数组越界

public class TestArrayCopy1
{
        public static void main(String[] args)
        {
                int ia [] = new int[]{1, 2, 3, 4, 5};
                int ib [] = new int[]{9, 8, 7, 6, 5, 4, 3};
                System.arraycopy(ia, 0, ib, ib.length-ia.length, ia.length);
                //复制源数组中从下标0开始的ia.length个元素到目的数组，从下标ib.length-ia.length的位置开始存储
                for(int i=0; i<ia.length; i++)
                {
                        System.out.print(ia[i]);
                }
                System.out.println();
                for(int i=0; i<ib.length; i++)
                {
                        System.out.print(ib[i]);
                }
                System.out.println();
        }
}
~

java.lang.ArrayIndexOutOfBoundsException