ClosingStream.java
/*
* Copyright 2021 Red Hat, Inc. and/or its affiliates
* and other contributors as indicated by the @author tags.
*
* 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
*
* http://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.keycloak.utils;
import java.util.Comparator;
import java.util.Iterator;
import java.util.Optional;
import java.util.Spliterator;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.BinaryOperator;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.IntFunction;
import java.util.function.Predicate;
import java.util.function.Supplier;
import java.util.function.ToDoubleFunction;
import java.util.function.ToIntFunction;
import java.util.function.ToLongFunction;
import java.util.stream.Collector;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.stream.Stream;
/**
* This stream will automatically close itself after terminal operation.
*/
class ClosingStream<R> implements Stream<R> {
private final Stream<R> delegate;
public ClosingStream(Stream<R> delegate) {
this.delegate = delegate;
}
@Override
public Stream<R> filter(Predicate<? super R> predicate) {
return new ClosingStream<>(delegate.filter(predicate));
}
@Override
public <R1> Stream<R1> map(Function<? super R, ? extends R1> mapper) {
return new ClosingStream<>(delegate.map(mapper));
}
@Override
public IntStream mapToInt(ToIntFunction<? super R> mapper) {
return new ClosingIntStream(delegate.mapToInt(mapper));
}
@Override
public LongStream mapToLong(ToLongFunction<? super R> mapper) {
return new ClosingLongStream(delegate.mapToLong(mapper));
}
@Override
public DoubleStream mapToDouble(ToDoubleFunction<? super R> mapper) {
return new ClosingDoubleStream(delegate.mapToDouble(mapper));
}
@Override
public <R1> Stream<R1> flatMap(Function<? super R, ? extends Stream<? extends R1>> mapper) {
return new ClosingStream<>(delegate.flatMap(mapper));
}
@Override
public IntStream flatMapToInt(Function<? super R, ? extends IntStream> mapper) {
return new ClosingIntStream(delegate.flatMapToInt(mapper));
}
@Override
public LongStream flatMapToLong(Function<? super R, ? extends LongStream> mapper) {
return new ClosingLongStream(delegate.flatMapToLong(mapper));
}
@Override
public DoubleStream flatMapToDouble(Function<? super R, ? extends DoubleStream> mapper) {
return new ClosingDoubleStream(delegate.flatMapToDouble(mapper));
}
@Override
public Stream<R> distinct() {
return new ClosingStream<>(delegate.distinct());
}
@Override
public Stream<R> sorted() {
return new ClosingStream<>(delegate.sorted());
}
@Override
public Stream<R> sorted(Comparator<? super R> comparator) {
return new ClosingStream<>(delegate.sorted(comparator));
}
@Override
public Stream<R> peek(Consumer<? super R> action) {
return new ClosingStream<>(delegate.peek(action));
}
@Override
public Stream<R> limit(long maxSize) {
return new ClosingStream<>(delegate.limit(maxSize));
}
@Override
public Stream<R> skip(long n) {
return new ClosingStream<>(delegate.skip(n));
}
@Override
public void forEach(Consumer<? super R> action) {
delegate.forEach(action);
close();
}
@Override
public void forEachOrdered(Consumer<? super R> action) {
delegate.forEachOrdered(action);
close();
}
@Override
public Object[] toArray() {
Object[] result = delegate.toArray();
close();
return result;
}
@Override
public <A> A[] toArray(IntFunction<A[]> generator) {
A[] result = delegate.toArray(generator);
close();
return result;
}
@Override
public R reduce(R identity, BinaryOperator<R> accumulator) {
R result = delegate.reduce(identity, accumulator);
close();
return result;
}
@Override
public Optional<R> reduce(BinaryOperator<R> accumulator) {
Optional<R> result = delegate.reduce(accumulator);
close();
return result;
}
@Override
