foundation/org.eclipse.persistence.core/src/main/java/org/eclipse/persistence/internal/jpa/parsing/VariableNode.java - eclipselink - Git at Google

 /*
  * Copyright (c) 1998, 2021 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 v. 2.0 which is available at
  * http://www.eclipse.org/legal/epl-2.0,
  * or the Eclipse Distribution License v. 1.0 which is available at
  * http://www.eclipse.org/org/documents/edl-v10.php.
  *
  * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
  */

 // Contributors:
 //     Oracle - initial API and implementation from Oracle TopLink
 package org.eclipse.persistence.internal.jpa.parsing;

 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;

 // TopLink imports
 import org.eclipse.persistence.exceptions.JPQLException;
 import org.eclipse.persistence.expressions.Expression;
 import org.eclipse.persistence.expressions.ExpressionBuilder;
 import org.eclipse.persistence.internal.expressions.ConstantExpression;
 import org.eclipse.persistence.queries.ObjectLevelReadQuery;
 import org.eclipse.persistence.queries.ReportQuery;

 /**
  * INTERNAL
  * <p><b>Purpose</b>: The node that represents typed variables, local variables, remote variables and TYPE constants.
  *
  *    @author Jon Driscoll and Joel Lucuik
  *    @since TopLink 4.0
  */
 public class VariableNode extends Node implements AliasableNode {

     /** */
     private String variableName;

     /** */
     private String canonicalName;

     /** if this represents a type constant, this value will be populated by validate **/
     private Object classConstant = null;

     /**
      * VariableNode constructor comment.
      */
     public VariableNode() {
         super();
     }

     public VariableNode(String newVariableName) {
         setVariableName(newVariableName);
     }

     public String getVariableName() {
         return variableName;
     }

     public void setVariableName(String newVariableName) {
         variableName = newVariableName;
         canonicalName = IdentificationVariableDeclNode.calculateCanonicalName(newVariableName);
     }

     /** */
     public String getCanonicalVariableName() {
         return canonicalName;
     }

     /**
      * INTERNAL
      * Is this node a VariableNode
      */
     @Override
     public boolean isVariableNode() {
         return true;
     }

     /**
      * INTERNAL
      * Apply this node to the passed query
      */
     @Override
     public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext generationContext) {
         String name = getCanonicalVariableName();
         if (theQuery instanceof ReportQuery) {
             ReportQuery reportQuery = (ReportQuery)theQuery;
             Expression expression = generationContext.expressionFor(name);
             if (expression == null) {
                 expression = generateExpression(generationContext);
             }
             addAttributeWithFetchJoins(reportQuery, expression, generationContext);
         } else {
             addFetchJoins(theQuery, generationContext);
         }
     }

     /**
      * INTERNAL
      * Add the variable as ReportQuery item. The method checks for any JOIN
      * FETCH nodes of the current variable and adds them as part of the
      * ReportQuery item.
      */
     private void addAttributeWithFetchJoins(ReportQuery reportQuery,
                                             Expression expression,
                                             GenerationContext context) {
         String name = getCanonicalVariableName();
         List<Node> fetchJoinNodes = context.getParseTreeContext().getFetchJoins(name);
         if (fetchJoinNodes == null) {
             reportQuery.addAttribute(name, expression);
         } else {
             List<Expression> fetchJoinExprs = new ArrayList<>(fetchJoinNodes.size());
             for (Iterator<Node> i = fetchJoinNodes.iterator(); i.hasNext(); ) {
                 Node node = i.next();
                 fetchJoinExprs.add(node.generateExpression(context));
             }
             reportQuery.addItem(name, expression, fetchJoinExprs);
         }
     }

     /**
      * INTERNAL
      * Check for any JOIN FETCH nodes of the current variable and add them as
      * joined attributes. This method is called in case of a non ReportQuery
      * instance.
      */
     private void addFetchJoins(ObjectLevelReadQuery theQuery,
                                GenerationContext context) {
         String name = getCanonicalVariableName();
         List<Node> fetchJoinNodes = context.getParseTreeContext().getFetchJoins(name);
         if (fetchJoinNodes != null) {
             for (Iterator<Node> i = fetchJoinNodes.iterator(); i.hasNext(); ) {
                 Node node = i.next();
                 theQuery.addJoinedAttribute(node.generateExpression(context));
             }
         }
     }

