/******************************************************************************* * Copyright (c) 2006, 2015 Oracle and/or its affiliates. All rights reserved. * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 * which accompanies this distribution. * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html * and the Eclipse Distribution License is available at * http://www.eclipse.org/org/documents/edl-v10.php. * * Contributors: * Oracle - initial API and implementation * ******************************************************************************/ package org.eclipse.persistence.jpa.jpql.tools.resolver; import java.util.HashMap; import java.util.HashSet; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.Set; import org.eclipse.persistence.jpa.jpql.ExpressionTools; import org.eclipse.persistence.jpa.jpql.LiteralType; import org.eclipse.persistence.jpa.jpql.parser.AbstractExpressionVisitor; import org.eclipse.persistence.jpa.jpql.parser.AbstractSchemaName; import org.eclipse.persistence.jpa.jpql.parser.AnonymousExpressionVisitor; import org.eclipse.persistence.jpa.jpql.parser.CollectionExpression; import org.eclipse.persistence.jpa.jpql.parser.CollectionMemberDeclaration; import org.eclipse.persistence.jpa.jpql.parser.CollectionValuedPathExpression; import org.eclipse.persistence.jpa.jpql.parser.DeleteClause; import org.eclipse.persistence.jpa.jpql.parser.DeleteStatement; import org.eclipse.persistence.jpa.jpql.parser.Expression; import org.eclipse.persistence.jpa.jpql.parser.FromClause; import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariable; import org.eclipse.persistence.jpa.jpql.parser.IdentificationVariableDeclaration; import org.eclipse.persistence.jpa.jpql.parser.JPQLExpression; import org.eclipse.persistence.jpa.jpql.parser.Join; import org.eclipse.persistence.jpa.jpql.parser.NullExpression; import org.eclipse.persistence.jpa.jpql.parser.RangeVariableDeclaration; import org.eclipse.persistence.jpa.jpql.parser.ResultVariable; import org.eclipse.persistence.jpa.jpql.parser.SelectClause; import org.eclipse.persistence.jpa.jpql.parser.SelectStatement; import org.eclipse.persistence.jpa.jpql.parser.SimpleFromClause; import org.eclipse.persistence.jpa.jpql.parser.SimpleSelectClause; import org.eclipse.persistence.jpa.jpql.parser.SimpleSelectStatement; import org.eclipse.persistence.jpa.jpql.parser.SubExpression; import org.eclipse.persistence.jpa.jpql.parser.UpdateClause; import org.eclipse.persistence.jpa.jpql.parser.UpdateStatement; import org.eclipse.persistence.jpa.jpql.tools.JPQLQueryContext; import org.eclipse.persistence.jpa.jpql.tools.spi.IMapping; import org.eclipse.persistence.jpa.jpql.tools.spi.IQuery; import org.eclipse.persistence.jpa.jpql.tools.spi.IType; import org.eclipse.persistence.jpa.jpql.tools.spi.ITypeDeclaration; /** * This {@link Resolver} is responsible to visit the current query (which is either the top-level * query or a subquery) and gathers the information from the declaration clause. For a <b>SELECT</b> * or <b>DELETE</b> clause, the information will be retrieved from the <b>FROM</b> clause. For an * <code>UDPATE</code> clause, it will be retrieved from the unique identification range variable * declaration. * * @version 2.5 * @since 2.3 * @author Pascal Filion */ public class DeclarationResolver extends Resolver { /** * The {@link Declaration Declarations} of the current query that was parsed. */ private List<Declaration> declarations; /** * This visitor is responsible to visit the current query's declaration and populate this * resolver with the list of declarations. */ private DeclarationVisitor declarationVisitor; /** * This visitor is responsible to convert the abstract schema name into a path expression. */ private QualifyRangeDeclarationVisitor qualifyRangeDeclarationVisitor; /** * The context used to query information about the query. */ private JPQLQueryContext queryContext; /** * The identification variable names mapped to their resolvers. */ private Map<String, Resolver> resolvers; /** * The variables identifying the select expressions, if any was defined or an empty set if none * were defined. */ private Map<IdentificationVariable, String> resultVariables; /** * This visitor resolves the "root" object represented by the given {@link Expression}. This