent query.

Constructor Summary

	JPQLQueryContext(JPQLGrammar jpqlGrammar) Creates a new JPQLQueryContext.
protected	JPQLQueryContext(JPQLQueryContext parent, Expression currentQuery) Creates a new sub-JPQLQueryContext.

Method Summary

protected DeclarationResolver	buildDeclarationResolver()
protected DeclarationResolver	buildDeclarationResolver(DeclarationResolver parent)
protected JPQLQueryContext.InputParameterVisitor	buildInputParameter()
protected abstract JPQLQueryContext	buildJPQLQueryContext(JPQLQueryContext currentContext, Expression currentQuery)
protected abstract LiteralVisitor	buildLiteralVisitor()
protected ParameterTypeVisitor	buildParameterTypeVisitor()
protected JPQLQueryContext.QueryExpressionVisitor	buildQueryExpressionVisitor()
protected abstract ResolverBuilder	buildResolverBuilder()
void	convertUnqualifiedDeclaration(DeclarationResolver.Declaration declaration) Converts the given DeclarationResolver.Declaration from being set as a range variable declaration to a path expression declaration.
void	dispose() Disposes the internal data.
void	disposeSubqueryContext() Disposes this context, which is the current context being used by a subquery.
java.util.Collection<InputParameter>	findInputParameters(java.lang.String parameterName) Retrieves all the InputParameters with the given parameter name.
Expression	getActualCurrentQuery() Returns the current Expression being manipulated, which is either the top-level query or a subquery.
DeclarationResolver	getActualDeclarationResolver() Returns the DeclarationResolver of this context and not from the current query's declaration.
JPQLQueryContext	getCurrentContext() Returns the current JPQLQueryContext, i.e. the context of the query being manipulated, which can either be the top-level query or a subquery.
Expression	getCurrentQuery() Returns the current Expression being manipulated, which is either the top-level query or a subquery.
DeclarationResolver	getDeclarationResolver() Returns the DeclarationResolver of the current query's declaration.
DeclarationResolver	getDeclarationResolver(Expression expression) Returns the DeclarationResolver of the current query's declaration.
protected DeclarationResolver	getDeclarationResolverImp() Returns the DeclarationResolver of the current query's declaration.
java.util.List<DeclarationResolver.Declaration>	getDeclarations() Returns the ordered list of Declarations.
IType	getEnumType(java.lang.String enumTypeName) Returns the IType representing the possible given enum type.
ExpressionRegistry	getExpressionRegistry() Returns the registry containing the JPQLQueryBNFs and the ExpressionFactories that are used to properly parse a JPQL query.
JPQLGrammar	getGrammar() Returns the JPQL grammar that will be used to define how to parse a JPQL query.
protected JPQLQueryContext.InputParameterVisitor	getInputParameterVisitor()
java.util.Collection<Join>	getJoins(java.lang.String variableName) Returns the parsed representation of a JOIN and JOIN FETCH that were defined in the same declaration than the given range identification variable name.
JPAVersion	getJPAVersion() Returns the version of the Java Persistence to support, which dictates which version of the JPQL grammar to support.
JPQLExpression	getJPQLExpression() Returns the parsed tree representation of the JPQL query.
java.lang.String	getJPQLQuery() Returns the string representation of the JPQL query.
protected LiteralVisitor	getLiteralVisitor()
IMapping	getMapping(Expression expression) Returns the IMapping for the field represented by the given Expression.
IType	getParameterType(InputParameter inputParameter) Retrieves, if it can be determined, the type of the given InputParameter.
protected ParameterTypeVisitor	getParameterTypeVisitor()
JPQLQueryContext	getParent() Returns the parent context if the current context is not the root context.
IManagedTypeProvider	getProvider() Retrieves the provider of managed types.
IQuery	getQuery() Returns the external form of the JPQL query.
Expression	getQueryExpression(Expression expression) Retrieves the Expression representing the query statement (either the top-level query JPQLExpression or the subquery SimpleSelectStatement) owning the given Expression.
protected JPQLQueryContext.QueryExpressionVisitor	getQueryExpressionVisitor()
Resolver	getResolver(Expression expression) Creates or retrieved the cached Resolver for the given Expression.
Resolver	getResolver(java.lang.String variableName) Retrieves the Resolver mapped with the given identification variable.
protected ResolverBuilder	getResolverBuilder()
java.util.Set<java.lang.String>	getResultVariables() Returns the variables that got defined in the select expression.
IType	getType(java.lang.Class<?> type) Retrieves the external type for the given Java type.
IType	getType(Expression expression) Returns the IType of the given Expression.
IType	getType(java.lang.String typeName) Retrieves the external class with the given fully qualified class name.
ITypeDeclaration	getTypeDeclaration(Expression expression) Returns the ITypeDeclaration of the field handled by this Resolver.
TypeHelper	getTypeHelper() Returns a helper that gives access to the most common types.
ITypeRepository	getTypeRepository() Returns the type repository for the application.
boolean	hasJoins() Determines whether the JPQL expression has JOIN expressions.
protected void	initialize(JPQLGrammar jpqlGrammar) Initializes this JPQLQueryContext.
protected void	initializeRoot()
boolean	isCollectionIdentificationVariable(java.lang.String variableName) Determines whether the given identification variable is defining a join or a collection member declaration expressions.
boolean	isRangeIdentificationVariable(java.lang.String variableName) Determines whether the given variable name is an identification variable name used to define an abstract schema name.
boolean	isResultVariable(java.lang.String variable) Determines if the given variable is a result variable.
boolean	isSubquery() Determines whether this JPQLQueryContext currently holds the information of a subquery or for the top-level query.
java.lang.String	literal(Expression expression, LiteralType type) Retrieves the "literal" from the given Expression.
void	newSubqueryContext(Expression currentQuery) Changes the state of this context to use the given subquery.
void	setJPQLExpression(JPQLExpression jpqlExpression) Sets the parsed tree representation of the JPQL query.
void	setQuery(IQuery query) Sets the external form of the JPQL query, which will be parsed and information will be extracted for later access.
protected void	store(JPQLQueryContext parent, Expression currentQuery) Stores the information contained in the given parent into this one.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

