如何在Google HTTP Client中增加ReadTimeout

时间:2017-05-03 09:41:12

标签: java google-app-engine google-authentication google-http-client

我的应用程序在GAE中运行。此应用程序使REST调用我的CloudML。

以下是

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();  

上述代码通常导致ReadTimeout异常。

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 

我们似乎可以添加HttpRequestInitializer自定义超时,但我们需要在创建HttpRequestFactory时传递GoogleCredential HttpRequestFactory requestFactory = httpTransport.createRequestFactory(GoogleCredential);

因此我无法使用自定义HTTPRequestInitializer。如何增加使用GoogleCredential HTTPRequestInitializer创建的HttpRequestFactory的readTimeout?

1 个答案:

答案 0 :(得分:4)

我还没有尝试过,但我希望您能够将请求初始化程序有效地链接在一起:

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,凭证可以设置标题等,然后您也可以设置读取超时。