oracle.toplink.essentials.internal.expressions.ExpressionNormalizer Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* // Copyright (c) 1998, 2007, Oracle. All rights reserved.
*
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package oracle.toplink.essentials.internal.expressions;
import java.util.*;
import oracle.toplink.essentials.expressions.*;
import oracle.toplink.essentials.internal.sessions.AbstractSession;
/**
* This is used during the normalization process to allow for a single main expression traversal.
*/
public class ExpressionNormalizer {
/** A new root expression can be made from joins being added to the original expression. */
protected Expression additionalExpression;
/** The statement being normalized. */
protected SQLSelectStatement statement;
/** Subselect expressions found in the course of normalization. */
protected Vector subSelectExpressions;
/** The session being normalized in. */
protected AbstractSession session;
public ExpressionNormalizer(SQLSelectStatement statement) {
this.statement = statement;
}
public void addAdditionalExpression(Expression theExpression) {
// This change puts a null check into every call, but is printing additional
// expressions in a meaningfull order worth it?
additionalExpression = (additionalExpression == null) ? theExpression : additionalExpression.and(theExpression);
}
/**
* INTERNAL:
* Remember this subselect so that it can be normalized after the enclosing
* select statement is.
*/
public void addSubSelectExpression(SubSelectExpression subSelectExpression) {
if (subSelectExpressions == null) {
subSelectExpressions = new Vector(1);
}
subSelectExpressions.add(subSelectExpression);
}
public Expression getAdditionalExpression() {
return additionalExpression;
}
public AbstractSession getSession() {
return session;
}
public SQLSelectStatement getStatement() {
return statement;
}
/**
* INTERNAL:
* Were subselect expressions found while normalizing the selection criteria?
* Assumes underlying collection is initialized on first add.
*/
public boolean encounteredSubSelectExpressions() {
return (subSelectExpressions != null);
}
/**
* INTERNAL:
* Normalize all subselect expressions found in the course of normalizing the
* enclosing query.
* This method allows one to completely normalize the parent statement first
* (which should treat its sub selects as black boxes), and then normalize the
* subselects (which require full knowledge of the enclosing statement).
* This should make things clearer too,
* Assumes encounteredSubSelectExpressions() true.
* For CR#4223.
*/
public void normalizeSubSelects(Dictionary clonedExpressions) {
for (Enumeration enumtr = subSelectExpressions.elements(); enumtr.hasMoreElements();) {
SubSelectExpression next = (SubSelectExpression)enumtr.nextElement();
next.normalizeSubSelect(this, clonedExpressions);
}
}
public void setAdditionalExpression(Expression additionalExpression) {
this.additionalExpression = additionalExpression;
}
public void setSession(AbstractSession session) {
this.session = session;
}
public void setStatement(SQLSelectStatement statement) {
this.statement = statement;
}
}