currentContext

protected JPQLQueryContext currentContext

The current JPQLQueryContext is the context used for the current query or subquery. If the current context is not the global context, then its parent is non null.

parent

protected JPQLQueryContext parent

When this context is a sub-context used for a subquery, then this is the context for the parent query.

Constructor Detail

JPQLQueryContext

public JPQLQueryContext(JPQLGrammar jpqlGrammar)

Creates a new JPQLQueryContext.

Parameters:

jpqlGrammar - The JPQLGrammar defines how to parse a JPQL query

JPQLQueryContext

protected JPQLQueryContext(JPQLQueryContext parent,
                           Expression currentQuery)

Creates a new sub-JPQLQueryContext.

Parameters:

parent - The parent context

currentQuery - The parsed tree representation of the subquery

Method Detail

buildDeclarationResolver

protected DeclarationResolver buildDeclarationResolver()

buildDeclarationResolver

protected DeclarationResolver buildDeclarationResolver(DeclarationResolver parent)

buildInputParameter

protected JPQLQueryContext.InputParameterVisitor buildInputParameter()

buildJPQLQueryContext

protected abstract JPQLQueryContext buildJPQLQueryContext(JPQLQueryContext currentContext,
                                                          Expression currentQuery)

buildLiteralVisitor

protected abstract LiteralVisitor buildLiteralVisitor()

buildParameterTypeVisitor

protected ParameterTypeVisitor buildParameterTypeVisitor()

buildQueryExpressionVisitor

protected JPQLQueryContext.QueryExpressionVisitor buildQueryExpressionVisitor()

buildResolverBuilder

protected abstract ResolverBuilder buildResolverBuilder()

convertUnqualifiedDeclaration

public void convertUnqualifiedDeclaration(DeclarationResolver.Declaration declaration)

Converts the given DeclarationResolver.Declaration from being set as a range variable declaration to a path expression declaration.