     /**
      * INTERNAL
      * This node represent an unqualified field access in the case the method
      * is called and the variableName is not defined as identification variable.
      * The method returns a DotNode representing a qualified field access with
      * the base variable as left child node. The right child node is an
      * AttributeNode using the variableName as field name.
      */
     @Override
     public Node qualifyAttributeAccess(ParseTreeContext context) {
         return context.isVariable(variableName) ? this :
             (Node)context.getNodeFactory().newQualifiedAttribute(
                 getLine(), getColumn(), context.getBaseVariable(), variableName);
     }

     /**
      * INTERNAL
      * Validate node and calculate its type.
      */
     @Override
     public void validate(ParseTreeContext context) {
         TypeHelper typeHelper = context.getTypeHelper();
         classConstant = typeHelper.resolveSchema(variableName);
         if (classConstant != null){
             setType(Class.class);
             return;
         }
         String name = getCanonicalVariableName();
         if (context.isRangeVariable(name)) {
             String schema = context.schemaForVariable(name);
             setType(typeHelper.resolveSchema(schema));
         } else {
             Node path = context.pathForVariable(name);
             if (path == null) {
                 throw JPQLException.aliasResolutionException(
                     context.getQueryInfo(), getLine(), getColumn(), name);
             } else {
                 setType(path.getType());
             }
         }
         context.usedVariable(name);
         if (context.isDeclaredInOuterScope(name)) {
             context.registerOuterScopeVariable(name);
         }
     }

     public Expression generateBaseBuilderExpression(GenerationContext context) {
         //create builder, and add it, and answer it
         //BUG 3106877: Need to create builder using the actual class (if using parallel expressions)
         return new ExpressionBuilder(this.resolveClass(context));
     }

     @Override
     public Expression generateExpression(GenerationContext generationContext) {
         Expression myExpression = null;
         String name = getCanonicalVariableName();

         //is there a cached Expression?
         myExpression = generationContext.expressionFor(name);
         if (myExpression != null) {
             return myExpression;
         }

         //Either I have an alias type, or I'm an IN declaration
         if (classConstant != null){
             myExpression = new ConstantExpression(classConstant, generationContext.getBaseExpression());
         } else if (generationContext.getParseTreeContext().isRangeVariable(name)) {
             myExpression = generateBaseBuilderExpression(generationContext);
         } else {
             myExpression = generateExpressionForAlias(generationContext);
         }

         generationContext.addExpression(myExpression, name);
         return myExpression;
     }

     public Expression generateExpressionForAlias(GenerationContext context) {
         // BUG 3105651: Verify if we need to resolve this alias, or just use
         // an empty ExpressionBuilder. See OrderByItemNode.generateExpression()
         // for more details
         if (context.getParseTree().getQueryNode().isSelectNode() && context.shouldCheckSelectNodeBeforeResolving() && (((SelectNode)context.getParseTree().getQueryNode()).isSelected(this.getCanonicalVariableName()))) {
             return new ExpressionBuilder();
         }

         Node nodeForAlias = getNodeForAlias(context);

         //assume that if there is no node available for the given variable, then
         //there must be an alias mismatch. Assume they know their attribute names better
         //than their alias names. - JGL
         if (nodeForAlias == null) {
             throw JPQLException.aliasResolutionException(
                 context.getParseTreeContext().getQueryInfo(),
                 getLine(), getColumn(), getVariableName());
         }

         //create builder, and answer it
         return nodeForAlias.generateExpression(context);
     }

     public Node getNodeForAlias(GenerationContext context) {
         //Node node = context.getParseTreeContext().nodeForIdentifier(getCanonicalVariableName());
         //return node != null ? ((IdentificationVariableDeclNode)node).getPath() : null;
         return context.getParseTreeContext().pathForVariable(getCanonicalVariableName());
     }

