public class Messager implements Runnable { public static void main(String[] args) { new Thread(new Messager("Wallace")).start(); new Thread(new Messager("Gromit")).start(); } private String name; public Messager(String name) { this.name = name; } public void run() { message(1); message(2); } private synchronized void message(int n) { System.out.print(name + "-" + n + " "); }}