In this query "UPDATE Employee SET firstName = 'MODIFIED' WHERE (SELECT COUNT(m) FROM managedEmployees m) > 0" managedEmployees is an unqualified collection-valued path expression (employee.managedEmployees).

Parameters:

declaration - The DeclarationResolver.Declaration that was parsed to range over an abstract schema name but is actually ranging over a path expression

dispose

public void dispose()

Disposes the internal data.

disposeSubqueryContext

public void disposeSubqueryContext()

Disposes this context, which is the current context being used by a subquery. Once it is disposed, any information retrieved will be for the subquery's parent query.

findInputParameters

public java.util.Collection<InputParameter> findInputParameters(java.lang.String parameterName)

Retrieves all the InputParameters with the given parameter name.

Parameters:

parameterName - The parameter used to find the InputParameters with the same value

Returns:

Either the InputParameters that has the given parameter or an empty collection

getActualCurrentQuery

public Expression getActualCurrentQuery()

Returns the current Expression being manipulated, which is either the top-level query or a subquery.

Returns:

Either the top-level query or a subquery

getActualDeclarationResolver

public DeclarationResolver getActualDeclarationResolver()

Returns the DeclarationResolver of this context and not from the current query's declaration.

Returns:

The DeclarationResolver for this context

getCurrentContext

public JPQLQueryContext getCurrentContext()

Returns the current JPQLQueryContext, i.e. the context of the query being manipulated, which can either be the top-level query or a subquery.

Returns:

The active context

getCurrentQuery

public Expression getCurrentQuery()

Returns the current Expression being manipulated, which is either the top-level query or a subquery.

Returns:

Either the top-level query or a subquery

getDeclarationResolver

public DeclarationResolver getDeclarationResolver()

Returns the DeclarationResolver of the current query's declaration. For a SELECT query, it contains the information defined in the FROM clause. For DELETE and UPDATE queries, it contains a single range declaration variable. If the current query is a subquery, then it contains the information defined in the FROM clause.

Returns:

The DeclarationResolver for the current query being visited

getDeclarationResolver

public DeclarationResolver getDeclarationResolver(Expression expression)

Returns the DeclarationResolver of the current query's declaration. For a SELECT query, it contains the information defined in the FROM clause. For DELETE and UPDATE queries, it contains a single range variable declaration. If the current query is a subquery, then it contains the information defined in the subquery FROM clause.

Parameters:

expression - The Expression that will be used to retrieve its query expression, i.e. either JPQLExpression or SimpleSelectStatement

Returns:

The DeclarationResolver for the current query being visited

getDeclarationResolverImp

protected DeclarationResolver getDeclarationResolverImp()

Returns the DeclarationResolver of the current query's declaration.

Returns:

The DeclarationResolver for the current query being visited

getDeclarations

public java.util.List<DeclarationResolver.Declaration> getDeclarations()

Returns the ordered list of Declarations.

Returns:

The Declarations of the current query that was parsed

getEnumType

public IType getEnumType(java.lang.String enumTypeName)

Returns the IType representing the possible given enum type. If the type name

Parameters:

enumTypeName - The fully qualified enum type with the constant

Returns:

The external form for the given Enum type

getExpressionRegistry

public ExpressionRegistry getExpressionRegistry()

Returns the registry containing the JPQLQueryBNFs and the ExpressionFactories that are used to properly parse a JPQL query.

Returns:

The registry containing the information related to the JPQL grammar

getGrammar

public JPQLGrammar getGrammar()

Returns the JPQL grammar that will be used to define how to parse a JPQL query.

Returns:

The grammar that was used to parse this Expression

getInputParameterVisitor

protected JPQLQueryContext.InputParameterVisitor getInputParameterVisitor()

getJoins

public java.util.Collection<Join> getJoins(java.lang.String variableName)

Returns the parsed representation of a JOIN and JOIN FETCH that were defined in the same declaration than the given range identification variable name.