     /**
      * isAlias: Answer true if this variable represents an alias in the FROM clause.
      * i.e. "FROM Employee emp" declares "emp" as an alias
      */
     public boolean isAlias(GenerationContext context) {
         return isAlias(context.getParseTreeContext());
     }

     public boolean isAlias(ParseTreeContext context) {
         String classNameForAlias = context.schemaForVariable(getCanonicalVariableName());
         return classNameForAlias != null;
     }

     /**
      * resolveClass: Answer the class which corresponds to my variableName. This is the class for
      * an alias, where the variableName is registered to an alias.
      */
     @Override
     public Class<?> resolveClass(GenerationContext generationContext) {
         Class<?> clazz = null;
         String name = getCanonicalVariableName();
         ParseTreeContext context = generationContext.getParseTreeContext();
         if (context.isRangeVariable(name)) {
             String schema = context.schemaForVariable(name);
             clazz = context.classForSchemaName(schema, generationContext);
         } else {
             DotNode path = (DotNode)context.pathForVariable(name);
             if (path == null) {
                 throw JPQLException.aliasResolutionException(
                     context.getQueryInfo(), getLine(), getColumn(), name);
             } else {
                 clazz = path.resolveClass(generationContext);
             }
         }
         return clazz;
     }

     @Override
     public String toString(int indent) {
         StringBuilder buffer = new StringBuilder();
         toStringIndent(indent, buffer);
         buffer.append(toStringDisplayName()).append("[").append(getVariableName()).append("]");
         return buffer.toString();
     }

     /**
      * INTERNAL
      * Get the string representation of this node.
      */
     @Override
     public String getAsString() {
         return getVariableName();
     }

     public Object getTypeForMapKey(ParseTreeContext context){
         String name = getCanonicalVariableName();
         if (context.isRangeVariable(name)) {
             throw JPQLException.variableCannotHaveMapKey(context.getQueryInfo(), getLine(), getColumn(), name);
         } else {
             DotNode path = (DotNode)context.pathForVariable(name);
             if (path == null) {
                 throw JPQLException.aliasResolutionException(
                     context.getQueryInfo(), getLine(), getColumn(), name);
             } else {
                 return path.getTypeForMapKey(context);
             }
         }
     }


     @Override
     public boolean isAliasableNode(){
         return true;
     }
 }
	/*
	* Copyright (c) 1998, 2021 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 v. 2.0 which is available at
	* http://www.eclipse.org/legal/epl-2.0,
	* or the Eclipse Distribution License v. 1.0 which is available at
	* http://www.eclipse.org/org/documents/edl-v10.php.
	*
	* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
	*/

	// Contributors:
	// Oracle - initial API and implementation from Oracle TopLink
	package org.eclipse.persistence.internal.jpa.parsing;

	import java.util.ArrayList;
	import java.util.Iterator;
	import java.util.List;

	// TopLink imports
	import org.eclipse.persistence.exceptions.JPQLException;
	import org.eclipse.persistence.expressions.Expression;
	import org.eclipse.persistence.expressions.ExpressionBuilder;
	import org.eclipse.persistence.internal.expressions.ConstantExpression;
	import org.eclipse.persistence.queries.ObjectLevelReadQuery;
	import org.eclipse.persistence.queries.ReportQuery;

	/**
	* INTERNAL
	* <p><b>Purpose</b>: The node that represents typed variables, local variables, remote variables and TYPE constants.
	*
	* @author Jon Driscoll and Joel Lucuik
	* @since TopLink 4.0
	*/
	public class VariableNode extends Node implements AliasableNode {

	/** */
	private String variableName;

	/** */
	private String canonicalName;

	/ if this represents a type constant, this value will be populated by validate /
	private Object classConstant = null;

	/**
	* VariableNode constructor comment.
	*/
	public VariableNode() {
	super();
	}

	public VariableNode(String newVariableName) {
	setVariableName(newVariableName);
	}

	public String getVariableName() {
	return variableName;
	}

	public void setVariableName(String newVariableName) {
	variableName = newVariableName;
	canonicalName = IdentificationVariableDeclNode.calculateCanonicalName(newVariableName);
	}

	/** */
	public String getCanonicalVariableName() {
	return canonicalName;
	}

	/**
	* INTERNAL
	* Is this node a VariableNode
	*/
	@Override
	public boolean isVariableNode() {
	return true;
	}

