RandomAccess接口

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);

    }

}