Return 来自异步 rest 模板的值 spring
Return Value from async rest template spring
我正在使用 spring
创建异步休息调用
@GetMapping(path = "/testingAsync")
public String value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
ListenableFuture<ResponseEntity<User>> futureEntity = restTemplate.getForEntity(baseUrl, User.class);
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<User>>() {
@Override
public void onSuccess(ResponseEntity<User> result) {
System.out.println(result.getBody().getName());
// instead of this how can i return the value to the user ?
}
@Override
public void onFailure(Throwable ex) {
}
});
return "DONE"; // instead of done i want to return value to the user comming from the rest call
}
有什么方法可以将 ListenableFuture 转换为使用 java 8 中使用的 CompletableFuture?
我不太了解 Spring 中的异步调用,但我想你可以 return 通过 ResponseBody
看起来像这样:
@GetMapping(path = "/testingAsync")
@ResponseBody
public String value() throws ExecutionException, InterruptedException, TimeoutException {
...
...
@Override
public void onSuccess(ResponseEntity<User> result) {
return result.getBody().getName();
}
...
}
抱歉,如果这不是您要问的问题。
您基本上可以做两件事。
- 删除
ListenableFutureCallback
并简单地 return ListenableFuture
- 创建一个
DeferredResult
并在 ListenableFutureCallback
中设置它的值。
返回 ListenableFuture
@GetMapping(path = "/testingAsync")
public ListenableFuture<ResponseEntity<User>> value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
return restTemplate.getForEntity(baseUrl, User.class);
}
Spring MVC 将添加一个 ListenableFutureCallback
本身来填充 DeferredResult
,最终您将得到一个 User
。
使用 DeferredResult
如果您想更好地控制要 return 的内容,您可以使用 DeferredResult
并自行设置值。
@GetMapping(path = "/testingAsync")
public DeferredResult<String> value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
final DeferredResult<String> result = new DeferredResult<>();
ListenableFuture<ResponseEntity<User>> futureEntity = restTemplate.getForEntity(baseUrl, User.class);
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<User>>() {
@Override
public void onSuccess(ResponseEntity<User> result) {
System.out.println(result.getBody().getName());
result.setResult(result.getBody().getName());
}
@Override
public void onFailure(Throwable ex) {
result.setErrorResult(ex.getMessage());
}
});
return result;
}
我正在使用 spring
创建异步休息调用@GetMapping(path = "/testingAsync")
public String value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
ListenableFuture<ResponseEntity<User>> futureEntity = restTemplate.getForEntity(baseUrl, User.class);
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<User>>() {
@Override
public void onSuccess(ResponseEntity<User> result) {
System.out.println(result.getBody().getName());
// instead of this how can i return the value to the user ?
}
@Override
public void onFailure(Throwable ex) {
}
});
return "DONE"; // instead of done i want to return value to the user comming from the rest call
}
有什么方法可以将 ListenableFuture 转换为使用 java 8 中使用的 CompletableFuture?
我不太了解 Spring 中的异步调用,但我想你可以 return 通过 ResponseBody
看起来像这样:
@GetMapping(path = "/testingAsync")
@ResponseBody
public String value() throws ExecutionException, InterruptedException, TimeoutException {
...
...
@Override
public void onSuccess(ResponseEntity<User> result) {
return result.getBody().getName();
}
...
}
抱歉,如果这不是您要问的问题。
您基本上可以做两件事。
- 删除
ListenableFutureCallback
并简单地 returnListenableFuture
- 创建一个
DeferredResult
并在ListenableFutureCallback
中设置它的值。
返回 ListenableFuture
@GetMapping(path = "/testingAsync")
public ListenableFuture<ResponseEntity<User>> value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
return restTemplate.getForEntity(baseUrl, User.class);
}
Spring MVC 将添加一个 ListenableFutureCallback
本身来填充 DeferredResult
,最终您将得到一个 User
。
使用 DeferredResult
如果您想更好地控制要 return 的内容,您可以使用 DeferredResult
并自行设置值。
@GetMapping(path = "/testingAsync")
public DeferredResult<String> value() throws ExecutionException, InterruptedException, TimeoutException {
AsyncRestTemplate restTemplate = new AsyncRestTemplate();
String baseUrl = "https://api.github.com/users/XXX";
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setAccept(Arrays.asList(MediaType.APPLICATION_JSON));
String value = "";
HttpEntity entity = new HttpEntity("parameters", requestHeaders);
final DeferredResult<String> result = new DeferredResult<>();
ListenableFuture<ResponseEntity<User>> futureEntity = restTemplate.getForEntity(baseUrl, User.class);
futureEntity.addCallback(new ListenableFutureCallback<ResponseEntity<User>>() {
@Override
public void onSuccess(ResponseEntity<User> result) {
System.out.println(result.getBody().getName());
result.setResult(result.getBody().getName());
}
@Override
public void onFailure(Throwable ex) {
result.setErrorResult(ex.getMessage());
}
});
return result;
}