will * also handle using a subquery in the <code><b>FROM</b></code> clause. This is only supported by * EclipseLink. */ private RootObjectExpressionVisitor rootObjectExpressionVisitor; /** * Creates a new <code>DeclarationResolver</code>. * * @param parent The parent resolver if this is used for a subquery or null if it's used for the * top-level query * @param queryContext The context used to query information about the query */ public DeclarationResolver(DeclarationResolver parent, JPQLQueryContext queryContext) { super(parent); initialize(queryContext); } /** * Adds the given {@link Declaration} at the end of the list. * * @param declaration The {@link Declaration} representing a single variable declaration */ protected final void addDeclaration(Declaration declaration) { declarations.add(declaration); } /** * Registers a range variable declaration that will be used when a JPQL fragment is parsed. * * @param entityName The name of the entity to be accessible with the given variable name * @param variableName The identification variable used to navigate to the entity */ public void addRangeVariableDeclaration(String entityName, String variableName) { // Always make the identification variable be upper case since it's // case insensitive, the get will also use upper case String internalVariableName = variableName.toUpperCase(); // Make sure the identification variable was not declared more than once, // this could cause issues when trying to resolve it if (!resolvers.containsKey(internalVariableName)) { // Resolve the expression and map it with the identification variable Resolver resolver = new EntityResolver(this, entityName); resolver = new IdentificationVariableResolver(resolver, variableName); resolvers.put(internalVariableName, resolver); RangeDeclaration declaration = new RangeDeclaration(); declaration.rootPath = entityName; declaration.identificationVariable = new IdentificationVariable(null, variableName); declarations.add(declaration); } } protected DeclarationVisitor buildDeclarationVisitor() { return new DeclarationVisitor(); } protected RootObjectExpressionVisitor buildRootObjectExpressionVisitor() { return new RootObjectExpressionVisitor(); } /** * {@inheritDoc} */ @Override protected IType buildType() { return getTypeHelper().unknownType(); } /** * {@inheritDoc} */ @Override protected ITypeDeclaration buildTypeDeclaration() { return getTypeHelper().unknownTypeDeclaration(); } /** * {@inheritDoc} */ @Override protected void checkParent(Resolver parent) { // Don't do anything, this is the root } /** * Converts the given {@link Declaration} from being set as a range variable declaration to * a path expression declaration. * <p> * In this query "<code>UPDATE Employee SET firstName = 'MODIFIED' WHERE (SELECT COUNT(m) FROM * managedEmployees m) {@literal >} 0</code>" <em>managedEmployees</em> is an unqualified * collection-valued path expression (<code>employee.managedEmployees</code>). * * @param declaration The {@link Declaration} that was parsed to range over an abstract schema * name but is actually ranging over a path expression * @param outerVariableName The identification variable coming from the parent identification * variable declaration */ public void convertUnqualifiedDeclaration(Declaration declaration, String outerVariableName) { QualifyRangeDeclarationVisitor visitor = qualifyRangeDeclarationVisitor(); try { visitor.oldDeclaration = declaration; visitor.outerVariableName = outerVariableName; declaration.declarationExpression.accept(visitor); } finally { visitor.oldDeclaration = null; visitor.newDeclaration = null; visitor.outerVariableName = null; } } /** * Disposes the internal data. */ public void dispose() { resolvers .clear(); declarations .clear(); resultVariables.clear(); } /** * Retrieves the {@link Declaration} for which the given variable name is used to navigate to the * "root" object. * * @param variableName The name of the identification variable that is used to navigate a "root" object * @return The {@link Declaration} containing the information about the identification variable declaration * @since 2.5 */ public Declaration getDeclaration(String variableName) { for (Declaration declaration : declarations) { if (declaration.getVariableName().equalsIgnoreCase(variableName)) { return