Package org.eclipse.persistence.jpa.jpql.tools

Class 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:
    2.5
    Author:
    Pascal Filion
    Since:
    2.3

    • 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

      • buildLiteralVisitor

        protected abstract LiteralVisitor buildLiteralVisitor()

      • buildResolverBuilder

        protected abstract ResolverBuilder buildResolverBuilder()

      • convertUnqualifiedDeclaration

        public void convertUnqualifiedDeclaration​(Declaration declaration)
        Converts the given 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 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

      • 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

      • getDeclaration

        public Declaration getDeclaration​(java.lang.String variableName)
        Retrieves the Declaration for which the given variable name is used to navigate to the "root" object. This does not go up the hierarchy when looking for the Declaration.
        Parameters:
        variableName - The name of the identification variable that is used to navigate a "root" object
        Returns:
        The Declaration containing the information about the identification variable declaration
        Since:
        2.5

      • 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

      • getDeclarations

        public java.util.List<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

      • 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

      • 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

      • 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.

      • getProviderVersion

        public java.lang.String getProviderVersion()
        Returns the version of the persistence provider.
        Returns:
        The version of the persistence provider, if one is extending the default JPQL grammar defined in the Java Persistence specification, otherwise returns an empty string
        Since:
        2.5

      • getQuery

        public IQuery getQuery()
        Returns the external form of the JPQL query.
        Returns:
        The external form of the JPQL query

      • 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

      • 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​(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

      • 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()
        Initializes the parsed tree representation of the JPQL query if it has not been set before setting the IQuery.

      • 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
        Since:
        2.5

      • isTolerant

        public 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.
        Returns:
        true if the parsing system should parse invalid or incomplete queries; false when the query is well-formed and valid
        Since:
        2.5

      • 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)

      • setTolerant

        public void setTolerant​(boolean tolerant)
        Sets whether 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.

        Note: This needs to be set before setQuery(IQuery) or setJPQLExpression(JPQLExpression) is invoked.

        Parameters:
        tolerant - Determines if the parsing system should be tolerant, meaning if it should try to parse invalid or incomplete queries
        Since:
        2.5

      • 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