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"
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 ).
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.
If your system can share the wi-fi connection you should be able to route packets from any device through your system and then using wireshark you can get monitor your calls or get a tcpdump.
Also , and more importantly , it would be best if you log your network calls and responses as suggested by #Matthew
Windows 7 wi-fi connection sharing : http://www.winsupersite.com/article/faqtip/windows-7-tip-of-the-week-use-wireless-hosted-networking-to-share-an-internet-connection-wirelessly.aspx
Since I always run into similar troubles and it seems a lot of people having the same issues over and over again I wrote up a quick tutorial for debugging client-server communication by using netcat and cURL.
That of course only works for the simplified case that you always 'fake' on side of the connection.
For eavesdropping you can use tools like tcpdump or Wireshark. Which will definitely be easier if you're able to run the server instance directly on your local machine.
Stetho is a great tool from FB which helps in debugging android Apps. You can have access to local data and have a check on your network using this.
http://facebook.github.io/stetho/
Related
I'm new to web-crawlers, trying to crawl ridership data of metro from the cellphone maps app(www.amap.com) with Fiddler, but I got this HTTP connect method, which is not viewable. There are icons of locks next to the URL and in 'Response' it says this:
'Encrypted HTTPS traffic flows through this CONNECT tunnel. HTTPS Decryption is enabled in Fiddler, so decrypted sessions running in this tunnel will be shown in the Web Sessions list.'
I found a solution suggesting that customizing rules in fiddler may help, so I followed and added this to its script:
if (oSession.oRequest[‘User- Agent’].IndexOf("Android") > -1 && oSession.HTTPMethodIs("connect")) {
oSession.oResponse.headers["Connection"]="Keep-Alive";
}
The changes to Fiddler Script
But of course, it didn't work, I've tried both iPhone and android and changed the header in the script respectively, none of them helped.
So is this app and HTTP connect method crawlable? The data is constructively helpful to my research, instead, it is not provided in website 'amap', so it has to be done through a cellphone.
If you have HTTPS decryption enabled in Fiddler but you see (mostly) only CONNECT requests this means that the apps on the device try to open a connection but do not trust the Fiddler root certificate.
If you try to use the apps on-device you will notice that there is currently no working network connection available (requests just don't work as the apps don't accept the server certificate created by Fiddler).
On Android devices since Andorid 6 you need root permissions to instal the Fiddler rot certificate or alternatively if you want to monitor a single app you can try to modify and re-sign the app. All details are described in this question and answer:
Some androids apps won't connect through fiddler
I'm trying to create a websocket connection to my Phoenix app from an Android client. I'm trying to use this library but I'm running into this issue and I'm unable to successfully join a channel.
Upon reviewing the source code of the above java phoenix client library, it looks like the initial request from the client to connect to the socket is made with http schema and not ws (the source code explicitly changes the provided url to make sure it always uses http). It's not clear to me how this would work without additional configuration in my Phoenix app: if a socket connect request is made to http://localhost:4000/socket, the request will fail because there is no route for /socket when the schema is http.
There's nothing in the library docs that says any additional config is required in my Phoenix app to make this work, but I don't see how it could work for the reason stated above.
Does a Phoenix app have built in handling for the connection upgrade, etc, required on handshake as specified here?
As a note, I have no issues making websocket connections from my javascript web client to my Phoenix backend.
Any suggestions are appreciated!
Have you tried using the default path for a channel http://localhost:4000/socket/websocket ?
I'm using Fiddler2 for checking and sniffing my apps request to rest server, It's work perfectly.
But in my last app I'm using Ion Library for Asynchronous Networking and Image Loading. When I create any request ( as POST -or- GET ), I can't monitor and see anything!!
Is anybody there that know how can handle this?! or cause of this issue?!
THanks
Did you follow the proxy configuration steps required? https://github.com/koush/ion#proxy-servers-like-charles-proxy
Ion.getDefault(context).configure().proxy("mycomputer", 8888);
You also need to ensure that Allow remote computers to connect setting is enabled in Tools > Fiddler Options > Connections.
Scenario: I am trying to debug an Android app by proxying requests through Fiddler.
I got FiddlerRoot certificate installed on the Android device, and the SSL decryption works for most requests, but for other requests I can only see the HTTPS Connect, and nothing else in the Fiddler log. I think it might be image requests over SSL that fails to decrypt.
I have double-checked that "Hide images" is off, etc. Images retrieved are hosted on another domain than the main API the app talks to.
What could cause this behaviour ? And how do I get the image requests to show in Fiddler ?
I am using the latest Fiddler4.
There are plenty of tutorials on how you can intercept HTTP(s) traffic from Android using Fiddler.
Try this one: http://docs.telerik.com/fiddler/configure-fiddler/tasks/configureforandroid
However, it will fail when you try to intercept and decrypt Android SSL traffic coming from an application, and not from a browser.
It might be that the application uses a certificate pinning – and you are probably cannot decipher this connection. Lost cause!
But more probably, the reason is a bug in the HttpsUrlConnection pipeline implementation.
To solve the issue, please proceed with the following steps:
In Fiddler click "Rules->Customize Rules";
Find function OnBeforeResponse in the script
Add following code to the function body:
if (oSession.oRequest["User-Agent"].indexOf("Dalvik") > -1 &&
oSession.HTTPMethodIs("CONNECT")) {
oSession.oResponse.headers["Connection"] = "Keep-Alive";
}
Save the file and restart Fiddler.
I am implementing twitter for android. When i am requesting for Request Token. It throws me this error:
04-27 11:25:01.163: DEBUG/ERROR=(3467): Host is unresolved: api.twitter.com:80
Before it was working fine. Suddenly it started giving this error.
Thanks in advance, aby
That sounds like a DNS lookup error. If you have a network tool suite installed that allows nameserver lookups (GTech Net Tools is one of these, and it's free) try entering api.twitter.com to see if your emulator can resolve the IP address.
One other thing to note is that you should be using HTTPS to call the OAuth resources at Twitter. From the :80 on your request, you can tell that whatever called oauth/request_token used plain old HTTP. All network communication involved in negotiating your OAuth tokens should be secured.
I understand that we can use HTTP as well(If your system lacks a security cert). You can tell the library to use HTTP call by adding the following line before the initializing the Twitter connection object.
System.setProperty("twitter4j.http.useSSL","false");
I had the same problem and after many tries it seems that the problem was in the emulator.. when trying the program on 1.5 it worked. However, it didn't work on 2.1. I opened the native emulator browser on 2.1 and it failed to load the google page (probably the emulator got an internet connection problem)