I am developing an app in which I need to scans WiFi network and display the list of all connected devices.
Allow a use to tap on a device and the app should show all the hardware info of that particular device. Here by hardware I mean - RAM, Storage Media, Storage Capacity, Device Name, Device IP address, etc.
Now this device can be anything like xbox, a laptop with Linux/Windows, mobile phone like iPhone or any Andorid based smart phone or even a printer.
How can I scans WiFi network and query/detect all the devices attached to it?
What are the protocols that I need to use to get list of hardware in a particular device irrespective of the OS running on it?
Maybe the Network Discovery github project could help you. It lists all users connected to WiFi with IP and MAC addresses and gathers even some information like open ports, device name, ping, etc. Hope it helps
Check requestPeers of WifiP2pManager
As per documents it seeks PeerListListener which returns WifiP2pDeviceList carrying list of WifiP2pDevice which carries deviceAddress, deviceName, primaryDeviceType, secondaryDeviceType, status and other attributes.
In my opinion, you can use Wi-Fi Peer-to-Peer
https://developer.android.com/guide/topics/connectivity/wifip2p.html
"Wi-Fi peer-to-peer (P2P) allows Android 4.0 (API level 14) or later devices with the appropriate hardware to connect directly to each other via Wi-Fi without an intermediate access point (Android's Wi-Fi P2P framework complies with the Wi-Fi Alliance's Wi-Fi Direct™ certification program). Using these APIs, you can discover and connect to other devices when each device supports Wi-Fi P2P, then communicate over a speedy connection across distances much longer than a Bluetooth connection. This is useful for applications that share data among users, such as a multiplayer game or a photo sharing application." Blockquote
来源：https://stackoverflow.com/questions/12386948/how-to-detect-all-the-devices-connected-in-a-wifi-network-from-android-app