registryio.java

FMJ（freedom media for java)是java视频开发的新选择

package net.sf.fmj.utility;

import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import java.util.logging.Logger;

import javax.media.CaptureDeviceInfo;
import javax.media.MediaLocator;
import javax.media.PlugInManager;

import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;

/**
 * 
 * @author Ken Larson
 * @author Warren Bloomer
 *
 */
public class RegistryIO
{
	private static final Logger logger = LoggerSingleton.logger;

	private final RegistryContents registryContents;
	
	/** version of the registry file format */
	private static final String version = "0.1";
	

	public RegistryIO(RegistryContents registryContents)
	{
		super();
		this.registryContents = registryContents;
	}	
	
	
	/* ---------------------- XML operations --------------------- */

	private static final String ELEMENT_REGISTRY = "registry";
	private static final String ATTR_VERSION = "version";
	
	private static final String ELEMENT_PROTO_PREFIX = "protocol-prefixes";
	private static final String ELEMENT_CONTENT_PREFIX = "content-prefixes";	
	private static final String ELEMENT_PLUGINS = "plugins";
	private static final String ELEMENT_MIMETYPES = "mime-types";
	private static final String ELEMENT_MIMETYPE = "type";
	private static final String ELEMENT_CAPTURE_DEVICES = "capture-devices";
	
	private static final String ELEMENT_CODECS = "codecs";
	private static final String ELEMENT_DEMUXES = "demuxes";
	private static final String ELEMENT_MUXES = "muxes";
	private static final String ELEMENT_EFFECTS = "effects";
	private static final String ELEMENT_RENDERERS = "renderers";
	
	private static final String ELEMENT_PREFIX = "prefix";
	private static final String ELEMENT_CLASS = "class";
	
	private static final String ELEMENT_DEVICE = "device";
	private static final String ELEMENT_DEVICE_NAME = "name";
	private static final String ELEMENT_DEVICE_LOCATOR = "locator";
	private static final String ELEMENT_DEVICE_FORMAT = "format";
	private static final String ELEMENT_DEVICE_FORMAT_CLASS = "class";
	private static final String ELEMENT_DEVICE_FORMAT_DESCRIPTION = "description";
	private static final String ELEMENT_DEVICE_FORMAT_SERIALIZED = "serialized";	
	/**
	 * Load the Registry data from a Reader/
	 */
	public void load(Reader reader) throws IOException {
		
		// read the registry
		try {
			SAXBuilder saxBuilder = new SAXBuilder();
			Document document = saxBuilder.build(reader);
			
			// read all the data from the document and place into data structures.
			loadDocument(document);
		}
		catch (JDOMException e) {
			// problem parsing XML.
			throw new IOException(e.getMessage());
		}
	}
	
	/**
	 * Write the registry data to the Writer.
	 * 
	 * @param writer destination for the registry data.
	 * @throws IOException
	 */
	public void write(Writer writer) throws IOException {
		// build document from registry data structures
		Document document = buildDocument();
		
		XMLOutputter xmlOutputter = new XMLOutputter();
		xmlOutputter.setFormat(Format.getPrettyFormat());

		xmlOutputter.output(document, writer);
	}
	

	private void loadDocument(Document document) throws IOException {
		
		Element rootElement = document.getRootElement();
		String versionString = rootElement.getAttributeValue(ATTR_VERSION);
		
		// TODO use version String
		logger.info("FMJ registry document version " + versionString);
		
		Element pluginsElement = rootElement.getChild(ELEMENT_PLUGINS);
		loadPlugins(pluginsElement);
		
		Element contentPrefixesElement = rootElement.getChild(ELEMENT_CONTENT_PREFIX);
		loadContentPrefixes(contentPrefixesElement);
		
		Element protocolPrefixesElement = rootElement.getChild(ELEMENT_PROTO_PREFIX);
		loadProtocolPrefixes(protocolPrefixesElement);
		
		Element mimetypesElement = rootElement.getChild(ELEMENT_MIMETYPES);
		loadMimeTypes(mimetypesElement);
		
		// load capture devices
		Element captureDevicesElement = rootElement.getChild(ELEMENT_CAPTURE_DEVICES);
		try {
			loadCaptureDevices(captureDevicesElement);
		} catch (ClassNotFoundException e) {
			throw new IOException(e.getMessage());
		}

	}
	
	private void loadPlugins(Element element) {
		
		Element codecsElement = element.getChild(ELEMENT_CODECS);
		loadPlugins(codecsElement, PlugInManager.CODEC);
		
		Element effectsElement = element.getChild(ELEMENT_EFFECTS);
		loadPlugins(effectsElement, PlugInManager.EFFECT);
		
		Element renderersElement = element.getChild(ELEMENT_RENDERERS);
		loadPlugins(renderersElement, PlugInManager.RENDERER);
		
		Element muxesElement = element.getChild(ELEMENT_MUXES);
		loadPlugins(muxesElement, PlugInManager.MULTIPLEXER);
		
		Element demuxesElement = element.getChild(ELEMENT_DEMUXES);
		loadPlugins(demuxesElement, PlugInManager.DEMULTIPLEXER);
	}
	
	/**
	 * 
	 * @param type
	 */
	private void loadPlugins(Element element, int type) {
		if (element == null) {
			return;
		}

