import java.util.ArrayList;
import java.util.List;

public class Test {

  public static void main(String[] args) {
    // test data
    String[] t = {"    22 20 23 ", "50 56", "a b c", "1 2 3", "1 -2 3", " "};
    List<Integer> list = convert(t); // convert it
    for (Integer i : list) // check
    {
      System.out.println(i);
    }
    /*
     java.lang.NumberFormatException: For input string: "abc"
     java.lang.NumberFormatException: For input string: "1-23"
     java.lang.NumberFormatException: For input string: ""
     222023
     5056
     123
     */

  }

  static List<Integer> convert(String[] values) {
    // make empty list of Integer
    List<Integer> list = new ArrayList<>();
    for (String s : values) // each array element
    {
      String temp = s.replaceAll(" ", ""); // remove spaces
      try {
        int i = Integer.parseInt(temp); // change to an int
        list.add(i); // put in list - uses autoboxing - Integer not int
      } catch (NumberFormatException nfe) // in case not valid integer
      {
        System.out.println(nfe);
      }
    }
    return list;
  }

}