Exposing a service running on localhost to an Android emulator? - android

I'm running a service through ASP.net/Visual Studio that's being developed in conjunction with an Android app. When I run the service through VS, it's accessible at http://localhost:13980/ but not http://127.0.0.1:13980/ (which gives a "bad request - invalid hostname" 400 error). Obviously, I can't tell the Android app to look for a service at "localhost" since that'll be pointing at itself.
I understand (according to this page) that the Android emulator treats 10.0.2.2 as a pass-through IP address to the host machine's 127.0.0.1, so it would stand to reason that everything would come together if I a) got localhost to be properly exposed through 127.0.0.1, and b) changed the target address in the app from localhost:port to 10.0.2.2:port.
How would I go about doing part A? I'm running Windows 8.1 Pro, Visual Studio 2012, and the project in question is targeting .NET 4.5.
Thanks!

You have two options:
Run the web service under IIS instead of VS Cassini. This way you can bind the web service to your local network's IP address, e.g. http://10.0.2.2:8081
Modify the hosts file on your Android emulator to redirect localhost to your computer's IP address
The second one isn't a great solution. It may cause some conflicts with the OS and I'm not even sure Cassini would still even serve the request. Visual Studio's in-built web server (Cassini) only listens to local requests, so option (1) really is the most flexible. Plus, since you have W8 Pro IIS is already built-in.

The IP address 10.0.2.2 IP maps to the the 127.0.0.1 IP address, not to localhost.
From the emulator, connect to 10.0.2.2, and then host your site on 127.0.0.1 instead of localhost. That should work.

Use the IP address 10.0.2.2 instead. See this:
How to connect to my http://localhost web server from Android Emulator in Eclipse

Related

failled to access to localhost using volley library [duplicate]

