The Avro documentation page has an example that write multiple avro objects into a file:

DatumWriter<User> userDatumWriter = new SpecificDatumWriter<User>(User.class);
DataFileWriter<User> dataFileWriter = new DataFileWriter<User>(userDatumWriter);
dataFileWriter.create(user1.getSchema(), new File("users.avro"));
dataFileWriter.append(user1);
dataFileWriter.append(user2);
dataFileWriter.append(user3);
dataFileWriter.close();

I would like to achieve something similar but write to a ByteArrayOutputStream.

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
Encoder encoder = EncoderFactory.get().binaryEncoder(outputStream, null);
DatumWriter<MyData> myDataDatumWriter = new SpecificDatumWriter<>(MyData.getClassSchema());

myDataDatumWriter.write(myData1, encoder);
encoder.flush();
myDataDatumWriter.write(myData2, encoder);
encoder.flush();

I sent the data in the output stream as a http response, but the data cannot be deserialized on the client side because it is not a recognizable avro format.

What’s wrong with this code?