java实现Array

public class MyArray {
    private int[] array;
    private int size;
    public MyArray(int capacity){
        this.array=new int[capacity];
        size=0;
    }
    public void insert(int element,int index)throws Exception{
        //判断访问下标是否超出范围
        if(index<0 || index>size){
            throw new IndexOutOfBoundsException("超出数组实际元素范围！");
        }
        //如果实际元素达到数组容量上限，则对数组进行扩容
        if(size>=array.length)
            resize();
        for (int i=size-1;i>=index;i--){
            array[i+1]=array[i];
        }
        array[index]=element;
        size++;
    }
    public void resize(){
        int[] arraynew=new int[array.length*2];
        //从旧数组复制到新数组
        System.arraycopy(array,0,arraynew,0,array.length);
        array=arraynew;
    }
    public void output(){
        for (int i=0;i<size;i++){
            System.out.println(array[i]);
        }
    }
    public int delete(int index)throws Exception{
        if(index<0 || index>=size)throw new IndexOutOfBoundsException("超出数组实际元素范围!");
        int deletedElement = array[index];
        for (int i=index;i<size-1;i++){
            array[i]=array[i+1];
        }
        size--;
        return deletedElement;
    }
}