de.cuioss.tools.collect.PartialArrayList Maven / Gradle / Ivy
/*
* Copyright 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 de.cuioss.tools.collect;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import lombok.EqualsAndHashCode;
import lombok.Getter;
import lombok.ToString;
/**
*
Overview
Default implementation of {@link PartialCollection} based
* on {@link ArrayList}.
* Usage
*
* See {@link PartialArrayList#of(List, int)}
*
*
* @param at least {@link Serializable}
*/
@EqualsAndHashCode(callSuper = true)
@ToString(callSuper = true)
public class PartialArrayList extends ArrayList implements PartialCollection {
private static final long serialVersionUID = -7548645400982124555L;
@Getter
private final boolean moreAvailable;
/**
* Default constructor.
*
* @param list the list of entities to store.
* @param moreAvailable the flag to store.
*/
public PartialArrayList(Collection list, boolean moreAvailable) {
super(list);
this.moreAvailable = moreAvailable;
}
/**
* Static constructor for an empty instance.
*
* @param
* @return an empty {@link PartialArrayList}.
*/
public static PartialArrayList emptyList() {
return new PartialArrayList<>(Collections.emptyList(), false);
}
/**
* Convenience method for creating a {@link PartialArrayList} as sublist for the
* given collection with setting the {@link PartialCollection#isMoreAvailable()}
* automatically
*
* @param full the complete List to be wrapped, may be larger than the limit.
* If so, a sublist will be used.
* @param limit to be checked against
*
* @param identifying the type of contained elements
* @return a newly created {@link PartialArrayList}.
*/
public static PartialArrayList of(List full, int limit) {
if (MoreCollections.isEmpty(full)) {
return emptyList();
}
var actualSize = full.size();
if (actualSize <= limit) {
return new PartialArrayList<>(full, false);
}
return new PartialArrayList<>(full.subList(0, limit), true);
}
}