	/**
	* INTERNAL
	* Apply this node to the passed query
	*/
	@Override
	public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext generationContext) {
	String name = getCanonicalVariableName();
	if (theQuery instanceof ReportQuery) {
	ReportQuery reportQuery = (ReportQuery)theQuery;
	Expression expression = generationContext.expressionFor(name);
	if (expression == null) {
	expression = generateExpression(generationContext);
	}
	addAttributeWithFetchJoins(reportQuery, expression, generationContext);
	} else {
	addFetchJoins(theQuery, generationContext);
	}
	}

	/**
	* INTERNAL
	* Add the variable as ReportQuery item. The method checks for any JOIN
	* FETCH nodes of the current variable and adds them as part of the
	* ReportQuery item.
	*/
	private void addAttributeWithFetchJoins(ReportQuery reportQuery,
	Expression expression,
	GenerationContext context) {
	String name = getCanonicalVariableName();
	List<Node> fetchJoinNodes = context.getParseTreeContext().getFetchJoins(name);
	if (fetchJoinNodes == null) {
	reportQuery.addAttribute(name, expression);
	} else {
	List<Expression> fetchJoinExprs = new ArrayList<>(fetchJoinNodes.size());
	for (Iterator<Node> i = fetchJoinNodes.iterator(); i.hasNext(); ) {
	Node node = i.next();
	fetchJoinExprs.add(node.generateExpression(context));
	}
	reportQuery.addItem(name, expression, fetchJoinExprs);
	}
	}

	/**
	* INTERNAL
	* Check for any JOIN FETCH nodes of the current variable and add them as
	* joined attributes. This method is called in case of a non ReportQuery
	* instance.
	*/
	private void addFetchJoins(ObjectLevelReadQuery theQuery,
	GenerationContext context) {
	String name = getCanonicalVariableName();
	List<Node> fetchJoinNodes = context.getParseTreeContext().getFetchJoins(name);
	if (fetchJoinNodes != null) {
	for (Iterator<Node> i = fetchJoinNodes.iterator(); i.hasNext(); ) {
	Node node = i.next();
	theQuery.addJoinedAttribute(node.generateExpression(context));
	}
	}
	}

	/**
	* INTERNAL
	* This node represent an unqualified field access in the case the method
	* is called and the variableName is not defined as identification variable.
	* The method returns a DotNode representing a qualified field access with
	* the base variable as left child node. The right child node is an
	* AttributeNode using the variableName as field name.
	*/
	@Override
	public Node qualifyAttributeAccess(ParseTreeContext context) {
	return context.isVariable(variableName) ? this :
	(Node)context.getNodeFactory().newQualifiedAttribute(
	getLine(), getColumn(), context.getBaseVariable(), variableName);
	}

	/**
	* INTERNAL
	* Validate node and calculate its type.
	*/
	@Override
	public void validate(ParseTreeContext context) {
	TypeHelper typeHelper = context.getTypeHelper();
	classConstant = typeHelper.resolveSchema(variableName);
	if (classConstant != null){
	setType(Class.class);
	return;
	}
	String name = getCanonicalVariableName();
	if (context.isRangeVariable(name)) {
	String schema = context.schemaForVariable(name);
	setType(typeHelper.resolveSchema(schema));
	} else {
	Node path = context.pathForVariable(name);
	if (path == null) {
	throw JPQLException.aliasResolutionException(
	context.getQueryInfo(), getLine(), getColumn(), name);
	} else {
	setType(path.getType());
	}
	}
	context.usedVariable(name);
	if (context.isDeclaredInOuterScope(name)) {
	context.registerOuterScopeVariable(name);
	}
	}

	public Expression generateBaseBuilderExpression(GenerationContext context) {
	//create builder, and add it, and answer it
	//BUG 3106877: Need to create builder using the actual class (if using parallel expressions)
	return new ExpressionBuilder(this.resolveClass(context));
	}

	@Override
	public Expression generateExpression(GenerationContext generationContext) {
	Expression myExpression = null;
	String name = getCanonicalVariableName();

	//is there a cached Expression?
	myExpression = generationContext.expressionFor(name);
	if (myExpression != null) {
	return myExpression;
	}

