性能比较

package jjj;

import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedList;

public class ArrayListVSLinkedList{
     public static void ArrayListTest(long num){
         ArrayList list = new ArrayList()  ;
         long berforeTime= new Date().getTime();
         for(int i=0;i<num;i++){ //在数组的头部插入一个元素
             list.add(0,i);
         }
         long afterTime = new Date().getTime();
         System.err.println("The process ArrayListTest used a total time is "+(afterTime-berforeTime) +" millisecondes !" );
     }
    public static void linkedList(long num){
         LinkedList  list = new LinkedList();
         long berforeTime= new Date().getTime();
         for(int i=0;i<num;i++) {
             list.add(0,i); /*添加元素：添加单个元素 
 如果不指定索引的话，元素将被添加到链表的最后*/
         }
         long afterTime = new Date().getTime();
         System.err.println("The process linkedList used a total time is "+(afterTime-berforeTime) +" millisecondes !" );
    }
    public static void main(String[] args){
        ArrayListVSLinkedList.ArrayListTest(999999);
        ArrayListVSLinkedList.linkedList(999999);
    }
}