Java 返回 ResponseEntity<List> 返回的 List<myObj>
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Return the List<myObj> returned by ResponseEntity<List>
提问by ND_27
My REST client uses RestTemplate to obtain a List of objects.
我的 REST 客户端使用 RestTemplate 来获取对象列表。
ResponseEntitiy<List> res = restTemplate.postForEntity(getUrl(), myDTO, List.class);
Now I want to use the list returned and return it as List to the calling class. In case of string, toString could be used, but what is the work around for lists?
现在我想使用返回的列表并将其作为 List 返回给调用类。在字符串的情况下，可以使用 toString，但是列表的解决方法是什么？
采纳答案by Christophe L
First off, if you know the type of elements in your List, you may want to use the ParameterizedTypeReferenceclass like so.
首先，如果您知道 List 中元素的类型，您可能希望ParameterizedTypeReference像这样使用该类。
ResponseEntity<List<MyObj>> res = restTemplate.postForEntity(getUrl(), myDTO, new ParameterizedTypeReference<List<MyObj>>() {});
Then if you just want to return the list you can do:
然后，如果您只想返回列表，您可以执行以下操作：
return res.getBody();
And if all you care about is the list, you can just do:
如果你只关心列表，你可以这样做：
// postForEntity returns a ResponseEntity, postForObject returns the body directly.
return restTemplate.postForObject(getUrl(), myDTO, new ParameterizedTypeReference<List<MyObj>>() {});
回答by kaybee99
I couldn't get the accepted answer to work. It seems postForEntityno longer has this method signature. I had to use restTemplate.exchange()instead:
我无法得到公认的工作答案。似乎postForEntity不再有这个方法签名。我不得不restTemplate.exchange()改用：
ResponseEntity<List<MyObj>> res = restTemplate.exchange(getUrl(), HttpMethod.POST, myDTO, new ParameterizedTypeReference<List<MyObj>>() {});
Then to return the list, as above:
然后返回列表，如上：
return res.getBody();
回答by RikudouSennin
In the latest version (Spring Framework 5.1.6) both the answers are not working.
As kaybee99 mentioned in his answerpostForEntitymethod signature got changed.
Also the restTemplate.exchange()method and its overloads need a RequestEntity<T>or its parent HttpEntity<T>object. Unable to pass my DTO object as mentioned.
在最新版本（Spring Framework 5.1.6）中，这两个答案都不起作用。正如 kaybee99 在他的回答postForEntity方法中提到的那样签名被改变了。此外，该restTemplate.exchange()方法及其重载需要 aRequestEntity<T>或其父HttpEntity<T>对象。如上所述无法传递我的 DTO 对象。
Here is the code which worked for me
这是对我有用的代码
List<Shinobi> shinobis = new ArrayList<>();
shinobis.add(new Shinobi(1, "Naruto", "Uzumaki"));
shinobis.add(new Shinobi(2, "Sasuke", "Uchiha");
RequestEntity<List<Shinobi>> request = RequestEntity
.post(new URI(getUrl()))
.accept(MediaType.APPLICATION_JSON)
.contentType(MediaType.APPLICATION_JSON)
.body(shinobis);
ResponseEntity<List<Shinobi>> response = restTemplate.exchange(
getUrl(),
HttpMethod.POST,
request,
new ParameterizedTypeReference<List<Shinobi>>() {}
);
List<Shinobi> result = response.getBody();
Hope it helps someone.
希望它可以帮助某人。
回答by kris
You have unwrap the ResponseEntity and you can get the object(list)
你已经解开 ResponseEntity 并且你可以得到对象（列表）
res.getBody()
回答by kris
You can use the ParameterizedTypeReferenceclass of Spring to convert to List the data returned by ResponseEntity
可以使用Spring的ParameterizedTypeReference类将ResponseEntity返回的数据转换为List
ResponseEntity<List<MyObject>> resp = restTemplate.exchange(url, HttpMethod.GET, null, new ParameterizedTypeReference<List<MyObject>>(){});
if(resp != null && resp.hasBody()){
List<MyObject> myList = resp.getBody();
}
