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I'm trying to send https request using GAE technologies. But if I use 

HttpsURLConnection con = (HttpsURLConnection) obj.openConnection();

it will crash

java.lang.ClassCastException: com.google.apphosting.utils.security.urlfetch.URLFetchServiceStreamHandler$Connection cannot be cast to javax.net.ssl.HttpsURLConnection

If I change HttpsURLConnection to HttpURLConnection, everything will work ok, but I don't think https advantages will be used. So how can I send https request properly?

Tony
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  • Is it helpful for you? https://cloud.google.com/appengine/kb/general?hl=en#https and http://stackoverflow.com/questions/5367974/https-only-in-google-app-engine – Ravindra babu Aug 20 '15 at 10:43

2 Answers2

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I assume, that obj is of java.net.URL type. Simply, you should not use javax.net.ssl.HttpsURLConnection in this case.

URL#openConnection() method returns type java.net.URLConnection, and does not provide almost any guarantees on it subtypes (apart of weird javadoc description, see below*), and Google makes use of it. Your application should not rely on specifics of HttpsURLConnection. There are two options:

  • use only URLConnection - guaranteed by API,
  • use HttpURLConnection as URLFetchServiceStreamHandler$Connection extends it, and it is unlikely to be changed.

In both cases, HTTPS features will be used; casting does not change the nature of the object.

Other case are client certificates in GAE - see Client Authentication by Certificate in GAE java queston.

*Weird thing is, that javadoc for URL.openConnection says:

If for the URL's protocol (such as HTTP or JAR), there exists a public, specialized URLConnection subclass belonging to one of the following packages or one of their subpackages: java.lang, java.io, java.util, java.net, the connection returned will be of that subclass. For example, for HTTP an HttpURLConnection will be returned, and for JAR a JarURLConnection will be returned.

(source: https://docs.oracle.com/javase/8/docs/api/java/net/URL.html#openConnection)

HttpsConnction is not in any of mentioned packages, so Google is free to provide any type it wants to. But such description gives a possibility to add HttpsURLConnection in the future to - for example - java.util package, and then AppEngine implementation will be no longer relevant. This is only speculation, and most probably it will never happen - but there is no guarantee! :)

Community
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AreSo
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0

HttpURLConnection works for me

Surya Nair
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