declaration; } } return null; } /** * Returns the ordered list of {@link Declaration Declarations}. * * @return The {@link Declaration Declarations} of the current query that was parsed */ public List<Declaration> getDeclarations() { return declarations; } protected DeclarationVisitor getDeclarationVisitor() { if (declarationVisitor == null) { declarationVisitor = buildDeclarationVisitor(); } return declarationVisitor; } /** * {@inheritDoc} */ @Override public DeclarationResolver getParent() { return (DeclarationResolver) super.getParent(); } /** * {@inheritDoc} */ @Override public IQuery getQuery() { return queryContext.getQuery(); } /** * Returns the {@link JPQLQueryContext} that is used by this visitor. * * @return The {@link JPQLQueryContext} holding onto the JPQL query and the cached information */ protected JPQLQueryContext getQueryContext() { return queryContext; } /** * Retrieves the {@link 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. * * @param variableName The identification variable that maps a {@link Resolver} * @return The {@link Resolver} mapped with the given identification variable */ public Resolver getResolver(String variableName) { variableName = variableName.toUpperCase(); Resolver resolver = getResolverImp(variableName); if ((resolver == null) && (getParent() != null)) { resolver = getParent().getResolver(variableName); } if (resolver == null) { resolver = new NullResolver(this); resolvers.put(variableName, resolver); } return resolver; } /** * Retrieves the {@link Resolver} mapped with the given identification variable. The search does * not traverse the parent hierarchy. * * @param variableName The identification variable that maps a {@link Resolver} * @return The {@link Resolver} mapped with the given identification variable */ protected Resolver getResolverImp(String variableName) { return resolvers.get(variableName); } /** * Returns the variables that got defined in the select expression. This only applies to JPQL * queries built for JPA 2.0 or later. * * @return The variables identifying the select expressions, if any was defined or an empty set * if none were defined */ public Set<String> getResultVariables() { return new HashSet<String>(resultVariables.values()); } /** * Returns the map of result variables that got used to define a select expression. This only * applies to JPQL queries built for JPA 2.0. * * @return The variables identifying the select expressions, if any was defined or an empty map * if none were defined */ public Map<IdentificationVariable, String> getResultVariablesMap() { return resultVariables; } protected RootObjectExpressionVisitor getRootObjectExpressionVisitor() { if (rootObjectExpressionVisitor == null) { rootObjectExpressionVisitor = buildRootObjectExpressionVisitor(); } return rootObjectExpressionVisitor; } /** * Determines whether the JPQL expression has <b>JOIN</b> expressions. * * @return <code>true</code> if the query or subquery being traversed contains <b>JOIN</b> * expressions; <code>false</code> otherwise */ public boolean hasJoins() { for (Declaration declaration : declarations) { if (declaration.hasJoins()) { return true; } } return false; } /** * Initializes this <code>DeclarationResolver</code>. * * @param queryContext The context used to query information about the query */ protected void initialize(JPQLQueryContext queryContext) { this.queryContext = queryContext; this.resolvers = new HashMap<String, Resolver>(); this.declarations = new LinkedList<Declaration>(); this.resultVariables = new HashMap<IdentificationVariable, String>(); } /** * Determines whether the given identification variable is defining a <b>JOIN</b> expression or * in a <code>IN</code> expressions for a collection-valued field. If the search didn't find the * identification in this resolver, then it will traverse the parent hierarchy. * * @param variableName The identification variable to check for what it maps * @return <code>true</code> if the given identification variable maps a collection-valued field * defined in a <code>JOIN</code> or <code>IN</code> expression; <code>false</code> otherwise */ public boolean isCollectionIdentificationVariable(String variableName) { boolean result = isCollectionIdentificationVariableImp(variableName); if (!result && (getParent() != null)) { result = getParent().isCollectionIdentificationVariableImp(variableName); } return result; } /** * Determines whether the given identification variable is defining a <b>JOIN</b> expression or * in a <code>IN</code> expressions for a collection-valued field. The search does not traverse * the parent hierarchy. * * @param variableName The identification variable to check for what it maps * @return <code>true</code> if the given identification variable maps a collection-valued field * defined in a <code>JOIN</code> or <code>IN</code> expression; <code>false</code> otherwise */ protected boolean isCollectionIdentificationVariableImp(String variableName) { for (Declaration declaration : declarations) { switch (declaration.getType()) { case COLLECTION: { if (declaration.getVariableName().equalsIgnoreCase(variableName)) { return true; } return false; } case RANGE: case DERIVED: { AbstractRangeDeclaration rangeDeclaration = (AbstractRangeDeclaration) declaration; // Check the JOIN expressions for (Join join : rangeDeclaration.getJoins()) { String joinVariableName = queryContext.literal( join.getIdentificationVariable(), LiteralType.IDENTIFICATION_VARIABLE ); if (joinVariableName.equalsIgnoreCase(variableName)) { // Make sure the JOIN expression maps a collection mapping Resolver resolver = getResolver(variableName); IMapping mapping = (resolver != null) ? resolver.getMapping() : null; return (mapping != null) && mapping.isCollection(); } } } default: continue; } } return false; } /** * Determines whether the given variable name is an identification variable name mapping an * entity. The search traverses the parent resolver if it is not found in this resolver, which * represents the current JPQL query. * * @param 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 * @return <code>true</code> if the variable name is mapping an abstract schema name; <code>false</code> * if it's defined in a collection member declaration */ public boolean isRangeIdentificationVariable(String variableName) { boolean result = isRangeIdentificationVariableImp(variableName); if (!result && (getParent() != null)) { result = getParent().isRangeIdentificationVariableImp(variableName); } return result; } /** * Determines whether the given variable name is an identification variable name mapping an * entity. The search only searches in this resolver, which represents the current JPQL query. * * @param 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 * @return <code>true</code> if the variable name is mapping an abstract schema name; <code>false</code> * if it's defined in a collection member declaration */ protected boolean isRangeIdentificationVariableImp(String variableName) { for (Declaration declaration : declarations) { if (declaration.getType().isRange() && declaration.getVariableName().equalsIgnoreCase(variableName)) { return true; } } return false; } /** * Determines if the given variable is a result variable. * * @param variable The variable to check if it's a result variable * @return <code>true</code> if the given variable is defined as a result variable; <code>false</code> * otherwise */ public boolean isResultVariable(String variable) { return resultVariables.containsValue(variable.toUpperCase()); } /** * Visits the current query (which is either the top-level query or a subquery) and gathers the * information from the declaration clause. * * @param expression The {@link Expression} to visit in order to retrieve the information * contained in the given query's declaration */ public void populate(Expression expression) { DeclarationVisitor visitor = getDeclarationVisitor(); try { expression.accept(visitor); } finally { visitor.currentDeclaration = null; } } protected QualifyRangeDeclarationVisitor qualifyRangeDeclarationVisitor() { if (qualifyRangeDeclarationVisitor == null) { qualifyRangeDeclarationVisitor = new QualifyRangeDeclarationVisitor(); } return qualifyRangeDeclarationVisitor; } /** * Resolves the "root" object represented by the given {@link Expression}. This will also handle * using a subquery in the <code><b>FROM</b></code> clause. This is only supported by EclipseLink. * * @param expression The {@link Expression} to visit, which represents the "root" object of a * declaration * @return