如何在 Google HTTP 客户端中增加 ReadTimeout

Posted 2023-03-10

【中文标题】如何在 Google HTTP 客户端中增加 ReadTimeout

【英文标题】：How to increase ReadTimeout in Google HTTP Client

【发布时间】：2017-10-01 01:45:33

【问题描述】：

我的应用程序在 GAE 中运行。此应用程序对我的 CloudML 进行 REST 调用。

这是代码

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();  

上面的代码经常会导致 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 

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 时传递 GoogleCredential HttpRequestFactory requestFactory = httpTransport.createRequestFactory(GoogleCredential);

因此我不能使用自定义 HTTPRequestInitializer。如何增加使用 GoogleCredential HTTPRequestInitializer 创建的 HttpRequestFactory 的 readTimeout？

【参考方案1】：

我还没有尝试过，但我希望您能够有效地将请求初始化程序链接在一起：

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，当一个新请求被创建时，凭证可以设置标题等，然后你也可以设置读取超时。

【讨论】：

我使用了下面的 lamda 相当于上面的HttpRequestInitializer requestInitializer = request -> credential.initialize(request); request.setReadTimeout(0);; HttpRequestFactory requestFactory = httpTransport.createRequestFactory(requestInitializer);

@sag：当然 - 会在我的回答中添加它作为替代方案。