/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
import java.util.stream.* ;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		IntStream codePoints = String.valueOf( 1_234 ).codePoints() ;
 
    List< Integer > digits = 
            codePoints
                    .filter( Character :: isDigit )
                    .mapToObj( Character :: toString )
                    .map( Integer :: valueOf )
                    .collect( Collectors.toList() )   // In Java 16+, replace with .toList() 
    ;
 
        System.out.println( digits ) ;
	}
}

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