restTemplate.getForObject（“URL”，Object [] .class）可以返回NULL吗？

Question

I have used the solution from this answer: Get list of JSON objects with Spring RestTemplate It works perfectly. 我使用了这个答案的解决方案：使用Spring RestTemplate获取JSON对象列表它完美地运行。 It doing exactly what I need. 它完全符合我的需要。

ProcessDefinition[] response = restTemplate.getForObject(url, ProcessDefinition[].class);

Is it enought: 是否应该：

return Arrays.asList(response);

or will be better this way: 或者这样会更好：

return Arrays.asList(Optional.ofNullable(response).orElse(new ProcessDefinition[0]));

PS Sorry for starting the new topic, but my karma does not allow me to comment the answer. PS很抱歉开始新主题，但我的业力不允许我评论答案。

Answer 1

Yes, the result of 是的，结果

ProcessDefinition[] response = restTemplate.getForObject(url, ProcessDefinition[].class);

can be null if HTTP response was empty (not [] , but totally empty). 如果HTTP响应为空（不是[] ，但是完全为空），则可以为null 。

So it is safer to check it if you are not sure that HTTP response never be empty. 因此，如果您不确定HTTP响应永远不会为空，那么检查它会更安全。

return Optional.ofNullable(response).map(Arrays::asList).orElseGet(ArrayList::new)

or 要么

return Optional.ofNullable(response).map(Stream::of).orElseGet(Stream::empty)

if you need a stream. 如果你需要一个流。