io.yupiik.batch.runtime.iterator.FlatMappingIterator Maven / Gradle / Ivy
/*
* Copyright (c) 2021-2022 - Yupiik SAS - https://www.yupiik.com
* 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 io.yupiik.batch.runtime.iterator;
import java.util.Iterator;
import java.util.function.Function;
public class FlatMappingIterator implements Iterator, AutoCloseable {
private final Iterator delegate;
private final Function> function;
private Iterator current;
public FlatMappingIterator(final Iterator delegate, final Function> function) {
this.delegate = delegate;
this.function = function;
}
@Override
public boolean hasNext() {
while (current == null || !current.hasNext()) {
if (!delegate.hasNext()) {
return false;
}
current = function.apply(delegate.next());
}
return true;
}
@Override
public B next() {
return current.next();
}
@Override
public void close() throws Exception {
if (AutoCloseable.class.isInstance(delegate)) {
AutoCloseable.class.cast(delegate).close();
}
}
}