io.evitadb.comparator.NullsFirstComparatorWrapper Maven / Gradle / Ivy
/*
*
* _ _ ____ ____
* _____ _(_) |_ __ _| _ \| __ )
* / _ \ \ / / | __/ _` | | | | _ \
* | __/\ V /| | || (_| | |_| | |_) |
* \___| \_/ |_|\__\__,_|____/|____/
*
* Copyright (c) 2023
*
* Licensed under the Business Source License, Version 1.1 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://github.com/FgForrest/evitaDB/blob/master/LICENSE
*
* 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 io.evitadb.comparator;
import lombok.RequiredArgsConstructor;
import javax.annotation.Nonnull;
import java.io.Serial;
import java.io.Serializable;
import java.util.Comparator;
/**
* This comparator implementation wraps any other comparator and ensures that null values are always sorted first.
*
* @author Jan Novotný ([email protected]), FG Forrest a.s. (c) 2023
*/
@RequiredArgsConstructor
public class NullsFirstComparatorWrapper> implements Comparator, Serializable {
@Serial private static final long serialVersionUID = 4800374022912778678L;
@Nonnull private final Comparator delegate;
@Override
public int compare(T o1, T o2) {
if (o1 == null && o2 != null) {
return -1;
} else if (o2 == null && o1 != null) {
return 1;
} else if (o1 == null) {
return 0;
} else {
return delegate.compare(o1, o2);
}
}
}