20190501.contract.cs

internal sealed class PhoneBook {
  private String m_pathname; // path name of file containing the address book
  
  // Other methods go here.
  public String GetPhoneNumber(String name) {
    String phone;
    FileStream fs = null;
    try {
      fs = new FileStream(m_pathname, FileMode.Open);
      // Code to read from fs until name is found goes here
      phone = /* the phone # found */
    }
    catch (FileNotFoundException e) {
      // Throw a different exception containing the name, and
      // set the originating exception as the inner exception.
      throw new NameNotFoundException(name, e);
    }
    catch (IOException e) {
      // Throw a different exception containing the name, and
      // set the originating exception as the inner exception.
      throw new NameNotFoundException(name, e);
    }
    finally {
      if (fs != null) {
        fs.Close();
      }
    }
    
   return phone;
  }
}