Serializaçao

public static void copyFile(File source, File destination) throws IOException {
   if (destination.exists()) {
      destination.delete();
   }

   FileChannel sourceChannel = new FileInputStream(source).getChannel();
   FileChannel destinationChannel = new FileOutputStream(destination).getChannel();
   sourceChannel.transferTo(0, sourceChannel.size(), destinationChannel);
   sourceChannel.close();
   destinationChannel.close();
}

public class TesteObjeto {

    public static void main(String[] args) {
        File arquivo = new File("C:/Documents and Settings/André Justi/Desktop/tester", "exemplo.aluno");
        if (arquivo.exists()) {
            try {
                FileInputStream fis = new FileInputStream(arquivo);
                ObjectInputStream ois = new ObjectInputStream(fis);
                Aluno aluno = (Aluno) ois.readObject();
                System.out.println("Nome.........:   " + aluno.getNome());
                System.out.println("Email........:   " + aluno.getEmail());
                System.out.println("Turma........:   " + aluno.getTurma());
                System.out.println("Mensalidade..:   " + aluno.getMensalidade());
                System.out.println("Desconto.....:   " + aluno.getDesconto());
            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
            System.out.println("Não existe arquivo de aluno!");
        }
        Random ranron = new Random();
        Aluno aluno = new Aluno();
        aluno.setEmail("[email removido]");
        aluno.setNome("Aluno ");
        aluno.setTurma("2008-1");
        aluno.setMensalidade(ranron.nextFloat() * 100);
        aluno.setDesconto(aluno.getMensalidade() * 0.12f);
        try {

            FileOutputStream fos = new FileOutputStream(arquivo);
            ObjectOutputStream oos = new ObjectOutputStream(fos);
            oos.writeObject(aluno);
            oos.flush();
            oos.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}