### API * public static Object newInstance\(Class&lt;?&gt; componentType, int length\)获取一个数组 ``` int[] num = (int[]) Array.newInstance(int.class, 10); ``` * 获取泛型数组 ``` private <T> T[] toArray(Class<T> cls, int length){ return (T[]) Array.newInstance(cls.getComponentType(), length); } ```