JAVA-How to write data to a binary file?

Here is my code. I want to write to binary file! any ideas?

public void saveData(File file) throws IOException{ FileOutputStream foss = new FileOutputStream("Database.txt"); ObjectOutputStream ooss= new ObjectOutputStream(foss); Student[] studentsarray = students.toArray(new Student[students.size()] ); ooss.writeObject(studentsarray); ooss.close();

}}