Какие знаешь базовые реализации OutputStream

try (OutputStream os = new FileOutputStream("file.txt")) {
    os.write("Hello".getBytes());
}

ByteArrayOutputStream baos = new ByteArrayOutputStream();
baos.write(65); // 'A'
byte[] bytes = baos.toByteArray();

OutputStream bos = new BufferedOutputStream(new FileOutputStream("file.txt"));
bos.write("Buffered".getBytes());
bos.flush();

ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("obj.dat"));
oos.writeObject(new MyClass());