java long[] 怎么转 Long[]

java 怎么实现 long[] 转 Long[]呢？不用循环。用java8 lamdba如何实现啊。
我当前有段代码

 String[] a = {"1","2","3","4"};
 long[] array = Arrays.stream(a).mapToLong(s -> Long.valueOf(s)).toArray();

但有个接口要Long[]型的参数。

 String[] a = {"1","2","3","4"};
Long[] arr = Stream.of(a).map(s -> Long.valueOf(s)).collect(Collectors.toList()).toArray(new Long[]{});

已经找到解决方法，不过楼上写的好像更容易懂。

 String[] a = {"1","2","3","4"};
 Long[] array = Arrays.stream(a).map(s -> Long.valueOf(s)).toArray(Long[]::new);