public class TestHashCode {

 public static void main(String[] args) {
  String s = "OK";
  StringBuffer s1 = new StringBuffer(s);
  System.out.println("s hashcode:" + s.hashCode() + "--- s1.hashcode:" + s1.hashCode());

  String s2 = new String("OK");
  StringBuffer s3 = new StringBuffer(s2);
  System.out.println("s2 hashcode:" + s2.hashCode() + "--- s3.hashcode:" + s3.hashCode());
  System.out.println(s.equals(s1));

 }

}