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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.persistence.criteria;
import javax.persistence.criteria.Expression;
import javax.persistence.criteria.Order;
/**
* Ordering clause of a criteria query.
*
* @author Pinaki Poddar
*
*/
class OrderImpl implements Order, CriteriaExpression {
private boolean _ascending;
private final ExpressionImpl<?> e;
public OrderImpl(Expression<?> e, boolean asc) {
this.e = (ExpressionImpl<?>) e;
_ascending = asc;
}
public OrderImpl(Expression<?> e) {
this(e, true);
}
@Override
public ExpressionImpl<?> getExpression() {
return e;
}
@Override
public boolean isAscending() {
return _ascending;
}
@Override
public Order reverse() {
_ascending = !_ascending;
return this;
}
@Override
public void acceptVisit(CriteriaExpressionVisitor visitor) {
if (!visitor.isVisited(this)) {
visitor.enter(this);
visitor.exit(this);
}
}
@Override
public StringBuilder asValue(AliasContext q) {
return (e.isAutoAliased() ? e.asValue(q) : new StringBuilder(e.getAlias()))
.append(_ascending ? "" : " DESC");
}
@Override
public StringBuilder asProjection(AliasContext q) {
throw new IllegalStateException(this + " can not be rendered as projection");
}
@Override
public StringBuilder asVariable(AliasContext q) {
throw new IllegalStateException(this + " can not be rendered as variable");
}
}