LinkedList与ArrayList的性能比较

package jiben.data;

import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;

public class Listsd {

public static void main(String[] args) {
// TODO Auto-generated method stub

//添加记录是
int sum = 10000000;
//移除记录数
int rm = 300;
//修改记录数
int cha = 30000;

System.out.println("start add "+sum/10000+"W rows;  rm "+300+" rows;cha "+cha+" rows");
System.out.println("--------------------------------------");
System.out.println("");
System.out.println("");
long  n = System.nanoTime();
List<String> al = new ArrayList<String>();
Listsd.test(al,sum,rm,cha,n);

n = System.nanoTime();
al = new LinkedList<String>();
Listsd.test(al,sum,rm,cha,n);

}

public static void test(List<String> al,int sum,int rm,int cha,long  n){
if(al instanceof ArrayList)
System.out.println("ArrayList");
else
System.out.println("LinkedList");
System.out.println("init time(ns) "+(System.nanoTime()-n));

long s = System.currentTimeMillis();
for(int i=0;i<sum;i++){
al.add("hello");
}
System.out.println("add time "+(System.currentTimeMillis()-s));

s = System.currentTimeMillis();
ListIterator<String> it = al.listIterator();
while(it.hasNext()){
it.next();
}
System.out.println("read time "+(System.currentTimeMillis()-s));

s = System.currentTimeMillis();
for(int i=0;i<cha;i++)
al.set(i, "word");
System.out.println("change rows time "+(System.currentTimeMillis()-s));

s = System.currentTimeMillis();
for(int i=0;i<rm;i++)
al.remove(i);
System.out.println("remove rows time "+(System.currentTimeMillis()-s));

s = System.currentTimeMillis();
al.clear();
System.out.println("clear time "+(System.currentTimeMillis()-s));

System.out.println("--------------------------------------");
System.out.println("");
System.out.println("");
}

}

console结果：

start add 1000W rows;  rm 300 rows;cha 30000 rows

--------------------------------------

ArrayList

init time(ns) 39822

add time 160

read time 11

change rows time 3

remove rows time 3163

clear time 12

--------------------------------------

LinkedList

init time(ns) 756210

add time 2831

read time 79

change rows time 644

remove rows time 0

clear time 66

--------------------------------------

结论选择List的时候
1.如果集合特别长没有删除元素的操作，首选ArrayList.否则选择LinkedList.ArrayList删除元素耗费时间远大于LinkedList.

2.集合不是很大，选择ArrayList(init、add、read的时间很短)