JAXB hangs while unmarshaling socket stream

问题

Have an issue with marshall and unmarshall readers and writers. So here it is. This is how i marshall something to the PrintWriter.

try {

    JAXBContext jaxbContext = JAXBContext.newInstance(XMLProtocol.class);
    Marshaller jaxbMarshaller = jaxbContext.createMarshaller();
    //jaxbMarshaller.setProperty(, value)
    //jaxbMarshaller.setProperty(Marshaller.JAXB_FRAGMENT, true);
    jaxbMarshaller.marshal(protocol, out);


} catch (JAXBException e) {
    LOG.error("Error while processing protocol"+e);             
}

This is how i get it:

private BufferedReader in;
private PrintWriter out;
private String buffer;
private StringBuffer stringBuffer;

public ServerThread(Socket s) throws IOException {
    socket = s;
    in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
    start();
}

public void run() {
    try {
        while (true) {
            // LOG.trace("Waiting for input stream ready");

            /*
             * if (in.readLine().endsWith(">")) {
             *     LOG.trace("here we go"+buffer);
             *     JAXBContext jaxbContext = JAXBContext.newInstance(XMLProtocol.class);
             *     Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
             *     XMLProtocol protocol = (XMLProtocol) jaxbUnmarshaller.unmarshal(in);
             *     LOG.trace("Nop it no the end " + protocol.getContent());
             * }
             */

            if (in.ready()) {

                LOG.trace("BufferedReader - ready");
                buffer += in.readLine();
                if (buffer.endsWith("</XMLProtocol>")) {
                    LOG.trace("Wish you were here1"+in);

                    JAXBContext jaxbContext = JAXBContext.newInstance(XMLProtocol.class);

                    Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

                    XMLProtocol protocol = (XMLProtocol) jaxbUnmarshaller.unmarshal(in);

                    LOG.trace("Getting message from user " + protocol.getContent());
                } else {

                    LOG.trace("Nop it no the end " + buffer);
                }
            }
        }

    } catch (IOException e) {
        e.printStackTrace();

    } catch (JAXBException e) {
        e.printStackTrace();

    } finally {
        try {
            socket.close();
            LOG.trace("Socket closed");
        } catch (IOException e) {
            LOG.error("Socket no closed" + e);
        }
    }
}

Then this Unmarshall operation hangs. And it show me nothing even Exception.

回答1:

Yeah i found solvation of this issue! JAXB is not the best decision to SOCKET streams, cause it wait the end of the stream. Solution is to use clear SAX parser where you can to write your own ParserHandler (DefaultHandler.class) and when you reach your last tag, you should to throw your own exception which indicates to stop parsing.

来源：https://stackoverflow.com/questions/10949813/jaxb-hangs-while-unmarshaling-socket-stream

标签

jaxb

unmarshalling