org.nakedobjects.plugins.xstream.shared.XStreamMarshaller Maven / Gradle / Ivy

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package org.nakedobjects.plugins.xstream.shared;

import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.StreamCorruptedException;
import java.net.SocketException;

import org.apache.log4j.Logger;
import org.nakedobjects.metamodel.commons.exceptions.NakedObjectException;
import org.nakedobjects.remoting.command.shared.marshal.ConnectionException;
import org.nakedobjects.remoting.command.shared.marshal.IllegalRequestException;
import org.nakedobjects.remoting.command.shared.marshal.MarshallerAbstract;
import org.nakedobjects.remoting.command.shared.requests.Request;

import com.thoughtworks.xstream.XStream;


public class XStreamMarshaller extends MarshallerAbstract {
    
    private static final Logger LOG = Logger.getLogger(XStreamMarshaller.class);
    private final XStream xstream = new XStream();
    private ObjectInputStream input;
    private ObjectOutputStream output;

    
    ////////////////////////////////////////////////////////
    // common Marshaller impl
    ////////////////////////////////////////////////////////

    public void openStreams(final InputStream input, final OutputStream output) throws IOException {
        this.output = new ObjectOutputStream(output);
        this.input = new ObjectInputStream(input);
    }

    ////////////////////////////////////////////////////////
    // ServerMarshaller impl
    ////////////////////////////////////////////////////////

    public Object request(final Request request) throws IOException {
        final String requestData = xstream.toXML(request);
        if (LOG.isInfoEnabled()) {
            LOG.info("sending " + requestData.length() + " bytes of data");
        }
        try {
            if (LOG.isDebugEnabled()) {
                LOG.debug("sending request \n" + requestData);
            }
            try {
                output.writeObject(requestData);
            } catch (final SocketException e) {
                getOwner().reconnect();
                output.writeObject(requestData);
            }
            output.flush();
            final String responseData = (String) input.readObject();
            if (LOG.isDebugEnabled()) {
                LOG.debug("response received: \n" + responseData);
            }
            return xstream.fromXML(responseData);

        } catch (final StreamCorruptedException e) {
            try {
                final int available = input.available();
                if (LOG.isDebugEnabled()) {
                    LOG.debug("error in reading; skipping bytes: " + available);
                }
                input.skip(available);
            } catch (final IOException e1) {
                e1.printStackTrace();
            }
            throw new ConnectionException(e.getMessage(), e);
        } catch (final ClassNotFoundException e) {
            throw new ConnectionException("Failed request", e);
        }
    }

    
    ////////////////////////////////////////////////////////
    // ServerMarshaller impl
    ////////////////////////////////////////////////////////
    
    
    public Request awaitRequest() throws IOException {
        try {
            final String requestData = (String) input.readObject();
            if (LOG.isDebugEnabled()) {
                LOG.debug("request received \n" + requestData);
            }
            final Request request = (Request) xstream.fromXML(requestData);
            return request;
        } catch (final ClassNotFoundException e) {
            throw new IllegalRequestException("unknown class received; closing connection: " + e.getMessage(), e);
        }
    }

    public void sendError(final NakedObjectException exception) throws IOException {
        final String responseData = xstream.toXML(exception);
        sendData(responseData);
    }

    public void sendResponse(final Object response) throws IOException {
        final String responseData = xstream.toXML(response);
        sendData(responseData);
    }

    private void sendData(final String responseData) throws IOException {
        if (LOG.isDebugEnabled()) {
            LOG.debug("send response \n" + responseData);
        }
        output.writeObject(responseData);
        output.flush();
    }

}
// Copyright (c) Naked Objects Group Ltd.