来自Google App Engine的http请求 [英] http request from Google App Engine

问题描述

我尝试从我的Google App Engine webapp发出http请求，并发现我必须使用URLConnection，因为它是唯一的白名单类。对应的Clojure库是clojure.contrib.http.agent，我的代码如下：

 （defroutes example 
（GET/[]（http / string（http / http-agenthttp://www.example.com）））
（route / not-foundPage not found））
  

这在我的开发环境中正常工作 - 浏览器显示example.com的文本。但是当我用Google的开发应用服务器测试它：

  phrygian：example wei $ dev_appserver.sh war 
 2010 -09-28 14：53：36.120 java [43845：903] [Java CocoaComponent兼容模式]：启用
 ... 
 INFO：服务器运行在http：// localhost：8080 / 
  

当我加载页面时它刚刚挂起。没有错误，或任何东西。任何想法可能会发生什么？

解决方案

http-agent

从 API文档：

创建（并立即返回）代表在新线程中运行的HTTP
请求的代理。

http-connection ，它是HttpURLConnection的一个包装，因此应该工作。

另一种选择是尝试 clj-http 。 API似乎有点高级，但它使用可能被列入黑名单的 Apache HttpComponents 。 p>

我在猜测 http.async.client 是一个明确的no-go。

I'm trying to make http requests from my Google App Engine webapp, and discovered I have to use URLConnection since it's the only whitelisted class. The corresponding Clojure library is clojure.contrib.http.agent, and my code is as follows:

(defroutes example
  (GET "/" [] (http/string (http/http-agent "http://www.example.com")))
  (route/not-found "Page not found"))

This works fine in my development environment- the browser displays the text for example.com. But when I test it out with Google's development app server:

phrygian:example wei$ dev_appserver.sh war
2010-09-28 14:53:36.120 java[43845:903] [Java CocoaComponent compatibility mode]: Enabled
...
INFO: The server is running at http://localhost:8080/

It just hangs when I load the page. No error, or anything. Any idea what might be going on?

解决方案

http-agent creates threads so that might be why it does not work.

From the API documentation:

Creates (and immediately returns) an Agent representing an HTTP request running in a new thread.

You could try http-connection, which is a wrapper around HttpURLConnection, so this should work.

Another alternative is to try clj-http. The API seems to be a bit more high-level, but it uses Apache HttpComponents which might be blacklisted.

I am guessing http.async.client is a definite no-go due to its strong asynchronous approach.

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