Question

Let’s say I have a serializable class AppMessage.

I would like to transmit it as byte[] over sockets to another machine where it is rebuilt from the bytes received.

How could I achieve this?

Answer 1

Prepare the byte array to send:

static byte[] serialize(final Object obj) {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();

    try (ObjectOutputStream out = new ObjectOutputStream(bos)) {
        out.writeObject(obj);
        out.flush();
        return bos.toByteArray();
    } catch (Exception ex) {
        throw new RuntimeException(ex);
    }
}

Create an object from a byte array:

static Object deserialize(byte[] bytes) {
    ByteArrayInputStream bis = new ByteArrayInputStream(bytes);

    try (ObjectInput in = new ObjectInputStream(bis)) {
        return in.readObject();
    } catch (Exception ex) {
        throw new RuntimeException(ex);
    }
}