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@@ -1,365 +0,0 @@
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-/*
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- * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
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- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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- *
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- * This code is free software; you can redistribute it and/or modify it
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- * under the terms of the GNU General Public License version 2 only, as
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- * published by the Free Software Foundation. Oracle designates this
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- * particular file as subject to the "Classpath" exception as provided
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- * by Oracle in the LICENSE file that accompanied this code.
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- *
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- * This code is distributed in the hope that it will be useful, but WITHOUT
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- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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- * version 2 for more details (a copy is included in the LICENSE file that
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- * accompanied this code).
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- *
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- * You should have received a copy of the GNU General Public License version
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- * 2 along with this work; if not, write to the Free Software Foundation,
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- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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- *
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- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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- * or visit www.oracle.com if you need additional information or have any
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- * questions.
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- */
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-package com.nextcloud.java.util;
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-
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-import com.nextcloud.java.util.function.Predicate;
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-
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-import java.util.NoSuchElementException;
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-
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-import androidx.core.util.Consumer;
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-import androidx.core.util.ObjectsCompat;
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-import androidx.core.util.Supplier;
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-import kotlin.jvm.functions.Function1;
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-
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-/**
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- * This class is backported from Java 8 to be used on older Android API levels.
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- * It uses available interfaces from Kotlin and androidx. It is semantically
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- * identical with Java 8 API, allowing smooth migration when those APIs become
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- * available.
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- *
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- * A container object which may or may not contain a non-null value.
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- * If a value is present, {@code isPresent()} will return {@code true} and
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- * {@code get()} will return the value.
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- *
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- * <p>Additional methods that depend on the presence or absence of a contained
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- * value are provided, such as {@link #orElse(java.lang.Object) orElse()}
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- * (return a default value if value not present) and
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- * {@link #ifPresent(Consumer) ifPresent()} (execute a block
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- * of code if the value is present).
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- */
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-public final class Optional<T> {
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- /**
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- * Common instance for {@code empty()}.
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- */
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- private static final Optional<?> EMPTY = new Optional<>();
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-
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- /**
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- * If non-null, the value; if null, indicates no value is present
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- */
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- private final T value;
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-
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- /**
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- * Constructs an empty instance.
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- *
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- * @implNote Generally only one empty instance, {@link Optional#EMPTY},
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- * should exist per VM.
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- */
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- private Optional() {
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- this.value = null;
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- }
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-
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- /**
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- * Returns an empty {@code Optional} instance. No value is present for this
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- * Optional.
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- *
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- * @apiNote Though it may be tempting to do so, avoid testing if an object
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- * is empty by comparing with {@code ==} against instances returned by
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- * {@code Option.empty()}. There is no guarantee that it is a singleton.
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- * Instead, use {@link #isPresent()}.
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- *
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- * @param <T> Type of the non-existent value
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- * @return an empty {@code Optional}
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- */
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- @SuppressWarnings("unchecked")
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- public static<T> Optional<T> empty() {
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- return (Optional<T>) EMPTY;
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- }
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-
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- /**
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- * Constructs an instance with the value present.
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- *
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- * @param value the non-null value to be present
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- * @throws NullPointerException if value is null
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- */
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- private Optional(T value) {
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- if (value == null) {
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- throw new NullPointerException();
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- }
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- this.value = value;
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- }
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-
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- /**
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- * Returns an {@code Optional} with the specified present non-null value.
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- *
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- * @param <T> the class of the value
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- * @param value the value to be present, which must be non-null
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- * @return an {@code Optional} with the value present
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- * @throws NullPointerException if value is null
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- */
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- public static <T> Optional<T> of(T value) {
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- return new Optional<>(value);
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- }
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-
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- /**
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- * Returns an {@code Optional} describing the specified value, if non-null,
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- * otherwise returns an empty {@code Optional}.
