IOException: “Received authentication challenge is null” (Apache Harmony/Android)

问题

I am trying to send a GET via Android's HttpURLConnection (imported from org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnection), and upon receiving the response, an IOException is thrown:

in doRequestInternal(): "Received authentication challenge is null"

What does this error mean, and what is causing this? I am writing OAuth parameters to the Authorization header, but I do this on other occasions, too, without problems.

    if (connection == null) {
        connection = (HttpURLConnection) new URL(endpointUrl).openConnection();
        connection.setRequestMethod("GET");
    }

    //... do some OAuth message signing

    connection.connect();

    int statusCode = connection.getResponseCode(); // throws IOException

回答1:

I found out the reason.

First of all, to all who aren't aware of what this error means (I sure wasn't): This exception is thrown if the server replies with a 401. Very intuitive, considering that it was thrown in getResponseCode() (i.o.w. you are never able to check for 401s yourself, but have to catch this IOException instead...).

The actual cause for the 401 was that I didn't send an OAuth verifier code where it was expected at this point.

回答2:

Maybe will be useful for somebody...

This exception just means malformed answer headers: the "WWW-Authenticate" header was not found. Also, chunked answers with 401 code are not supported, so you'll need "Content-Length" header (can be zero).

回答3:

Just add this header to the request (in server side):

WWW-Authenticate: None

回答4:

Please note that there are two authentication approaches: HTTP Authentication and token-based authentication. If you are using HTTP Authentication then you have to follow referenced specification: include WWW-Authenticate header field on server side, use java.net.Authenticator locally, etc. If you are using token-based authentication then obviously you have to use cookies to store the token and make able to keep long lived sessions alive. In such case put the next code into android.app.Application.onCreate()

CookieManager cookieManager = new CookieManager();
CookieHandler.setDefault(cookieManager);

and you won't have troubles when receiving HTTP 401 from the server without WWW-Authenticate header field.

来源：https://stackoverflow.com/questions/1357372/ioexception-received-authentication-challenge-is-null-apache-harmony-android

标签

java

android

httpurlconnection