Test performance of Map implementations

MapPerformanceTest.java

package uk.co.validus.billingserver.util;

import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.commons.collections4.map.LinkedMap;

public class MapPerformanceTest
{
	public static final int MAP_SIZE = 1000000;

	public static void main(String[] args)
	{
		testPerformance("Collections.synchronizedMap backed by LinkedHashMap", Collections.synchronizedMap(new LinkedHashMap<Integer, String>()));
		testPerformance("Collections.synchronizedMap backed by LinkedMap", Collections.synchronizedMap(new LinkedMap<Integer, String>()));
		testPerformance("ConcurrentHashMap", new ConcurrentHashMap<Integer, String>());
		testPerformance("TreeMap", new TreeMap<Integer, String>());
	}

	public static void testPerformance(String testName, Map<Integer, String> testMap)
	{
		System.out.println("Starting test for " + testName + " performance");
		final long start = System.currentTimeMillis();

		for (int i = 0; i < MAP_SIZE; i++)
		{
			testMap.put(i, "Test item " + i);
		}
		System.out.println("\tTime to populate map: " + (System.currentTimeMillis() - start) + "ms");

		testMap.get(Double.valueOf(Math.floor(MAP_SIZE / 2)).intValue());
		System.out.println("\tTime to find midpoint value: " + (System.currentTimeMillis() - start) + "ms");

		final Iterator<Entry<Integer, String>> iter = testMap.entrySet().iterator();
		while (iter.hasNext())
		{
			iter.next();
		}
		System.out.println("\tTime to iterate map: " + (System.currentTimeMillis() - start) + "ms");

		System.out.println("\tTime to complete test: " + (System.currentTimeMillis() - start) + "ms");
	}
}