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- *
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- * @param <T> the class of the value
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- * @param value the possibly-null value to describe
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- * @return an {@code Optional} with a present value if the specified value
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- * is non-null, otherwise an empty {@code Optional}
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- */
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- public static <T> Optional<T> ofNullable(T value) {
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- return value == null ? empty() : of(value);
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- }
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-
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- /**
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- * If a value is present in this {@code Optional}, returns the value,
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- * otherwise throws {@code NoSuchElementException}.
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- *
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- * @return the non-null value held by this {@code Optional}
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- * @throws NoSuchElementException if there is no value present
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- *
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- * @see Optional#isPresent()
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- */
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- public T get() {
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- if (value == null) {
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- throw new NoSuchElementException("No value present");
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- }
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- return value;
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- }
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-
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- /**
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- * Return {@code true} if there is a value present, otherwise {@code false}.
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- *
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- * @return {@code true} if there is a value present, otherwise {@code false}
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- */
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- public boolean isPresent() {
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- return value != null;
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- }
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-
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- /**
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- * If a value is present, invoke the specified consumer with the value,
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- * otherwise do nothing.
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- *
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- * @param consumer block to be executed if a value is present
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- * @throws NullPointerException if value is present and {@code consumer} is
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- * null
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- */
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- public void ifPresent(Consumer<? super T> consumer) {
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- if (value != null) {
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- consumer.accept(value);
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- }
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- }
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-
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- /**
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- * If a value is present, and the value matches the given predicate,
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- * return an {@code Optional} describing the value, otherwise return an
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- * empty {@code Optional}.
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- *
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- * @param predicate a predicate to apply to the value, if present
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- * @return an {@code Optional} describing the value of this {@code Optional}
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- * if a value is present and the value matches the given predicate,
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- * otherwise an empty {@code Optional}
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- * @throws NullPointerException if the predicate is null
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- */
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- public Optional<T> filter(Predicate<? super T> predicate) {
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- if (predicate == null) {
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- throw new NullPointerException();
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- }
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- if (!isPresent()) {
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- return this;
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- } else {
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- return predicate.test(value) ? this : empty();
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- }
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- }
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-
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- /**
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- * If a value is present, apply the provided mapping function to it,
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- * and if the result is non-null, return an {@code Optional} describing the
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- * result. Otherwise return an empty {@code Optional}.
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- *
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- * @apiNote This method supports post-processing on optional values, without
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- * the need to explicitly check for a return status. For example, the
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- * following code traverses a stream of file names, selects one that has
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- * not yet been processed, and then opens that file, returning an
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- * {@code Optional<FileInputStream>}:
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- *
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- * <pre>{@code
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- * Optional<FileInputStream> fis =
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- * names.stream().filter(name -> !isProcessedYet(name))
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- * .findFirst()
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- * .map(name -> new FileInputStream(name));
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- * }</pre>
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- *
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- * Here, {@code findFirst} returns an {@code Optional<String>}, and then
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- * {@code map} returns an {@code Optional<FileInputStream>} for the desired
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- * file if one exists.
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- *
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- * @param <U> The type of the result of the mapping function
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- * @param mapper a mapping function to apply to the value, if present
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- * @return an {@code Optional} describing the result of applying a mapping
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- * function to the value of this {@code Optional}, if a value is present,
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- * otherwise an empty {@code Optional}
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- * @throws NullPointerException if the mapping function is null
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- */
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- public<U> Optional<U> map(Function1<? super T, ? extends U> mapper) {
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- if (mapper == null) {
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- throw new NullPointerException();
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- }
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- if (!isPresent()) {
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- return empty();
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- } else {
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- return Optional.ofNullable(mapper.invoke(value));
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- }
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- }
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-
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- /**
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- * If a value is present, apply the provided {@code Optional}-bearing
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- * mapping function to it, return that result, otherwise return an empty
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- * {@code Optional}. This method is similar to {@link #map(Function1)},
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- * but the provided mapper is one whose result is already an {@code Optional},
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- * and if invoked, {@code flatMap} does not wrap it with an additional
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- * {@code Optional}.
