org.infinispan.commons.util.IteratorMapper Maven / Gradle / Ivy
package org.infinispan.commons.util;
import java.util.Iterator;
import java.util.function.Function;
/**
* A iterator that maps each value to the output of the Function. Note that the remove is supported if the iterator
* originally supported remove. This iterator implements {@link CloseableIterator} and will close the provided iterator
* if it also implemented CloseableIterator.
* @author William Burns
* @since 8.0
*/
public class IteratorMapper implements CloseableIterator {
private final Iterator iterator;
private final Function function;
public IteratorMapper(Iterator iterator, Function function) {
if (iterator == null || function == null) {
throw new NullPointerException();
}
this.iterator = iterator;
this.function = function;
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public S next() {
E value = iterator.next();
return function.apply(value);
}
@Override
public void remove() {
iterator.remove();
}
@Override
public void close() {
if (iterator instanceof CloseableIterator) {
((CloseableIterator) iterator).close();
}
}
}