The {@link Resolver} for the given {@link Expression} */ protected Resolver resolveRootObject(Expression expression) { RootObjectExpressionVisitor visitor = getRootObjectExpressionVisitor(); try { expression.accept(visitor); return visitor.resolver; } finally { visitor.resolver = null; } } protected String visitDeclaration(Expression expression, Expression identificationVariable) { // Visit the identification variable expression and retrieve the identification variable name String variableName = queryContext.literal( identificationVariable, LiteralType.IDENTIFICATION_VARIABLE ); // If it's not empty, then we can create a Resolver if (variableName != ExpressionTools.EMPTY_STRING) { // Always make the identification variable be upper case since it's // case insensitive, the get will also use upper case String internalVariableName = variableName.toUpperCase(); // Make sure the identification variable was not declared more than once, // this could cause issues when trying to resolve it if (!resolvers.containsKey(internalVariableName)) { // Resolve the expression and map it with the identification variable Resolver resolver = resolveRootObject(expression); resolver = new IdentificationVariableResolver(resolver, variableName); resolvers.put(internalVariableName, resolver); } return variableName; } return ExpressionTools.EMPTY_STRING; } protected class DeclarationVisitor extends AbstractExpressionVisitor { /** * This flag is used to determine what to do in {@link #visit(SimpleSelectStatement)}. */ protected boolean buildingDeclaration; /** * Flag used to determine if the {@link IdentificationVariable} to visit is a result variable. */ protected boolean collectResultVariable; /** * The {@link Declaration} being populated. */ protected Declaration currentDeclaration; /** * {@inheritDoc} */ @Override public void visit(AbstractSchemaName expression) { currentDeclaration = new RangeDeclaration(); currentDeclaration.rootPath = expression.getText(); declarations.add(currentDeclaration); } /** * {@inheritDoc} */ @Override public void visit(CollectionExpression expression) { expression.acceptChildren(this); } /** * {@inheritDoc} */ @Override public void visit(CollectionMemberDeclaration expression) { CollectionDeclaration declaration = new CollectionDeclaration(); declaration.declarationExpression = expression; declaration.baseExpression = expression.getCollectionValuedPathExpression(); declaration.rootPath = declaration.baseExpression.toActualText(); declarations.add(declaration); // Retrieve the IdentificationVariable Expression identificationVariable = expression.getIdentificationVariable(); String variableName = visitDeclaration(expression, identificationVariable); if (variableName != ExpressionTools.EMPTY_STRING) { declaration.identificationVariable = (IdentificationVariable) identificationVariable; } } /** * {@inheritDoc} */ @Override public void visit(CollectionValuedPathExpression expression) { currentDeclaration = new DerivedDeclaration(); currentDeclaration.rootPath = expression.toActualText(); declarations.add(currentDeclaration); } /** * {@inheritDoc} */ @Override public void visit(DeleteClause expression) { try { buildingDeclaration = true; expression.getRangeVariableDeclaration().accept(this); buildingDeclaration = false; currentDeclaration.declarationExpression = expression; } finally { currentDeclaration = null; } } /** * {@inheritDoc} */ @Override public void visit(DeleteStatement expression) { expression.getDeleteClause().accept(this); } /** * {@inheritDoc} */ @Override public void visit(FromClause expression) { expression.getDeclaration().accept(this); } /** * {@inheritDoc} */ @Override public void visit(IdentificationVariable expression) { if (collectResultVariable) { resultVariables.put(expression, expression.getText().toUpperCase()); } } /** * {@inheritDoc} */ @Override public void visit(IdentificationVariableDeclaration expression) { try { expression.getRangeVariableDeclaration().accept(this); expression.getJoins().accept(this); currentDeclaration.declarationExpression = expression; } finally { currentDeclaration = null; } } /** * {@inheritDoc} */ @Override public void visit(Join expression) { AbstractRangeDeclaration rangeDeclaration = (AbstractRangeDeclaration) currentDeclaration; Expression