package com.lion;import java.util.ArrayList;import java.util.Date;import java.util.Iterator;import java.util.LinkedList;import java.util.List;import java.util.RandomAccess;public class RandomAccessTest {    public static void traverse(List list) {        long startTime;        long endTime;        //遍历前先判读是否实现了RandomAccess接口        if (list instanceof RandomAccess) {           System.out.println(list.getClass()+"实现了RandomAccess接口");        }        else        {             System.out.println(list.getClass()+"未实现RandomAccess接口");        }                System.out.println("\n以实现RandomAccess接口方式访问");        startTime = System.currentTimeMillis();        for (int i = 0; i < list.size(); i++) {            Object o = list.get(i);            // System.out.println(o);        }        endTime = System.currentTimeMillis();        System.out.println("耗时：" + (endTime - startTime));                System.out.println("\n以未实现RandomAccess接口方式访问");        startTime = System.currentTimeMillis();        for (Iterator iter = list.iterator(); iter.hasNext();) {            Object o = iter.next();            // System.out.println(o);        }        endTime = System.currentTimeMillis();        System.out.println("耗时：" + (endTime - startTime));    }    /**     * @param args     */    public static void main(String[] args) {        List arraylist = new ArrayList();        // 添加1000个元素        for (int i = 0; i < 100000; i++) {            arraylist.add("aaa");        }        List linkList = new LinkedList();        // 添加1000个元素        for (int i = 0; i < 100000; i++) {            linkList.add("aaa");        }        traverse(arraylist);        traverse(linkList);    }}