What can I do in the Android emulator to connect it to my localhost web server page at http://localhost or http://127.0.0.1?
I've tried it, but the emulator still takes my request like a Google search for localhost or worse it says that it didn't found the page while my web server is normally running.
The localhost refers to the device on which the code is running, in this case the emulator.
If you want to refer to the computer which is running the Android simulator, use the IP address 10.0.2.2 instead.
You can read more from here.
Use 10.0.2.2 for default AVD and 10.0.3.2 for genymotion.
I used 10.0.2.2 successfully on my home machine, but at work, it did not work. After hours of fooling around, I created a new emulator instance using the Android Virtual Device (AVD) manager, and finally the 10.0.2.2 worked.
I don't know what was wrong with the other emulator instance (the platform was the same), but if you find 10.0.2.2 does not work, try creating a new emulator instance.
Try http://10.0.2.2:8080/ where 8080 is your port number. It worked perfectly. If you just try 10.0.2.2 it won't work. You need to add port number to it. Also if Microsoft IIS has been installed try turning off that feature from control panel (if using any windows os) and then try as given above.
You can actually use localhost:8000 to connect to your machine's localhost by running below command each time when you run your emulator (tested on Mac only):
adb reverse tcp:8000 tcp:8000
Just put it to Android Studio terminal.
It basically sets up a reverse proxy in which a http server running on your phone accepts connections on a port and wires them to your computer or vice versa.
according to documentation:
10.0.2.2 - Special alias to your host loopback interface (i.e., 127.0.0.1 on your development machine)
check Emulator Networking for more tricks on emulator networking.
For My Mac OS mountain Lion device :
http://10.0.2.2:8888
Works perfect !
If you using Android Emulator :
You can connect to your Pc localhost by these IPs :
10.0.2.2:{port of your localhost} => if you set your machine port in xamp you must use that port . In my case 10.0.2.2:2080
Also you can use your network adapter IP .In CMD write ipconfig and find your adapter ip address :
If emulator can not connect to this IPs close the emulator an open it by cold boot from AVD Manager :
If you using Genymotion :
You can connect to machine localhost by this IP : 10.0.3.2:{port number}
Or your adapter IP address as I explained above: in my case : 192.168.1.3:2080
I needed to figure out the system host IP address for the emulator "Nox App Player". Here is how I figured out it was 172.17.100.2.
Installed Android Terminal Emulator from the app store
Issue ip link show command to show all network interfaces. Of particular interest was the eth1 interface
Issue ifconfig eth1 command, shows net as 172.17.100.15/255.255.255.0
Begin pinging addresses starting at 172.17.100.1, got a hit on `172.17.100.2'. Not sure if a firewall would interfere but it didn't in my case
Maybe this can help someone else figure it out for other emulators.
Allowing PWA installation
First of all, install the Android debug bridge:
$ sudo apt install adb android-sdk-platform-tools-common
Start your Android emulator as usual, e.g.:
$ ~/Android/Sdk/emulator/emulator -avd Pixel_3a_API_30_x86
Only then, configure a reverse proxy on the bridge of the Android emulator that will forward localhost HTTP requests to the appropriate port (e.g. 8000) of the localhost server running on your host computer and vice versa:
$ adb reverse tcp:8000 tcp:8000
A progressive web application (PWA) being served on localhost:8000
or 127.0.0.1:8000 will be installable and connect to its service-worker.js. Whereas PWA installation is not allowed from IP address 10.0.2.2.
Caveat: adb reverse tcp:8000 tcp:8000 needs to be reissued after each Android emulator evocation.
Hence, a bash script to launch an Android emulator, followed by a reverse proxy, would look like this:
#!/usr/bin/env bash
$HOME/Android/Sdk/emulator/emulator -avd Pixel_3a_API_30_x86 > /dev/null 2>&1
adb reverse tcp:8000 tcp:8000
The accepted answer is correct, but didn't work in my case. I had to create the virtual device with the company VPN-client on the host machine turned off. This is quite understandable as many company networks use adresses starting with 10 (private network range), which could interfere with the special address 10.0.2.2
If you are in windows you can go to simbol system and write ipconfig and check what ip is assigned to your machine.
FOR ANYONE TRYING TO REACH A LOCAL IIS Server (ASP.NET)
For me, the accepted answer was not enough. I had to add a binding for 127.0.0.1 in the applicationhost.config, which was at the root of my ASP.NET solution.
Despite reading all the answers here and elsewhere, I have lost several hours trying to debug this issue, as the address 10.0.2.2 did not work, even in Chrome browser. If the same is happening to you, here is a step-by-step guide to try to debug and hopefully fix your issue.
Check emulator gateway is 10.0.2.2
Inside the emulated Android, go to Settings > WiFi, check if it is connected to AndroidWiFi hotspot (which represents your host computer), and then click on Advanced at the bottom, then check the Gateway address: it should point to 10.0.2.2 . If not, then you have another issue, maybe changing proxy settings can fix your issue, see here how to do that with Android Studio since 2022, as the proxy setting is now hidden away: How to configure proxy in emulators in new versions of Android Studio?
Check if your server is accessible from your host computer
Simply open a web browser and type http://localhost:<port> to see if your local web app is accessible. If not, then you likely have an issue with your local server parameters.
Check if your server is accessible from the emulator
Open Chrome browser, and point it to http://10.0.2.2:<port> (for genymotion, replace with http://10.0.3.2:<port>). If your web app shows up, great, you're done. If not, then test the other steps below to pinpoint the root issue.
Test with another server
In case your web app can be accessed from your host computer, but not inside the emulator, the root cause can be that your local server is restricting access to some interfaces for some reason, likely for security reasons.
To check this, try to use another server, just a simple HTTP server will do, such as http-server with nodejs, or python -m http.server 8000 with Python 3.
Then, try to access this simple server from your emulator's Chrome browser, eg, http://10.0.2.2:8000. If it works, then this confirms that your local server is restricting access to some interfaces. You need to read your local server's documentation to broaden permissions.
For example, in my case, my server was angular-cli (AngularJS), which by default restricts serving only to localhost. To make it work, I had to use ng serve --disable-host-check --host 0.0.0.0 instead of just ng serve, as suggested in this other question. The --host 0.0.0.0 instructs the webserver to serve all interfaces. Similar arguments can be provided to most webservers.
An alternative might be to disable some unused adapters, especially virtual ones such as VPNs.
Your Android app permissions to cleartext
Now, your web app should be accessible from inside the emulator, using Chrome app, with the URL http://10.0.2.2:<port>. The last piece of the puzzle is to add permissions in your Android app to access 10.0.2.2 and especially cleartext if your local webserver is not equipped with a SSL certificate (the most likely scenario for a local development webserver - just check if https://localhost:<port> works or only http://localhost:<port> from the host computer). This will allow your Android app to access your local webserver, just like Chrome does.
Adding specific permissions to access cleartext (ie, http://) from your Android app is necessary since Android 9 (API 28) upwards. There are several ways to configure your Android app to add this permission, see: https://stackoverflow.com/a/50834600/1121352
Conclusion
Accessing the host from the Android emulator can be tricky, but by careful step-by-step debugging, it can be possible to overcome the issue in most cases.
A last alternative, probably faster, is to get a paid subscription to services such as ngrok, but the free version is useless as they necessarily open the webapp in a web browser, outside of your Android app's webview.
I do not know, maybe this topic is already solved, but when I have tried recently do this on Windows machine, I have faced with lot of difficulties.
So my solution was really simple. I have downloaded this soft
http://www.lenzg.net/rinetd/rinetd.html followed their instructions about how to make port forwarding and then successfully my android device connected to make asp.net localhost project and stopped on my breaking point.
my rinetd.conf file:
10.1.1.20 1234 127.0.0.1 1234
10.1.1.20 82 127.0.0.1 82
Where 10.1.1.20 is my localhost ip, 82 and 1234 my ports
Also I have craeted bath file
for easy life yournameofbathfile.bat, put that file inside rinedfolder. My bath file:
rinetd.exe -c rinetd.conf
After starting this soft, start your aps.net server and try to access from android device or any device in your local network(for example Computer ABC starts putty) and you will see that everything works. No need to go to router setting or do any other complicated things.
I hope this will help you. Enjoy.
Another workaround is to get a free domain from no-ip.org and point it to your local ip address.
Then, instead of using http://localhost/yourwebservice you can try http://yourdomain.no-ip.org/yourwebservice
I know this is old, but if you find that 10.0.2.2 is not working as the computer IP, follow these instructions to find it

