| /* |
| * 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: |
| // tware - initial implementation as part of JPA 2.0 RI |
| package org.eclipse.persistence.internal.jpa.parsing; |
| |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.eclipse.persistence.expressions.Expression; |
| import org.eclipse.persistence.queries.ObjectLevelReadQuery; |
| import org.eclipse.persistence.queries.ReportQuery; |
| |
| /** |
| * INTERNAL |
| * <p><b>Purpose</b>: Represent an CASE statement in EJBQL |
| * <p><b>Responsibilities</b>:<ul> |
| * <li> Generate the correct expression for an CASE in EJBQL |
| * </ul> |
| * @author tware |
| * @since EclipseLink 1.2 |
| */ |
| public class CaseNode extends Node implements AliasableNode { |
| |
| private List<Node> whenClauses = null; |
| |
| |
| public CaseNode(){ |
| super(); |
| } |
| |
| /** |
| * INTERNAL |
| * Apply this node to the passed query |
| */ |
| @Override |
| public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext generationContext) { |
| if (theQuery instanceof ReportQuery) { |
| ReportQuery reportQuery = (ReportQuery)theQuery; |
| Expression expression = generateExpression(generationContext); |
| reportQuery.addAttribute("Case", expression, (Class<?>)getType()); |
| } |
| } |
| |
| /** |
| * INTERNAL |
| * Generate the a new EclipseLink TableEntryExpression for this node. |
| */ |
| @Override |
| public Expression generateExpression(GenerationContext context) { |
| Map<Expression, Expression> whenClauseMap = new LinkedHashMap<>(whenClauses.size()); |
| Iterator<Node> i = whenClauses.iterator(); |
| while (i.hasNext()){ |
| WhenThenNode clause = (WhenThenNode)i.next(); |
| whenClauseMap.put(clause.generateExpressionForWhen(context), clause.generateExpressionForThen(context)); |
| } |
| |
| Expression whereClause = null; |
| if (getLeft() == null){ |
| whereClause = context.getBaseExpression().caseStatement(whenClauseMap, getRight().generateExpression(context)); |
| } else { |
| whereClause = getLeft().generateExpression(context).caseStatement(whenClauseMap, getRight().generateExpression(context)); |
| } |
| return whereClause; |
| } |
| |
| @Override |
| public void validate(ParseTreeContext context) { |
| TypeHelper typeHelper = context.getTypeHelper(); |
| if (left != null){ |
| left.validate(context); |
| } |
| right.validate(context); |
| Iterator<Node> i = whenClauses.iterator(); |
| Object type = null; |
| while (i.hasNext()){ |
| Node node = i.next(); |
| node.validate(context); |
| if (type == null){ |
| type = node.getType(); |
| } else if (!type.equals(node.getType())){ |
| type = Object.class; |
| } |
| } |
| if (getRight().getType() != type){ |
| type = typeHelper.getObjectType(); |
| } |
| setType(type); |
| } |
| |
| |
| public List<Node> getWhenClauses() { |
| return whenClauses; |
| } |
| |
| public void setWhenClauses(List<Node> whenClauses) { |
| this.whenClauses = whenClauses; |
| } |
| |
| @Override |
| public boolean isAliasableNode(){ |
| return true; |
| } |
| } |