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我的服务中有以下问题我正在构建对象 X 但是为了构建它我需要进行一些 http 调用以获取所有必需的数据来填充它（每个其余部分都填充对象的某些部分。）为了保持性能高我认为使调用异步并且在所有调用完成后将对象返回给调用者会很好。它看起来像这样

ListenableFuture<ResponseEntity<String>> future1 = asycTemp.exchange(url, method, requestEntity, responseType);
future1.addCallback({
    //process response and set fields
    complexObject.field1 = "PARSERD RESPONSE"
},{
    //in case of fail fill default or take some ather actions
})

我不知道如何等待所有功能完成。我想它们是解决此类问题的一些标准弹簧方式。在此先感谢您的任何建议。春季版 - 4.2.4.RELEASE 最好的问候

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1 回答 1

2

改编自Waiting for callback for multiple futures。

此示例仅请求 Google 和 Microsoft 主页。当在回调中收到响应并且我完成了处理时，我减少了CountDownLatch。我等待 CountDownLatch，“阻塞”当前线程，直到 CountDownLatch 达到 0。

如果您的调用失败或成功，请务必减少，因为您必须点击 0 才能继续该方法！

public static void main(String[] args) throws Exception {
    String googleUrl = "http://www.google.com";
    String microsoftUrl = "http://www.microsoft.com";
    AsyncRestTemplate asyncRestTemplate = new AsyncRestTemplate();
    ListenableFuture<ResponseEntity<String>> googleFuture = asyncRestTemplate.exchange(googleUrl, HttpMethod.GET, null, String.class);
    ListenableFuture<ResponseEntity<String>> microsoftFuture = asyncRestTemplate.exchange(microsoftUrl, HttpMethod.GET, null, String.class);
    final CountDownLatch countDownLatch = new CountDownLatch(2);
    ListenableFutureCallback<ResponseEntity<java.lang.String>> listenableFutureCallback = new ListenableFutureCallback<ResponseEntity<String>>() {

        public void onSuccess(ResponseEntity<String> stringResponseEntity) {
            System.out.println(String.format("[Thread %d] Status Code: %d. Body size: %d",
                    Thread.currentThread().getId(),
                    stringResponseEntity.getStatusCode().value(),
                    stringResponseEntity.getBody().length()
            ));
            countDownLatch.countDown();
        }

        public void onFailure(Throwable throwable) {
            System.err.println(throwable.getMessage());
            countDownLatch.countDown();
        }
    };
    googleFuture.addCallback(listenableFutureCallback);
    microsoftFuture.addCallback(listenableFutureCallback);
    System.out.println(String.format("[Thread %d] This line executed immediately.", Thread.currentThread().getId()));
    countDownLatch.await();
    System.out.println(String.format("[Thread %d] All responses received.", Thread.currentThread().getId()));

}

我的控制台的输出：

[Thread 1] This line executed immediately.
[Thread 14] Status Code: 200. Body size: 112654
[Thread 13] Status Code: 200. Body size: 19087
[Thread 1] All responses received.
于 2016-02-05T20:46:18.747 回答