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

Class JPQLQueryContext

java.lang.Object
org.eclipse.persistence.jpa.jpql.tools.JPQLQueryContext
Direct Known Subclasses:
DefaultJPQLQueryContext, EclipseLinkJPQLQueryContext
public abstract class JPQLQueryContext extends 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.

Since:
2.3
Version:
2.5

  • Field Details

    • 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 Details

    • 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 Details

    • 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 abstract ParameterTypeVisitor buildParameterTypeVisitor()

    • buildQueryExpressionVisitor

      protected JPQLQueryContext.QueryExpressionVisitor buildQueryExpressionVisitor()

    • 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 Collection<InputParameter> findInputParameters(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

    • getDeclaration

      public Declaration getDeclaration(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

    • getDeclarationResolverImp

      protected DeclarationResolver getDeclarationResolverImp()
      Returns the DeclarationResolver of the current query's declaration.
      Returns:
      The DeclarationResolver for the current query being visited

    • getDeclarations

      public List<Declaration> getDeclarations()
      Returns the ordered list of Declarations.
      Returns:
      The Declarations of the current query that was parsed

    • getEnumType

      public IType getEnumType(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()

    • 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 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.

    • getProviderVersion

      public 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

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

    • isCollectionIdentificationVariable

      public boolean isCollectionIdentificationVariable(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(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(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 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:

    • 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

      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:

    • 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 String toString()
      Overrides:
      toString in class Object