java 容器性能效率比较

java Array和ArrayList比较

源码:

@Test
    public void TestArrayAndList( ){
        long nowStart;
        long nowStop;
        Integer fillData = 1;
        Integer [] arrayInt = new Integer[100_000_000];
        ArrayList<Integer> arrayList = new ArrayList<Integer>( 100_000_000);
        int indx = 0;

        for (indx = 0;indx< 100_000_000 ;++indx){
            arrayList.add(fillData);
        }
        for (indx = 0;indx< 100_000_000 ;++indx){
            arrayInt[indx]=(fillData);
        }

        System.out.println("Start array...");
        nowStart = System.currentTimeMillis();
        for (indx = 0;indx< arrayInt.length ;++indx){
            fillData=arrayInt[indx];
        }
        nowStop = System.currentTimeMillis();
        System.out.println("array Time:"+(nowStop - nowStart)+"mS"); //array Time:3mS

        System.out.println("Start arrayList...");
        nowStart = System.currentTimeMillis();
        for (indx = 0;indx< arrayList.size() ;++indx){
            fillData=arrayList.get(indx);
        }
        nowStop = System.currentTimeMillis();
        System.out.println("arrayList Time:"+(nowStop - nowStart)+"mS");//arrayList Time:79mS


    }

输出内容:

Start array...
array Time:3mS
Start arrayList...
arrayList Time:79mS