将list转换为数组的正确使用方法
List list = new ArrayList();
1.
Long[] l = new Long[<total size>];
list.toArray(l);
2.
Long[] l = (Long[]) list.toArray(new Long[0]);
3.
Long[] a = new Long[<total size>];
Long[] l = (Long[]) list.toArray(a);
3.
Long[] a = new Long[<total size>];
Long[] l = (Long[]) list.toArray(a);