001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * // Copyright (c) 1998, 2007, Oracle. All rights reserved.
005: *
006: *
007: * The contents of this file are subject to the terms of either the GNU
008: * General Public License Version 2 only ("GPL") or the Common Development
009: * and Distribution License("CDDL") (collectively, the "License"). You
010: * may not use this file except in compliance with the License. You can obtain
011: * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
012: * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
013: * language governing permissions and limitations under the License.
014: *
015: * When distributing the software, include this License Header Notice in each
016: * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
017: * Sun designates this particular file as subject to the "Classpath" exception
018: * as provided by Sun in the GPL Version 2 section of the License file that
019: * accompanied this code. If applicable, add the following below the License
020: * Header, with the fields enclosed by brackets [] replaced by your own
021: * identifying information: "Portions Copyrighted [year]
022: * [name of copyright owner]"
023: *
024: * Contributor(s):
025: *
026: * If you wish your version of this file to be governed by only the CDDL or
027: * only the GPL Version 2, indicate your decision by adding "[Contributor]
028: * elects to include this software in this distribution under the [CDDL or GPL
029: * Version 2] license." If you don't indicate a single choice of license, a
030: * recipient has the option to distribute your version of this file under
031: * either the CDDL, the GPL Version 2 or to extend the choice of license to
032: * its licensees as provided above. However, if you add GPL Version 2 code
033: * and therefore, elected the GPL Version 2 license, then the option applies
034: * only if the new code is made subject to such option by the copyright
035: * holder.
036: */
037: package oracle.toplink.essentials.internal.parsing;
038:
039: import oracle.toplink.essentials.expressions.*;
040: import oracle.toplink.essentials.exceptions.EJBQLException;
041:
042: /**
043: * INTERNAL
044: * <p><b>Purpose</b>: Represent an '=' in EJBQL
045: * <p><b>Responsibilities</b>:<ul>
046: * <li> Generate the correct expression for an '=' in EJBQL
047: * </ul>
048: * @author Jon Driscoll and Joel Lucuik
049: * @since TopLink 4.0
050: */
051: public class EqualsNode extends BinaryOperatorNode {
052:
053: /**
054: * EqualsNode constructor comment.
055: */
056: public EqualsNode() {
057: super ();
058: }
059:
060: /**
061: * INTERNAL
062: * Validate node and calculates its type.
063: */
064: public void validate(ParseTreeContext context) {
065: super .validate(context);
066: TypeHelper typeHelper = context.getTypeHelper();
067: Object leftType = left.getType();
068: Object rightType = right.getType();
069: if (typeHelper.isEnumType(leftType)
070: && !typeHelper.isEnumType(rightType)) {
071: throw EJBQLException.invalidEnumEqualExpression(context
072: .getQueryInfo(), getLine(), getColumn(), typeHelper
073: .getTypeName(leftType), typeHelper
074: .getTypeName(rightType));
075: } else if (typeHelper.isEnumType(rightType)
076: && !typeHelper.isEnumType(leftType)) {
077: throw EJBQLException.invalidEnumEqualExpression(context
078: .getQueryInfo(), getLine(), getColumn(), typeHelper
079: .getTypeName(rightType), typeHelper
080: .getTypeName(leftType));
081: }
082:
083: setType(typeHelper.getBooleanType());
084: }
085:
086: /**
087: * Resolve the expression. The steps are:
088: * 1. Set the expressionBuilder for the left and right nodes
089: * 2. Generate the expression for the left node
090: * 3. Add the .equals to the where clause returned from step 2
091: * 4. Generate the expression for the right side and use it as the parameter for the .equals()
092: * 5. Return the completed where clause to the caller
093: */
094: public Expression generateExpression(GenerationContext context) {
095: Expression whereClause = getLeft().generateExpression(context);
096: whereClause = whereClause.equal(getRight().generateExpression(
097: context));
098: return whereClause;
099: }
100:
101: /**
102: * INTERNAL
103: * Get the string representation of this node.
104: */
105: public String getAsString() {
106: return left.getAsString() + " = " + right.getAsString();
107: }
108: }
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