Parameters:

variableName - The name of the identification variable that should be used to define an abstract schema name

Returns:

The JOIN and JOIN FETCH expressions used in the same declaration or an empty collection if none was defined

getJPAVersion

public JPAVersion getJPAVersion()

Returns the version of the Java Persistence to support, which dictates which version of the JPQL grammar to support.

Returns:

The version of the supported Java Persistence functional specification

getJPQLExpression

public JPQLExpression getJPQLExpression()

Returns the parsed tree representation of the JPQL query.

Returns:

The parsed tree representation of the JPQL query

getJPQLQuery

public java.lang.String getJPQLQuery()

Returns the string representation of the JPQL query.

Returns:

The string representation of the JPQL query

getLiteralVisitor

protected LiteralVisitor getLiteralVisitor()

getMapping

public IMapping getMapping(Expression expression)

Returns the IMapping for the field represented by the given Expression.

Parameters:

expression - The Expression representing a state field path expression or a collection-valued path expression

Returns:

Either the IMapping or null if none exists

getParameterType

public IType getParameterType(InputParameter inputParameter)

Retrieves, if it can be determined, the type of the given InputParameter. The type will be guessed based on its location within expression.

Note: Both named and positional input parameter can be used.

Parameters:

inputParameter - The InputParameter to retrieve its type

Returns:

Either the closest type of the input parameter or null if the type could not be determined

getParameterTypeVisitor

protected ParameterTypeVisitor getParameterTypeVisitor()

getParent

public JPQLQueryContext getParent()

Returns the parent context if the current context is not the root context.

Returns:

The parent context or null if the current context is the root

getProvider

public IManagedTypeProvider getProvider()

Retrieves the provider of managed types.

Returns:

The object that has access to the application's managed types.

getQuery

public IQuery getQuery()

Returns the external form of the JPQL query.

Returns:

The external form of the JPQL query

getQueryExpression

public Expression getQueryExpression(Expression expression)

Retrieves the Expression representing the query statement (either the top-level query JPQLExpression or the subquery SimpleSelectStatement) owning the given Expression.

Parameters:

expression - A child of the "root" Expression to retrieve

Returns:

The query statement that is the "root" parent of the given Expression

getQueryExpressionVisitor

protected JPQLQueryContext.QueryExpressionVisitor getQueryExpressionVisitor()

getResolver

public Resolver getResolver(Expression expression)

Creates or retrieved the cached Resolver for the given Expression. The Resolver can return the IType and ITypeDeclaration of the Expression and either the IManagedType or the IMapping.

Parameters:

expression - The Expression for which its Resolver will be retrieved

Returns:

Resolver for the given Expression

getResolver

public Resolver getResolver(java.lang.String variableName)

Retrieves the Resolver mapped with the given identification variable. If the identification is not defined in the declaration traversed by this resolver, than the search will traverse the parent hierarchy.

Parameters:

variableName - The identification variable that maps a Resolver

Returns:

The Resolver mapped with the given identification variable

getResolverBuilder

protected ResolverBuilder getResolverBuilder()

getResultVariables

public java.util.Set<java.lang.String> getResultVariables()

Returns the variables that got defined in the select expression. This only applies to JPQL queries built for JPA 2.0.

Returns:

The variables identifying the select expressions, if any was defined or an empty set if none were defined

getType

public IType getType(java.lang.Class<?> type)

Retrieves the external type for the given Java type.

Parameters:

type - The Java type to wrap with an external form

Returns:

The external form of the given type

getType

public IType getType(Expression expression)

Returns the IType of the given Expression.

Parameters:

expression - The Expression for which its type will be calculated

Returns:

Either the IType that was resolved by this Resolver or the IType for IType.UNRESOLVABLE_TYPE if it could not be resolved

getType

public IType getType(java.lang.String typeName)

Retrieves the external class with the given fully qualified class name.