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- *
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- * @param <U> The type parameter to the {@code Optional} returned by
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- * @param mapper a mapping function to apply to the value, if present
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- * the mapping function
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- * @return the result of applying an {@code Optional}-bearing mapping
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- * function to the value of this {@code Optional}, if a value is present,
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- * otherwise an empty {@code Optional}
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- * @throws NullPointerException if the mapping function is null or returns
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- * a null result
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- */
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- public<U> Optional<U> flatMap(Function1<? super T, Optional<U>> mapper) {
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- if(mapper == null) {
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- throw new NullPointerException();
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- }
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- if (!isPresent()) {
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- return empty();
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- } else {
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- Optional<U> u = mapper.invoke(value);
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- if (u == null) {
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- throw new NullPointerException();
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- }
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- return u;
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- }
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- }
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-
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- /**
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- * Return the value if present, otherwise return {@code other}.
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- *
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- * @param other the value to be returned if there is no value present, may
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- * be null
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- * @return the value, if present, otherwise {@code other}
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- */
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- public T orElse(T other) {
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- return value != null ? value : other;
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- }
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-
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- /**
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- * Return the value if present, otherwise invoke {@code other} and return
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- * the result of that invocation.
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- *
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- * @param other a {@code Supplier} whose result is returned if no value
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- * is present
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- * @return the value if present otherwise the result of {@code other.get()}
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- * @throws NullPointerException if value is not present and {@code other} is
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- * null
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- */
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- public T orElseGet(Supplier<? extends T> other) {
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- return value != null ? value : other.get();
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- }
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-
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- /**
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- * Return the contained value, if present, otherwise throw an exception
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- * to be created by the provided supplier.
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- *
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- * @apiNote A method reference to the exception constructor with an empty
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- * argument list can be used as the supplier. For example,
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- * {@code IllegalStateException::new}
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- *
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- * @param <X> Type of the exception to be thrown
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- * @param exceptionSupplier The supplier which will return the exception to
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- * be thrown
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- * @return the present value
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- * @throws X if there is no value present
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- * @throws NullPointerException if no value is present and
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- * {@code exceptionSupplier} is null
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- */
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- public <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
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- if (value != null) {
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- return value;
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- } else {
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- throw exceptionSupplier.get();
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- }
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- }
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-
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- /**
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- * Indicates whether some other object is "equal to" this Optional. The
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- * other object is considered equal if:
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- * <ul>
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- * <li>it is also an {@code Optional} and;
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- * <li>both instances have no value present or;
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- * <li>the present values are "equal to" each other via {@code equals()}.
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- * </ul>
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- *
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- * @param obj an object to be tested for equality
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- * @return {code true} if the other object is "equal to" this object
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- * otherwise {@code false}
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- */
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- @Override
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- public boolean equals(Object obj) {
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- if (this == obj) {
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- return true;
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- }
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-
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- if (!(obj instanceof Optional)) {
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- return false;
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- }
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-
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- Optional<?> other = (Optional<?>) obj;
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- return ObjectsCompat.equals(value, other.value);
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- }
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-
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- /**
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- * Returns the hash code value of the present value, if any, or 0 (zero) if
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- * no value is present.
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- *
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- * @return hash code value of the present value or 0 if no value is present
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- */
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- @Override
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- public int hashCode() {
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- return ObjectsCompat.hashCode(value);
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- }
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-
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- /**
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- * Returns a non-empty string representation of this Optional suitable for
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- * debugging. The exact presentation format is unspecified and may vary
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- * between implementations and versions.
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- *
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- * @implSpec If a value is present the result must include its string
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- * representation in the result. Empty and present Optionals must be
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- * unambiguously differentiable.
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- *
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- * @return the string representation of this instance
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- */
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- @Override
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- public String toString() {
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- return value != null
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- ? String.format("Optional[%s]", value)
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- : "Optional.empty";
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- }
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-}
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Andy Scherzinger