didlparser.java

android_UPNP_DLNA_控制点

/*
 * Copyright (C) 2011 Teleal GmbH, Switzerland
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.teleal.cling.support.contentdirectory;

import org.teleal.cling.model.types.Datatype;
import org.teleal.cling.model.types.InvalidValueException;
import org.teleal.cling.support.model.DIDLAttribute;
import org.teleal.cling.support.model.DIDLContent;
import org.teleal.cling.support.model.DIDLObject;
import org.teleal.cling.support.model.DescMeta;
import org.teleal.cling.support.model.Person;
import org.teleal.cling.support.model.PersonWithRole;
import org.teleal.cling.support.model.ProtocolInfo;
import org.teleal.cling.support.model.Res;
import org.teleal.cling.support.model.StorageMedium;
import org.teleal.cling.support.model.WriteStatus;
import org.teleal.cling.support.model.container.Container;
import org.teleal.cling.support.model.item.Item;
import org.teleal.common.io.IO;
import org.teleal.common.util.Exceptions;
import org.teleal.common.xml.SAXParser;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.InputStream;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.URI;
import java.util.logging.Level;
import java.util.logging.Logger;

import static org.teleal.cling.model.XMLUtil.appendNewElement;
import static org.teleal.cling.model.XMLUtil.appendNewElementIfNotNull;

/**
 * DIDL parser based on SAX for reading and DOM for writing.
 * <p>
 * This parser requires Android platform level 8 (2.2).
 * </p>
 * <p>
 * Override the {@link #createDescMetaHandler(org.teleal.cling.support.model.DescMeta, org.teleal.common.xml.SAXParser.Handler)}
 * method to read vendor extension content of {@code <desc>} elements. You then should also override the
 * {@link #populateDescMetadata(org.w3c.dom.Element, org.teleal.cling.support.model.DescMeta)} method for writing.
 * </p>
 * <p>
 * Override the {@link #createItemHandler(org.teleal.cling.support.model.item.Item, org.teleal.common.xml.SAXParser.Handler)}
 * etc. methods to register custom handlers for vendor-specific elements and attributes within items, containers,
 * and so on.
 * </p>
 *
 * @author Christian Bauer
 * @author Mario Franco
 */
public class DIDLParser extends SAXParser {

    final private static Logger log = Logger.getLogger(DIDLParser.class.getName());

    /**
     * Uses the current thread's context classloader to read and unmarshall the given resource.
     *
     * @param resource The resource on the classpath.
     * @return The unmarshalled DIDL content model.
     * @throws Exception
     */
    public DIDLContent parseResource(String resource) throws Exception {
        InputStream is = null;
        try {
            is = Thread.currentThread().getContextClassLoader().getResourceAsStream(resource);
            return parse(IO.readLines(is));
        } finally {
            if (is != null) is.close();
        }
    }

    /**
     * Reads and unmarshalls an XML representation into a DIDL content model.
     *
     * @param xml The XML representation.
     * @return A DIDL content model.
     * @throws Exception
     */
    public DIDLContent parse(String xml) throws Exception {

        if (xml == null || xml.length() == 0) {
            throw new RuntimeException("Null or empty XML");
        }

        DIDLContent content = new DIDLContent();
        createRootHandler(content, this);

        log.fine("Parsing DIDL XML content");
        parse(new InputSource(new StringReader(xml)));
        return content;
    }

    protected RootHandler createRootHandler(DIDLContent instance, SAXParser parser) {
        return new RootHandler(instance, parser);
    }

    protected ContainerHandler createContainerHandler(Container instance, Handler parent) {
        return new ContainerHandler(instance, parent);
    }

    protected ItemHandler createItemHandler(Item instance, Handler parent) {
        return new ItemHandler(instance, parent);
    }

    protected ResHandler createResHandler(Res instance, Handler parent) {
        return new ResHandler(instance, parent);
    }

    protected DescMetaHandler createDescMetaHandler(DescMeta instance, Handler parent) {
        return new DescMetaHandler(instance, parent);
    }


    protected Container createContainer(Attributes attributes) {
        Container container = new Container();

        container.setId(attributes.getValue("id"));
        container.setParentID(attributes.getValue("parentID"));

        if ((attributes.getValue("childCount") != null))
            container.setChildCount(Integer.valueOf(attributes.getValue("childCount")));

        try {
            Boolean value = (Boolean)Datatype.Builtin.BOOLEAN.getDatatype().valueOf(
                    attributes.getValue("restricted")
            );
            if (value != null)
                container.setRestricted(value);

            value = (Boolean)Datatype.Builtin.BOOLEAN.getDatatype().valueOf(
                    attributes.getValue("searchable")
            );
            if (value != null)
                container.setSearchable(value);
        } catch (Exception ex) {
            // Ignore
        }

        return container;
    }

    protected Item createItem(Attributes attributes) {
        Item item = new Item();

        item.setId(attributes.getValue("id"));
        item.setParentID(attributes.getValue("parentID"));

        try {
            Boolean value = (Boolean)Datatype.Builtin.BOOLEAN.getDatatype().valueOf(
                    attributes.getValue("restricted")
            );
            if (value != null)
                item.setRestricted(value);

