方法
arraycopy
Copies an array from the specified source array, beginning at the specified position, to the specified position of the destination array.
从源数组中的指定位置开始 到 目标数组的指定位置开始,
public static native void arraycopy(Object src, int srcPos, Object dest, int destPos, int length);
src: the source array. 源数组
srcPos: starting position in the source array. 源数组的起始位置
dest: the destination array. 目标数组
destPos: starting position in the destination data. 目标数组的起始位置
length: the number of array elements to be copied. 被拷贝的数组元素数量