org.springframework.data.relational.core.sql.render.OrderByClauseVisitor Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of spring-data-relational Show documentation
Show all versions of spring-data-relational Show documentation
Spring Data Relational support
/*
* Copyright 2019-2023 the original author or authors.
*
* Licensed 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
*
* https://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.springframework.data.relational.core.sql.render;
import org.springframework.data.relational.core.sql.Column;
import org.springframework.data.relational.core.sql.OrderByField;
import org.springframework.data.relational.core.sql.Visitable;
/**
* {@link PartRenderer} for {@link OrderByField}s.
*
* @author Mark Paluch
* @author Jens Schauder
* @author Chirag Tailor
* @since 1.1
*/
class OrderByClauseVisitor extends TypedSubtreeVisitor implements PartRenderer {
private final RenderContext context;
private final StringBuilder builder = new StringBuilder();
private boolean first = true;
OrderByClauseVisitor(RenderContext context) {
this.context = context;
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.TypedSubtreeVisitor#enterMatched(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation enterMatched(OrderByField segment) {
if (!first) {
builder.append(", ");
}
first = false;
return super.enterMatched(segment);
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.TypedSubtreeVisitor#leaveMatched(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation leaveMatched(OrderByField segment) {
if (segment.getDirection() != null) {
builder.append(" ") //
.append(segment.getDirection());
}
String nullPrecedence = context.getSelectRenderContext().evaluateOrderByNullHandling(segment.getNullHandling());
if (!nullPrecedence.isEmpty()) {
builder.append(" ") //
.append(nullPrecedence);
}
return Delegation.leave();
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.TypedSubtreeVisitor#leaveNested(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation leaveNested(Visitable segment) {
if (segment instanceof Column) {
builder.append(NameRenderer.fullyQualifiedReference(context, (Column) segment));
}
return super.leaveNested(segment);
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.PartRenderer#getRenderedPart()
*/
@Override
public CharSequence getRenderedPart() {
return builder;
}
}