62 lines
1.4 KiB
Java
62 lines
1.4 KiB
Java
/*
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* Copyright 2021 Paul Schaub.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package sop.util;
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/**
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* Backport of java.util.Optional for older Android versions.
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*
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* @param <T> item type
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*/
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public class Optional<T> {
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private final T item;
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public Optional() {
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this(null);
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}
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public Optional(T item) {
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this.item = item;
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}
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public static <T> Optional<T> of(T item) {
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if (item == null) {
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throw new NullPointerException("Item cannot be null.");
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}
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return new Optional<>(item);
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}
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public static <T> Optional<T> ofNullable(T item) {
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return new Optional<>(item);
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}
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public static <T> Optional<T> ofEmpty() {
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return new Optional<>(null);
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}
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public T get() {
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return item;
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}
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public boolean isPresent() {
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return item != null;
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}
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public boolean isEmpty() {
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return item == null;
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}
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}
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