Java语言list遍历的三种方法

Java语言list遍历的三种方法,代码如下：

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!!!!!!!!");  
          
          
    }  
}