Itchy problem

import java.io.*;

class DataIO {
        public static void main(String args[]) {
                FileOutputStream f;
                try {
                        f = new FileOutputStream("test");
                } catch (FileNotFoundException fe) {
                        System.out.println(fe);
                        System.exit(1);
                }
                DataOutputStream d = new DataOutputStream(f);
                try {
                        d.writeDouble(7.6d);
                        d.writeFloat(90.9f);
                        d.writeChars("Ravi");
                        d.close();
                        f.close();
                } catch (IOException ioe) {
                        System.out.println(ioe);
                        System.exit(2);
                }
        }
}

Gives the error:
  DataIO.java:12: variable f might not have been initialized
                DataOutputStream d = new DataOutputStream(f);
                                                          ^

How to resolve this problem.