net.markenwerk.commons.iterables.CombinedIterable Maven / Gradle / Ivy
/*
* Copyright (c) 2015, 2016 Torsten Krause, Markenwerk GmbH
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package net.markenwerk.commons.iterables;
import java.util.Iterator;
import net.markenwerk.commons.interfaces.Converter;
import net.markenwerk.commons.iterators.CombinedIterator;
import net.markenwerk.commons.iterators.ConvertingIterator;
/**
* An {@link CombinedIterable} is a {@link Iterable} that wraps arround some
* given {@link Iterable Iterables} and combines them into a single
* {@link Iterable} by iterating over all given {@link Iterable Iterables} in
* the order they were given.
*
*
* Calling {@link CombinedIterable#iterator()} creates an instance of
* {@link CombinedIterator}.
*
* @param
* The payload type.
* @author Torsten Krause (tk at markenwerk dot net)
* @since 1.0.0
*/
public final class CombinedIterable implements Iterable {
private final Iterable> iterables;
/**
* Creates a new {@link CombinedIterable} from the given sequence of
* {@link Iterable Iterables}.
*
* @param iterables
* The sequence of {@link Iterable Iterables} to combine into a
* single {@link Iterable}.
*
* @throws IllegalArgumentException
* If the given sequence of {@link Iterable Iterables} is
* {@literal null}.
*/
public CombinedIterable(Iterable... iterables) {
if (null == iterables) {
throw new IllegalArgumentException("iterables is null");
}
this.iterables = new ArrayIterable>(iterables);
}
/**
* Creates a new {@link CombinedIterable} from the given {@link Iterable} of
* {@link Iterable Iterables}.
*
* @param iterable
* The {@link Iterable} of {@link Iterable Iterables} to combine
* into a single {@link Iterable}.
*
* @throws IllegalArgumentException
* If the given {@link Iterable} of {@link Iterable Iterables}
* is {@literal null}.
*/
public CombinedIterable(Iterable> iterable) throws IllegalArgumentException {
if (null == iterable) {
throw new IllegalArgumentException("iterable is null");
}
this.iterables = iterable;
}
@Override
public CombinedIterator iterator() {
// @formatter:off
return new CombinedIterator(
new ConvertingIterator, Iterator>(
iterables.iterator(),
new Converter, Iterator>() {
@Override
public Iterator convert(Iterable iterable) {
return iterable.iterator();
}
}
)
);
// @formatter:on
}
}