	//Either I have an alias type, or I'm an IN declaration
	if (classConstant != null){
	myExpression = new ConstantExpression(classConstant, generationContext.getBaseExpression());
	} else if (generationContext.getParseTreeContext().isRangeVariable(name)) {
	myExpression = generateBaseBuilderExpression(generationContext);
	} else {
	myExpression = generateExpressionForAlias(generationContext);
	}

	generationContext.addExpression(myExpression, name);
	return myExpression;
	}

	public Expression generateExpressionForAlias(GenerationContext context) {
	// BUG 3105651: Verify if we need to resolve this alias, or just use
	// an empty ExpressionBuilder. See OrderByItemNode.generateExpression()
	// for more details
	if (context.getParseTree().getQueryNode().isSelectNode() && context.shouldCheckSelectNodeBeforeResolving() && (((SelectNode)context.getParseTree().getQueryNode()).isSelected(this.getCanonicalVariableName()))) {
	return new ExpressionBuilder();
	}

	Node nodeForAlias = getNodeForAlias(context);

	//assume that if there is no node available for the given variable, then
	//there must be an alias mismatch. Assume they know their attribute names better
	//than their alias names. - JGL
	if (nodeForAlias == null) {
	throw JPQLException.aliasResolutionException(
	context.getParseTreeContext().getQueryInfo(),
	getLine(), getColumn(), getVariableName());
	}

	//create builder, and answer it
	return nodeForAlias.generateExpression(context);
	}

	public Node getNodeForAlias(GenerationContext context) {
	//Node node = context.getParseTreeContext().nodeForIdentifier(getCanonicalVariableName());
	//return node != null ? ((IdentificationVariableDeclNode)node).getPath() : null;
	return context.getParseTreeContext().pathForVariable(getCanonicalVariableName());
	}

	/**
	* isAlias: Answer true if this variable represents an alias in the FROM clause.
	* i.e. "FROM Employee emp" declares "emp" as an alias
	*/
	public boolean isAlias(GenerationContext context) {
	return isAlias(context.getParseTreeContext());
	}

	public boolean isAlias(ParseTreeContext context) {
	String classNameForAlias = context.schemaForVariable(getCanonicalVariableName());
	return classNameForAlias != null;
	}

	/**
	* resolveClass: Answer the class which corresponds to my variableName. This is the class for
	* an alias, where the variableName is registered to an alias.
	*/
	@Override
	public Class<?> resolveClass(GenerationContext generationContext) {
	Class<?> clazz = null;
	String name = getCanonicalVariableName();
	ParseTreeContext context = generationContext.getParseTreeContext();
	if (context.isRangeVariable(name)) {
	String schema = context.schemaForVariable(name);
	clazz = context.classForSchemaName(schema, generationContext);
	} else {
	DotNode path = (DotNode)context.pathForVariable(name);
	if (path == null) {
	throw JPQLException.aliasResolutionException(
	context.getQueryInfo(), getLine(), getColumn(), name);
	} else {
	clazz = path.resolveClass(generationContext);
	}
	}
	return clazz;
	}

	@Override
	public String toString(int indent) {
	StringBuilder buffer = new StringBuilder();
	toStringIndent(indent, buffer);
	buffer.append(toStringDisplayName()).append("[").append(getVariableName()).append("]");
	return buffer.toString();
	}

	/**
	* INTERNAL
	* Get the string representation of this node.
	*/
	@Override
	public String getAsString() {
	return getVariableName();
	}

	public Object getTypeForMapKey(ParseTreeContext context){
	String name = getCanonicalVariableName();
	if (context.isRangeVariable(name)) {
	throw JPQLException.variableCannotHaveMapKey(context.getQueryInfo(), getLine(), getColumn(), name);
	} else {
	DotNode path = (DotNode)context.pathForVariable(name);
	if (path == null) {
	throw JPQLException.aliasResolutionException(
	context.getQueryInfo(), getLine(), getColumn(), name);
	} else {
	return path.getTypeForMapKey(context);
	}
	}
	}


	@Override
	public boolean isAliasableNode(){
	return true;
	}
	}