How to debug http calls on Android devices?

Question

I'm writing a Lovefilm client for Android, and it's not going too badly except I keep having problems with the remote calls to retrieve data from the API.

Does anyone have any tips for debugging remote calls like this? Can I tcpdump on Android or is there a native way of doing it?

For example, I'm using the Scribe-java library for OAuth to access the Lovefilm API, I can authenticate find and retrieve a list of films on the users account fine when the device is running Gingerbread, but trying to retrieve the accessToken on Froyo causes a blank response & and apparent response code of -1, I'd like to be able to see what's going on under the cvers their.

Another example I'd like to be able to the raw http for is trying to run a search, I get and IOError that says "Received authentication challenge is null"

Answer 1

I've used Fiddler (http-proxy for debugging http calls) with the android emulator in these cases. Just start the proxy, and start the emulator with the correct proxy address (-http-proxy ).

Answer 2

Fiddler is the most useful option. On the emulator @Scythe answer will work, but on a real device you will need to set the proxy in the Apache Http Client. The following code will do that:

HttpHost proxy = new HttpHost("youripaddr", 8888); 
params.setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); 

If you are using https, fiddler is not so useful. In that case can enable the build in logging support in Apache Http Client. The following code does that:

Headers only:

java.util.logging.Logger apacheHeaderLog = java.util.logging.Logger.getLogger("org.apache.http.headers");       
apacheHeaderLog.setLevel(java.util.logging.Level.FINEST);

Headers & Wire:

java.util.logging.Logger apacheWireLog = java.util.logging.Logger.getLogger("org.apache.http.wire");
apacheWireLog.setLevel(java.util.logging.Level.FINEST);

Note that this will have to have a java.util.logging Handler configured at finest level and the default handler is configured to log to logcat, which will filter DEBUG (finest) entries by default.