Android TextUtils.isDigitsOnly returns true for empty string

As Selvin mentioned correctly this is actually a bug that persists until today. See here.

You can get around that by doing this:

Java

boolean myIsDigitsOnly(String str) {
    return str.isEmpty() && TextUtils.isDigitsOnly(str); 
}

Now you call your own custom method:

myIsDigitsOnly(""); // returns false

Kotlin

In Kotlin, you don't need TextUtils at all. Just create your own extension function like this:

fun String.isDigitsOnly() = all(Char::isDigit) && isNotEmpty()

Try it out here!

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_{Thanks to silwar who inspired me to make the Java one more concise.}

For Kotlin Users

Although its an old question with accepted answer, this is suggestion to improve this answer in Kotlin language by following code

fun String.myIsDigitsOnly(): Boolean {
   return TextUtils.isDigitsOnly(this) && this.isNotEmpty()
}

Now you can call your method like

"".myIsDigitsOnly() // returns false

or

"123523423".myIsDigitsOnly() // returns false