org.taverna.server.master.common.Workflow.java Source code

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Here is the source code for org.taverna.server.master.common.Workflow.java

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/*
 * Copyright (C) 2010-2011 The University of Manchester
 * 
 * See the file "LICENSE.txt" for license terms.
 */
package org.taverna.server.master.common;

import static javax.xml.bind.Marshaller.JAXB_ENCODING;
import static javax.xml.bind.Marshaller.JAXB_FORMATTED_OUTPUT;
import static org.apache.commons.logging.LogFactory.getLog;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.Externalizable;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Serializable;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterInputStream;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlAnyElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;

import org.w3c.dom.Element;

/**
 * Encapsulation of a T2flow document.
 * 
 * @author dkf
 */
@XmlRootElement(name = "workflow")
@XmlType(name = "Workflow")
public class Workflow implements Serializable, Externalizable {
    /**
     * Literal document.
     */
    @XmlAnyElement(lax = true)
    public Element[] content;

    private static Marshaller marshaller;
    private static Unmarshaller unmarshaller;
    private final static String ENCODING = "UTF-8";
    static {
        try {
            JAXBContext context = JAXBContext.newInstance(Workflow.class);
            marshaller = context.createMarshaller();
            unmarshaller = context.createUnmarshaller();
            marshaller.setProperty(JAXB_ENCODING, ENCODING);
            marshaller.setProperty(JAXB_FORMATTED_OUTPUT, false);
        } catch (JAXBException e) {
            getLog("Taverna.Server.Webapp").fatal("failed to build JAXB context for working with " + Workflow.class,
                    e);
        }
    }

    public static Workflow unmarshal(String representation) throws JAXBException {
        StringReader sr = new StringReader(representation);
        return (Workflow) unmarshaller.unmarshal(sr);
    }

    public String marshal() throws JAXBException {
        StringWriter sw = new StringWriter();
        marshaller.marshal(this, sw);
        return sw.toString();
    }

    @Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        try {
            int len = in.readInt();
            byte[] bytes = new byte[len];
            in.readFully(bytes);
            Reader r = new InputStreamReader(new InflaterInputStream(new ByteArrayInputStream(bytes)), ENCODING);
            Workflow w = (Workflow) unmarshaller.unmarshal(r);
            r.close();
            this.content = w.content;
            return;
        } catch (JAXBException e) {
            throw new IOException("failed to unmarshal", e);
        } catch (ClassCastException e) {
            throw new IOException("bizarre result of unmarshalling", e);
        }
    }

    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            OutputStreamWriter w = new OutputStreamWriter(new DeflaterOutputStream(baos), ENCODING);
            marshaller.marshal(this, w);
            w.close();
            byte[] bytes = baos.toByteArray();
            out.writeInt(bytes.length);
            out.write(bytes);
        } catch (JAXBException e) {
            throw new IOException("failed to marshal", e);
        }
    }
}