Ip Address Of Machine From Android Emulator

I am using an emulator and a local server to run a certain app.
Because it is a school project I need to show the app to a tester and then the app would be checked by a different tester without me showing it.
As the app needs to call the local server it needs to know the ip of the machine running the server.
How can the emulator gain the ip of the machine running it?
Tried using LocalHost and 127.0.0.1 instead if the ip address 10.0.0.10 that I had but it didn't work.
The localhost refers to the device on which the code is running, in this case, the emulator.
If you want to refer to the computer which is running the Android simulator, use the IP address 10.0.2.2 instead. You can read more from here.

How to connect to a local server from an android emulator?

Started a local server in my computer with IP 127.0.0.1 listening on port 3000.
However, I am unable to access it via my android app when I run the emulator on android studio. I got a timeout error from my app's networking library, so it is not making connection.
Use the IP address 10.0.2.2. You can read more at here.
On each Android emulator Android Studio runs a router for it in order to isolate the emulated device from your development system. Thus in order to access a local server running on your development system (your laptop, desktop, etc) you must use the special IP of 10.0.2.2 and the port the server is listening on. To learn more read this page.

Android Simulator how does it connect to local IP addresses?

I am trying to implement an Android application in Windows 7 using Eclipse. I am trying to connect the Android simulator to the local test server in my company, but for some reason, it cannot connect to the test server.
If there is any settings or configurations for this, please let me know.
I have tried to do the same from a MAC machine using iPhone emulator and I am facing the same problem. How would this emulator connect to the local servers in my company as currently it all goes to live servers? What configurations are required to be done on the simulators, and how?
If I try to connect to the test server from normal Windows machine browser, I am able to successfully connect to it through the web browser; but when I try to do the same from the Android emulator browser, it cannot connect to it.
The emulator points to the live network and not the local network in my company. This is strange and I know that I need to do some settings for it, but I am not sure where these settings are done and how.
If accessing local computer:
http://localhost:8080/MyLocalServer.html // URL to use in computer browser
http://10.0.2.2:8080/MyLocalServere.html // URL to use in emulator browser
Also try using a local IP to connect to any local servers. Do not use host names.
Dont:
http://mylocalserver.org/
Do:
http://192.168.1.125:portnumber
You have to set up IP-based hosts instead of name-based.
Emulator its - VM. This use virtual network connection. I think you need before chech this connection (this connection may bee stay as NAT, Breedge, Native IP adress, Proxy).
Since you do not work iPhone emulator, most likely you, IP adress virtual network connectionб which uses Emulator, does not match the address area of the local network, and routing occurs
This may help you...
Taken from the android docs:
If you need to refer to your host computer's localhost, such as when you want the emulator client to contact a server running on the same host, use the alias 10.0.2.2 to refer to the host computer's loopback interface. From the emulator's perspective, localhost (127.0.0.1) refers to its own loopback interface.
http://developer.android.com/guide/faq/commontasks.html#localhostalias

libcurl & android connecting to a web service at localhost

I've managed to connect my app to a web service but I have a problem with the android platform. (If someone doesn't know, with cocos2d-x you can make multiplatform apps)
Right now, the web service is hosted at "http://127.0.0.1:9876/ts?wsdl" at localhost.
I've managed to generate requests for it and it works great in the win32 app. The problem comes when I try to connect to the web service with the android app. It will always give "code: 7" (couldn't connect) but the funny thing is that it will work if I connect to whatever hosted server.
So I wonder why it won't let me connect to localhost, also note that I'm using the emulator since I don't have a device but I don't think that's the problem.
Any ideas?
I assume you are using an emulator instead of a phone. So when you type localhost, it refers to the ip address of the phone, not your pc. Android provides you an ip address which maps to your PCs localhost. So use 10.0.2.2. instead of localhost and it should work.

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