如何增加Google HTTP客户端中的ReadTimeout

Question

我的应用程序在GAE中运行。此应用程序将休息呼叫我的CloudMl。

这是该

的代码

GoogleCredential credential = GoogleCredential.getApplicationDefault()
        .createScoped(Collections.singleton(CLOUDML_SCOPE));
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
HttpRequestFactory requestFactory = httpTransport.createRequestFactory(
        credential);
GenericUrl url = new GenericUrl(cloudMLRestUrl);
JacksonFactory jacksonFactory = new JacksonFactory();
JsonHttpContent jsonHttpContent = new JsonHttpContent(jacksonFactory, getPayLoad());
ByteArrayOutputStream baos = new ByteArrayOutputStream();
jsonHttpContent.setWrapperKey("instances");
jsonHttpContent.writeTo(baos);
LOG.info("Executing request... " + baos.toString());
HttpRequest request = requestFactory.buildPostRequest(url, jsonHttpContent);
HttpResponse response = request.execute();  

通常会导致ReadTimeout异常导致上述代码。

java.net.SocketTimeoutException: Read timed out at 
java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_121] at 
java.net.SocketInputStream.socketRead(SocketInputStream.java:116) 
~[na:1.8.0_121] at 
java.net.SocketInputStream.read(SocketInputStream.java:171) ~[na:1.8.0_121] 
at 

似乎我们可以使用自定义超时添加httprequestinitializer，但是我们需要在创建httprequestfactory时通过googlecredential HttpRequestFactory requestFactory = httpTransport.createRequestFactory(GoogleCredential);

因此，我不能使用自定义的httprequestinitializer。如何增加使用Googlecredential httprequestinitializer创建的httprequestFactory的ReadTimeout？

Answer 1

我还没有尝试过，但是我希望您能够有效地将请求初始化器链接在一起：

final GoogleCredential credential = ...;
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
HttpRequestFactory requestFactory = httpTransport.createRequestFactory(
    new HttpRequestInitializer() {
        @Override public void initialize(HttpRequest request) {
            credential.initialize(request);
            request.setReadTimeout(...);
        }
    });

或作为lambda表达式：

final GoogleCredential credential = ...;
HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
HttpRequestFactory requestFactory = httpTransport.createRequestFactory(
    request -> {
        credential.initialize(request);
        request.setReadTimeout(...);
    });

换句话说，当创建新请求时，凭据能够设置标题等，然后还设置了读取超时。