Java – Convert Iterator to List

iteratorjavalist

Given Iterator<Element>, how can we conveniently convert that Iterator to a List<Element>, so that we can use List's operations on it such as get(index), add(element), etc.

Best Answer

Better use a library like Guava:

import com.google.common.collect.Lists;

Iterator<Element> myIterator = ... //some iterator
List<Element> myList = Lists.newArrayList(myIterator);

Another Guava example:

ImmutableList.copyOf(myIterator);

or Apache Commons Collections:

import org.apache.commons.collections.IteratorUtils;

Iterator<Element> myIterator = ...//some iterator

List<Element> myList = IteratorUtils.toList(myIterator);
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