How do you validate an IP address on Android?

user_399046 0
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I am using simple socket communication between Android (as the client) and PC (as the server). I am having the user input the IP address into an EditText field and I want to validate the IP address. How do you validate an IP address on Android?

android
5 Answers

Reading description about Patterns.IP_ADDRESS I've seen that it's will be deprecated (on API 31) and needs use another function (InetAddresses.isNumericAddress) for check ip adress.

The result:

fun isIpValid(ip: String): Boolean {
    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
        InetAddresses.isNumericAddress(ip)
    } else {
        Patterns.IP_ADDRESS.matcher(ip).matches()
    }
}
user_76996170

The solution in Kotlin to find a Valid IP:

import java.util.regex.*;
 ...
 ...
    fun isValidIPAddress(ip:String):Boolean {
      // Regex for digit from 0 to 255
      val reg0To255 = ("(\\d{1,2}|(0|1)\\" + "d{2}|2[0-4]\\d|25[0-5])")
      // regex 0 To 255 followed by a dot, 4 times repeat
      // validation an IP address.
      val regex = (reg0To255 + "\\."
                   + reg0To255 + "\\."
                   + reg0To255 + "\\."
                   + reg0To255)
      val p = Pattern.compile(regex)
      val m = p.matcher(ip)
      return m.matches()
    }
    
    val inputIP = "127.1.1.775"
    println("Input: " + inputIP)
    println("Output: " + isValidIPAddress(inputIP))
    
 ...
 ...

Input: 127.1.1.055 Output: true

Input: 127.ip.1.75 Output: false

Input: 127.201.1.775 Output: false

user_13529190
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