Another server you can try http://tjws.sf.net, actually it already provides Android enabled version.
If you are using kotlin,consider these library. It's build for kotlin language.
AndroidHttpServer is a simple demo using ServerSocket to handle http request
https://github.com/weeChanc/AndroidHttpServer
https://github.com/ktorio/ktor
AndroidHttpServer is very small , but the feature is less as well.
Ktor is a very nice library,and the usage is simple too
You can try Restlet edition for android:
The source can be downloaded from Restlet website:
NanoHttpd works like a charm on Android -- we have code in production, in users hands, that's built on it.
The license absolutely allows commercial use of NanoHttpd, without any "viral" implications.
This can be done using ServerSocket, same as on JavaSE. This class is available on Android. android.permission.INTERNET is required.
The only more tricky part, you need a separate thread wait on the ServerSocket, servicing sub-sockets that come from its accept method. You also need to stop and resume this thread as needed. The simplest approach seems to kill the waiting thread by closing the ServerSocket.
If you only need a server while your activity is on the top, starting and stopping ServerSocket thread can be rather elegantly tied to the activity life cycle methods. Also, if the server has multiple users, it may be good to service requests in the forked threads. If there is only one user, this may not be necessary.
If you need to tell the user on which IP is the server listening,use NetworkInterface.getNetworkInterfaces(), this question may tell extra tricks.
Finally, here there is possibly the complete minimal Android server that is very short, simple and may be easier to understand than finished end user applications, recommended in other answers.
Source: Stackoverflow.com