Compare the performance of traversing LinkedList and ArrayList

List traversing benchmark.java

package benchmark;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;

import java.util.*;

/**
 * Run with:
 * <code>
 * mvn clean install
 * java -jar target/benchmarks.jar ListsBenchmark -wi 10 -i 10  -f 1
 * </code>
 * @author David Soroko
 */

@State(Scope.Thread)
public class ListsBenchmark {
    int N = 1000;

    String[] array;
    LinkedList<String> linkedList;
    ArrayList<String> arrayList;

    @Setup(Level.Trial)
    public void setUp() {
        array = new String[N];
        linkedList = new LinkedList<>();
        arrayList = new ArrayList<>();

        for (int i = 0; i < N; i++) {
            String uuid = UUID.randomUUID().toString();
            linkedList.add(uuid);
            arrayList.add(uuid);
        }
    }

    @Benchmark
    public void forArray(Blackhole bh) {
        for (int i = 0; i < N; i++) {
            bh.consume(array[i]);
        }
    }

    @Benchmark
    public void iteratorLinkedList(Blackhole bh) {
        iterate(linkedList, bh);
    }

    @Benchmark
    public void iteratorArrayList(Blackhole bh) {
        iterate(arrayList, bh);
    }

    @Benchmark
    public void forLinkedList(Blackhole bh) {
        iterateFor(linkedList, bh);
    }

    @Benchmark
    public void forArrayList(Blackhole bh) {
        iterateFor(arrayList, bh);
    }

    private void iterateFor(List list, Blackhole bh) {
        for (int i = 0; i < N; i++) {
            bh.consume(list.get(i));
        }
    }

    private void iterate(List list, Blackhole bh) {
        Iterator<String> iter = list.iterator();
        while (iter.hasNext()) {
            bh.consume(iter.next());
        }
    }
}