oracle.toplink.essentials.internal.expressions.ExpressionNormalizer Maven / Gradle / Ivy
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*
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* glassfish/bootstrap/legal/CDDLv1.0.txt or
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// Copyright (c) 1998, 2007, Oracle. All rights reserved.
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;
}
}