Examples with ProtocolMessageUnmarshaller org.apache.nifi.cluster.protocol.ProtocolMessageUnmarshaller used on opensource projects

Example 1 with ProtocolMessageUnmarshaller

use of org.apache.nifi.cluster.protocol.ProtocolMessageUnmarshaller in project nifi by apache.

the class JaxbProtocolContext method createUnmarshaller.

@Override
public ProtocolMessageUnmarshaller<T> createUnmarshaller() {
    return new ProtocolMessageUnmarshaller<T>() {

        @Override
        public T unmarshal(final InputStream is) throws IOException {
            try {
                final DataInputStream dis = new DataInputStream(is);
                // check for the presence of the message protocol sentinel
                final byte sentinel = (byte) dis.read();
                if (sentinel == -1) {
                    throw new EOFException();
                }
                if (MESSAGE_PROTOCOL_START_SENTINEL != sentinel) {
                    throw new IOException("Failed reading protocol message due to malformed header");
                }
                // read the message size
                final int msgBytesSize = dis.readInt();
                // read the message
                final ByteBuffer buffer = ByteBuffer.allocate(msgBytesSize);
                int totalBytesRead = 0;
                do {
                    final int bytesToRead;
                    if ((msgBytesSize - totalBytesRead) >= BUF_SIZE) {
                        bytesToRead = BUF_SIZE;
                    } else {
                        bytesToRead = msgBytesSize - totalBytesRead;
                    }
                    totalBytesRead += dis.read(buffer.array(), totalBytesRead, bytesToRead);
                } while (totalBytesRead < msgBytesSize);
                // unmarshall message and return
                final Unmarshaller unmarshaller = jaxbCtx.createUnmarshaller();
                final byte[] msg = new byte[totalBytesRead];
                buffer.get(msg);
                final XMLStreamReader xsr = XmlUtils.createSafeReader(new ByteArrayInputStream(msg));
                return (T) unmarshaller.unmarshal(xsr);
            } catch (final JAXBException | XMLStreamException e) {
                throw new IOException("Failed unmarshalling protocol message due to: " + e, e);
            }
        }
    };
}