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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.Condition;
import org.springframework.data.relational.core.sql.Expression;
import org.springframework.data.relational.core.sql.Like;
import org.springframework.data.relational.core.sql.Visitable;
import org.springframework.lang.Nullable;
/**
* {@link org.springframework.data.relational.core.sql.Visitor} rendering comparison {@link Condition}. Uses a
* {@link RenderTarget} to call back for render results.
*
* @author Mark Paluch
* @see Like
* @since 1.1
*/
class LikeVisitor extends FilteredSubtreeVisitor {
private final Like like;
private final RenderContext context;
private final RenderTarget target;
private final StringBuilder part = new StringBuilder();
private @Nullable PartRenderer current;
LikeVisitor(Like condition, RenderContext context, RenderTarget target) {
super(it -> it == condition);
this.like = condition;
this.context = context;
this.target = target;
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.FilteredSubtreeVisitor#enterNested(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation enterNested(Visitable segment) {
if (segment instanceof Expression) {
ExpressionVisitor visitor = new ExpressionVisitor(context);
current = visitor;
return Delegation.delegateTo(visitor);
}
if (segment instanceof Condition) {
ConditionVisitor visitor = new ConditionVisitor(context);
current = visitor;
return Delegation.delegateTo(visitor);
}
throw new IllegalStateException("Cannot provide visitor for " + segment);
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.FilteredSubtreeVisitor#leaveNested(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation leaveNested(Visitable segment) {
if (current != null) {
if (part.length() != 0) {
part.append(' ');
if (like.isNegated()) {
part.append("NOT ");
}
part.append("LIKE ");
}
part.append(current.getRenderedPart());
current = null;
}
return super.leaveNested(segment);
}
/*
* (non-Javadoc)
* @see org.springframework.data.relational.core.sql.render.FilteredSubtreeVisitor#leaveMatched(org.springframework.data.relational.core.sql.Visitable)
*/
@Override
Delegation leaveMatched(Visitable segment) {
target.onRendered(part);
return super.leaveMatched(segment);
}
}