program to count spaces in a string

import java.io.*;

class Space
{
static String s;
  int l=s.length();
  int n=0;
  int i;
  public int lack(String x)
  {
  String c;
  c=x;
  for(i=0;i<l;i++)
  {
  char ch=c.charAt(i);
  if(ch==' ')
  {
  n++;
  }
  }
  return n;
  }

public static void main(String args[]) throws IOException
{
DataInputString z=new DataInputString(System.in);
String x;
System.out.println(enter string");
x=z.readLine();
Space m= new Space();

int l=m.lack(s);
System.out.println("number of spaces are" +l);
}
}