identificationVariable = expression.getIdentificationVariable(); visitDeclaration(expression, identificationVariable); rangeDeclaration.addJoin(expression); } /** * {@inheritDoc} */ @Override public void visit(JPQLExpression expression) { expression.getQueryStatement().accept(this); } /** * {@inheritDoc} */ @Override public void visit(NullExpression expression) { if (buildingDeclaration) { currentDeclaration = new UnknownDeclaration(); currentDeclaration.baseExpression = expression; currentDeclaration.rootPath = ExpressionTools.EMPTY_STRING; declarations.add(currentDeclaration); } } /** * {@inheritDoc} */ @Override public void visit(RangeVariableDeclaration expression) { // Visit the "root" object, which will create the right Declaration Expression rootObject = expression.getRootObject(); buildingDeclaration = true; rootObject.accept(this); buildingDeclaration = false; // Set the base expression currentDeclaration.baseExpression = expression; // Set the identification variable Expression identificationVariable = expression.getIdentificationVariable(); String variableName = visitDeclaration(rootObject, identificationVariable); if (variableName != ExpressionTools.EMPTY_STRING) { currentDeclaration.identificationVariable = (IdentificationVariable) identificationVariable; } } /** * {@inheritDoc} */ @Override public void visit(ResultVariable expression) { collectResultVariable = true; expression.getResultVariable().accept(this); collectResultVariable = false; } /** * {@inheritDoc} */ @Override public void visit(SelectClause expression) { expression.getSelectExpression().accept(this); } /** * {@inheritDoc} */ @Override public void visit(SelectStatement expression) { expression.getFromClause().accept(this); expression.getSelectClause().accept(this); } /** * {@inheritDoc} */ @Override public void visit(SimpleFromClause expression) { expression.getDeclaration().accept(this); } /** * {@inheritDoc} */ @Override public void visit(SimpleSelectClause expression) { expression.getSelectExpression().accept(this); } /** * {@inheritDoc} */ @Override public void visit(SimpleSelectStatement expression) { expression.getFromClause().accept(this); } /** * {@inheritDoc} */ @Override public void visit(UpdateClause expression) { try { buildingDeclaration = true; expression.getRangeVariableDeclaration().accept(this); buildingDeclaration = false; currentDeclaration.declarationExpression = expression; } finally { currentDeclaration = null; } } /** * {@inheritDoc} */ @Override public void visit(UpdateStatement expression) { expression.getUpdateClause().accept(this); } } protected static class QualifyRangeDeclarationVisitor extends AbstractExpressionVisitor { /** * The new {@link Declaration}. */ protected Declaration newDeclaration; /** * The {@link Declaration} being modified. */ protected Declaration oldDeclaration; /** * The identification variable coming from the parent identification variable declaration. */ protected String outerVariableName; /** * {@inheritDoc} */ @Override public void visit(CollectionValuedPathExpression expression) { newDeclaration.rootPath = expression.toActualText(); newDeclaration.baseExpression = expression; } /** * {@inheritDoc} */ @Override public void visit(IdentificationVariableDeclaration expression) { expression.getRangeVariableDeclaration().accept(this); } /** * {@inheritDoc} */ @Override public void visit(RangeVariableDeclaration expression) { newDeclaration = new DerivedDeclaration(); expression.setVirtualIdentificationVariable(outerVariableName, newDeclaration.rootPath); expression.getRootObject().accept(this); } } /** * This visitor takes care to support a subquery defined as a "root" object. */ protected class RootObjectExpressionVisitor extends AnonymousExpressionVisitor { /** * The {@link Resolver} of the "root" object. */ protected Resolver resolver; /** * {@inheritDoc} */ @Override protected void visit(Expression expression) { resolver = queryContext.getResolver(expression); } /** * {@inheritDoc} */ @Override public void visit(SimpleSelectStatement expression) { resolver = new FromSubqueryResolver( DeclarationResolver.this, DeclarationResolver.this.queryContext, expression ); } /** * {@inheritDoc} */ @Override public void visit(SubExpression expression) { expression.getExpression().accept(this); } } }