public <U> U reduce(U identity, BiFunction<U, ? super R, U> accumulator, BinaryOperator<U> combiner) {
U result = delegate.reduce(identity, accumulator, combiner);
close();
return result;
}
@Override
public <R1> R1 collect(Supplier<R1> supplier, BiConsumer<R1, ? super R> accumulator, BiConsumer<R1, R1> combiner) {
R1 result = delegate.collect(supplier, accumulator, combiner);
close();
return result;
}
@Override
public <R1, A> R1 collect(Collector<? super R, A, R1> collector) {
R1 result = delegate.collect(collector);
close();
return result;
}
@Override
public Optional<R> min(Comparator<? super R> comparator) {
Optional<R> result = delegate.min(comparator);
close();
return result;
}
@Override
public Optional<R> max(Comparator<? super R> comparator) {
Optional<R> result = delegate.max(comparator);
close();
return result;
}
@Override
public long count() {
long result = delegate.count();
close();
return result;
}
@Override
public boolean anyMatch(Predicate<? super R> predicate) {
boolean result = delegate.anyMatch(predicate);
close();
return result;
}
@Override
public boolean allMatch(Predicate<? super R> predicate) {
boolean result = delegate.allMatch(predicate);
close();
return result;
}
@Override
public boolean noneMatch(Predicate<? super R> predicate) {
boolean result = delegate.noneMatch(predicate);
close();
return result;
}
@Override
public Optional<R> findFirst() {
Optional<R> result = delegate.findFirst();
close();
return result;
}
@Override
public Optional<R> findAny() {
Optional<R> result = delegate.findAny();
close();
return result;
}
@Override
public Iterator<R> iterator() {
return new ClosingIterator(delegate.iterator());
}
@Override
public Spliterator<R> spliterator() {
return new ClosingSpliterator(delegate.spliterator());
}
@Override
public boolean isParallel() {
return delegate.isParallel();
}
@Override
public Stream<R> sequential() {
return new ClosingStream<>(delegate.sequential());
}
@Override
public Stream<R> parallel() {
return new ClosingStream<>(delegate.parallel());
}
@Override
public Stream<R> unordered() {
return new ClosingStream<>(delegate.unordered());
}
@Override
public Stream<R> onClose(Runnable closeHandler) {
return new ClosingStream<>(delegate.onClose(closeHandler));
}
@Override
public void close() {
delegate.close();
}
private class ClosingIterator implements Iterator<R> {
private final Iterator<R> iterator;
public ClosingIterator(Iterator<R> iterator) {
this.iterator = iterator;
}
@Override
public boolean hasNext() {
final boolean res = iterator.hasNext();
if (! res) {
close();
}
return res;
}
@Override
public R next() {
return iterator.next();
}
@Override
public void remove() {
iterator.remove();
}
@Override
public void forEachRemaining(Consumer<? super R> action) {
iterator.forEachRemaining(action);
close();
}
}
private class ClosingSpliterator implements Spliterator<R> {
private final Spliterator<R> spliterator;
public ClosingSpliterator(Spliterator<R> spliterator) {
this.spliterator = spliterator;
}
@Override
public boolean tryAdvance(Consumer<? super R> action) {
final boolean res = spliterator.tryAdvance(action);
if (! res) {
close();
}
return res;
}
@Override
public void forEachRemaining(Consumer<? super R> action) {
spliterator.forEachRemaining(action);
close();
}
@Override
public Spliterator<R> trySplit() {
return spliterator.trySplit();
}
@Override
public long estimateSize() {
return spliterator.estimateSize();
}
@Override
public long getExactSizeIfKnown() {
return spliterator.getExactSizeIfKnown();
}
@Override
public int characteristics() {
return spliterator.characteristics();
}
@Override
public boolean hasCharacteristics(int characteristics) {
return spliterator.hasCharacteristics(characteristics);
}
@Override
public Comparator<? super R> getComparator() {
return spliterator.getComparator();
}
}
}