java list三种遍历方法性能比較

package com.hisense.tiger.list;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class ListTest {
	public static void main(String[] args)
	{
		List<String> list = new ArrayList<String>();
		long t1,t2;
		for(int j = 0; j < 10000000; j++)
		{
			list.add("aaaaaa" + j);
		}
		System.out.println("List first visit method:");
		t1=System.currentTimeMillis();
		for(String tmp:list)
		{
			//System.out.println(tmp);
		}
		t2=System.currentTimeMillis();
		System.out.println("Run Time:" + (t2 -t1) + "(ms)");
		System.out.println("List second visit method:");
		
		t1=System.currentTimeMillis();
		for(int i = 0; i < list.size(); i++)
		{
			list.get(i);
			//System.out.println(list.get(i));
		}
		t2=System.currentTimeMillis();
		System.out.println("Run Time:" + (t2 -t1) + "(ms)");
		
		System.out.println("List Third visit method:");
		Iterator<String> iter = list.iterator();
		
		t1=System.currentTimeMillis();
		while(iter.hasNext())
		{
			iter.next();
			//System.out.println(iter.next());
		}
		t2=System.currentTimeMillis();
		System.out.println("Run Time:" + (t2 -t1) + "(ms)");
				
		System.out.println("Finished!!!!!!!!");
		
		
	}
}