Parameters:

typeName - The fully qualified class name of the class to retrieve

Returns:

The external form of the class to retrieve

getTypeDeclaration

public ITypeDeclaration getTypeDeclaration(Expression expression)

Returns the ITypeDeclaration of the field handled by this Resolver.

Parameters:

expression - The Expression for which its type declaration will be calculated

Returns:

Either the ITypeDeclaration that was resolved by this Resolver or the ITypeDeclaration for IType.UNRESOLVABLE_TYPE if it could not be resolved

getTypeHelper

public TypeHelper getTypeHelper()

Returns a helper that gives access to the most common types.

Returns:

A helper containing a collection of methods related to IType

getTypeRepository

public ITypeRepository getTypeRepository()

Returns the type repository for the application.

Returns:

The repository of ITypes

hasJoins

public boolean hasJoins()

Determines whether the JPQL expression has JOIN expressions.

Returns:

true if the query or subquery being traversed contains JOIN expressions; false otherwise

initialize

protected void initialize(JPQLGrammar jpqlGrammar)

Initializes this JPQLQueryContext.

Parameters:

jpqlGrammar - The grammar that defines how to parse a JPQL query

initializeRoot

protected void initializeRoot()

isCollectionIdentificationVariable

public boolean isCollectionIdentificationVariable(java.lang.String variableName)

Determines whether the given identification variable is defining a join or a collection member declaration expressions.

Parameters:

variableName - The identification variable to check for what it maps

Returns:

true if the given identification variable maps a collection-valued field defined in a JOIN or IN expression; false if it's not defined or it's mapping an abstract schema name

isRangeIdentificationVariable

public boolean isRangeIdentificationVariable(java.lang.String variableName)

Determines whether the given variable name is an identification variable name used to define an abstract schema name.

Parameters:

variableName - The name of the variable to verify if it's defined in a range variable declaration in the current query or any parent query

Returns:

true if the variable name is mapping an abstract schema name; false if it's defined in a collection member declaration

isResultVariable

public boolean isResultVariable(java.lang.String variable)

Determines if the given variable is a result variable.

Parameters:

variable - The variable to check if it's a result variable

Returns:

true if the given variable is defined as a result variable; false otherwise

isSubquery

public boolean isSubquery()

Determines whether this JPQLQueryContext currently holds the information of a subquery or for the top-level query.

Returns:

true if the current context is for a subquery; false for the top-level query

literal

public java.lang.String literal(Expression expression,
                                LiteralType type)

Retrieves the "literal" from the given Expression. The literal to retrieve depends on the given type. The literal is basically a string value like an identification variable name, an input parameter, a path expression, an abstract schema name, etc.

Parameters:

expression - The Expression to visit

type - The LiteralType helps to determine what to retrieve from the visited Expression

Returns:

A value from the given Expression or an empty string if the given Expression and the LiteralType do not match

newSubqueryContext

public void newSubqueryContext(Expression currentQuery)

Changes the state of this context to use the given subquery.

Parameters:

currentQuery - The parsed tree representation of the subquery that will become the current query

See Also:

disposeSubqueryContext()

setJPQLExpression

public void setJPQLExpression(JPQLExpression jpqlExpression)

Sets the parsed tree representation of the JPQL query. If the expression was parsed outside of the scope of this context, then this method has to be invoked before setQuery(IQuery) because the JPQL query is automatically parsed by that method.

Parameters:

jpqlExpression - The parsed representation of the JPQL query to manipulate

See Also:

setQuery(IQuery)

setQuery

public void setQuery(IQuery query)

Sets the external form of the JPQL query, which will be parsed and information will be extracted for later access.

Parameters:

query - The external form of the JPQL query

See Also:

setJPQLExpression(JPQLExpression)

store

protected void store(JPQLQueryContext parent,
                     Expression currentQuery)

Stores the information contained in the given parent into this one.

Parameters:

parent - The parent context, which is the context of the parent query

currentQuery - The subquery becoming the current query

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object