        } catch (Exception ex) {
            // Ignore
        }

        if ((attributes.getValue("refID") != null))
            item.setRefID(attributes.getValue("refID"));

        return item;
    }

    protected Res createResource(Attributes attributes) {
        Res res = new Res();

        if (attributes.getValue("importUri") != null)
            res.setImportUri(URI.create(attributes.getValue("importUri")));

        try {
            res.setProtocolInfo(
                    new ProtocolInfo(attributes.getValue("protocolInfo"))
            );
        } catch (InvalidValueException ex) {
            log.warning("In DIDL content, invalid resource protocol info: " + Exceptions.unwrap(ex));
            return null;
        }

        if (attributes.getValue("size") != null)
            res.setSize(Long.valueOf(attributes.getValue("size")));

        if (attributes.getValue("duration") != null)
            res.setDuration(attributes.getValue("duration"));

        if (attributes.getValue("bitrate") != null)
            res.setBitrate(Long.valueOf(attributes.getValue("bitrate")));

        if (attributes.getValue("sampleFrequency") != null)
            res.setSampleFrequency(Long.valueOf(attributes.getValue("sampleFrequency")));

        if (attributes.getValue("bitsPerSample") != null)
            res.setBitsPerSample(Long.valueOf(attributes.getValue("bitsPerSample")));

        if (attributes.getValue("nrAudioChannels") != null)
            res.setNrAudioChannels(Long.valueOf(attributes.getValue("nrAudioChannels")));

        if (attributes.getValue("colorDepth") != null)
            res.setColorDepth(Long.valueOf(attributes.getValue("colorDepth")));

        if (attributes.getValue("protection") != null)
            res.setProtection(attributes.getValue("protection"));

        if (attributes.getValue("resolution") != null)
            res.setResolution(attributes.getValue("resolution"));

        return res;
    }

    protected DescMeta createDescMeta(Attributes attributes) {
        DescMeta desc = new DescMeta();

        desc.setId(attributes.getValue("id"));

        if ((attributes.getValue("type") != null))
            desc.setType(attributes.getValue("type"));

        if ((attributes.getValue("nameSpace") != null))
            desc.setNameSpace(URI.create(attributes.getValue("nameSpace")));

        return desc;
    }


    /* ############################################################################################# */


    /**
     * Generates a XML representation of the content model.
     * <p>
     * Items inside a container will <em>not</em> be represented in the XML, the containers
     * will be rendered flat without children.
     * </p>
     *
     * @param content The content model.
     * @return An XML representation.
     * @throws Exception
     */
    public String generate(DIDLContent content) throws Exception {
        return generate(content, false);
    }

    /**
     * Generates an XML representation of the content model.
     * <p>
     * Optionally, items inside a container will be represented in the XML,
     * the container elements then have nested item elements. Although this
     * parser can read such a structure, it is unclear whether other DIDL
     * parsers should and actually do support this XML.
     * </p>
     *
     * @param content     The content model.
     * @param nestedItems <code>true</code> if nested item elements should be rendered for containers.
     * @return An XML representation.
     * @throws Exception
     */
    public String generate(DIDLContent content, boolean nestedItems) throws Exception {
        return documentToString(buildDOM(content, nestedItems), true);
    }

    // TODO: Yes, this only runs on Android 2.2

    protected String documentToString(Document document, boolean omitProlog) throws Exception {
        TransformerFactory transFactory = TransformerFactory.newInstance();

        // Indentation not supported on Android 2.2
        //transFactory.setAttribute("indent-number", 4);

        Transformer transformer = transFactory.newTransformer();

        if (omitProlog) {
            // TODO: UPNP VIOLATION: Terratec Noxon Webradio fails when DIDL content has a prolog
            // No XML prolog! This is allowed because it is UTF-8 encoded and required
            // because broken devices will stumble on SOAP messages that contain (even
            // encoded) XML prologs within a message body.
            transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        }

        // Again, Android 2.2 fails hard if you try this.
        //transformer.setOutputProperty(OutputKeys.INDENT, "yes");

        StringWriter out = new StringWriter();
        transformer.transform(new DOMSource(document), new StreamResult(out));
        return out.toString();
    }

    protected Document buildDOM(DIDLContent content, boolean nestedItems) throws Exception {

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);

        Document d = factory.newDocumentBuilder().newDocument();

        generateRoot(content, d, nestedItems);

        return d;
    }

    protected void generateRoot(DIDLContent content, Document descriptor, boolean nestedItems) {
        Element rootElement = descriptor.createElementNS(DIDLContent.NAMESPACE_URI, "DIDL-Lite");
        descriptor.appendChild(rootElement);

        // rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:didl", DIDLContent.NAMESPACE_URI);
        rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:upnp", DIDLObject.Property.UPNP.NAMESPACE.URI);
        rootElement.setAttributeNS("http://www.w3.org/2000/xmlns/", "xmlns:dc", DIDLObject.Property.DC.NAMESPACE.URI);

        for (Container container : content.getContainers()) {
            if (container == null) continue;
            generateContainer(container, descriptor, rootElement, nestedItems);
        }

        for (Item item : content.getItems()) {
            if (item == null) continue;
            generateItem(item, descriptor, rootElement);
        }

        for (DescMeta descMeta : content.getDescMetadata()) {
            if (descMeta == null) continue;
            generateDescMetadata(descMeta, descriptor, rootElement);
        }
    }

    protected void generateContainer(Container container, Document descriptor, Element parent, boolean nestedItems) {

        if (container.getTitle() == null) {
            throw new RuntimeException("Missing 'dc:title' element for container: " + container.getId());