		Vector vector = registryContents.plugins[type-1];
		List pluginElements = element.getChildren(ELEMENT_CLASS);
		for (int i=0; i<pluginElements.size(); i++) {
			Element pluginElement = (Element) pluginElements.get(i);
			String classname = pluginElement.getTextTrim();
			vector.add(classname);
		}
	}
	
	private void loadProtocolPrefixes(Element element) {
		registryContents.protocolPrefixList.clear();
		List list = element.getChildren(ELEMENT_PREFIX);
		for (int i=0; i<list.size(); i++) {
			Element prefixElement = (Element) list.get(i);
			registryContents.protocolPrefixList.add(prefixElement.getTextTrim());
		}
	}

	private void loadContentPrefixes(Element element) {
		registryContents.contentPrefixList.clear();
		List list = element.getChildren(ELEMENT_PREFIX);
		for (int i=0; i<list.size(); i++) {
			Element prefixElement = (Element) list.get(i);
			registryContents.contentPrefixList.add(prefixElement.getTextTrim());
		}
	}
	


	/**
	 * Builds a Document from the registry data structures.
	 * 
	 * @return the Document.
	 * @throws IOException 
	 */
	private Document buildDocument() throws IOException {
		Document document = new Document();
		
		Element rootElement = new Element(ELEMENT_REGISTRY);
		rootElement.setAttribute(ATTR_VERSION, version);
		
		document.setRootElement(rootElement);

		rootElement.addContent(getPluginsElement());
		rootElement.addContent(getContentElement());
		rootElement.addContent(getProtocolElement());
		rootElement.addContent(getMimeElement());
		rootElement.addContent(getCaptureDeviceElement());
		
		return document;
	}
	
	private Element getPluginsElement() {
		Element pluginElement = new Element(ELEMENT_PLUGINS);
		
		pluginElement.addContent(getCodecElement());
		pluginElement.addContent(getDemuxElement());
		pluginElement.addContent(getEffectElement());
		pluginElement.addContent(getMuxElement());
		pluginElement.addContent(getRendererElement());
		
		return pluginElement;
	}
	
	private Element getCodecElement() {
		return getPluginElement(PlugInManager.CODEC, ELEMENT_CODECS);
	}
	
	private Element getDemuxElement() {
		return getPluginElement(PlugInManager.DEMULTIPLEXER, ELEMENT_DEMUXES);
	}
	
	private Element getEffectElement() {
		return getPluginElement(PlugInManager.EFFECT, ELEMENT_EFFECTS);
	}
	
	private Element getMuxElement() {
		return getPluginElement(PlugInManager.MULTIPLEXER, ELEMENT_MUXES);
	}
	
	private Element getRendererElement() {
		return getPluginElement(PlugInManager.RENDERER, ELEMENT_RENDERERS);
	}
	
	private Element getPluginElement(int pluginType, String typeName) {
		Element pluginsElement = new Element(typeName);
		Vector plugins = registryContents.plugins[pluginType-1];
		
		if (plugins != null) {
			Iterator pluginIter = plugins.iterator();
			while (pluginIter.hasNext()) {
				String classname = (String) pluginIter.next();
				Element pluginElement = new Element(ELEMENT_CLASS);
				pluginElement.setText(classname);	
				
				pluginsElement.addContent(pluginElement);
			}
		}
		
		return pluginsElement;
	}
	
	private Element getContentElement() {
		Element contentElement = new Element(ELEMENT_CONTENT_PREFIX);
		
		Iterator prefixIter = registryContents.contentPrefixList.iterator();
		while (prefixIter.hasNext()) {
			String prefix = (String) prefixIter.next();
			Element prefixElement = new Element(ELEMENT_PREFIX);
			prefixElement.setText(prefix);
			contentElement.addContent(prefixElement);
		}

		return contentElement;
	}
	
	private Element getProtocolElement() {
		Element protocolElement = new Element(ELEMENT_PROTO_PREFIX);
		Iterator prefixIter = registryContents.protocolPrefixList.iterator();
		while (prefixIter.hasNext()) {
			String prefix = (String) prefixIter.next();
			Element prefixElement = new Element(ELEMENT_PREFIX);
			prefixElement.setText(prefix);
			protocolElement.addContent(prefixElement);
		}
		return protocolElement;
	}

	/* -------------- MIME methods -------------- */
	

	private void loadMimeTypes(Element element)
	{
		registryContents.mimeTable.clear();
		
		final List list = element.getChildren(ELEMENT_MIMETYPE);
		for (int i=0; i<list.size(); i++) {
			final Element typeElement = (Element) list.get(i);
			String type = typeElement.getAttributeValue("value");
			String defaultExtension = typeElement.getAttributeValue("default-ext");
			
			final List list2 = typeElement.getChildren("ext");
			for (int j=0; j<list2.size(); j++) {
				final Element extElement = (Element) list2.get(j);
				String ext = extElement.getText();
				
				registryContents.mimeTable.addMimeType(ext, type);
			}
			registryContents.mimeTable.addMimeType(defaultExtension, type);
		}
	}
	
	private Element getMimeElement() {
		Element mimeElement = new Element(ELEMENT_MIMETYPES);
		
		final Iterator typesIterator = registryContents.mimeTable.getMimeTypes().iterator();
		while (typesIterator.hasNext())
		{
			final String type = (String) typesIterator.next();
			final List extensions = registryContents.mimeTable.getExtensions(type);
			
			final Element typeElement = new Element(ELEMENT_MIMETYPE);
			typeElement.setAttribute("value", type);
			typeElement.setAttribute("default-ext", registryContents.mimeTable.getDefaultExtension(type));
			mimeElement.addContent(typeElement);
			
			for (int i = 0; i < extensions.size(); ++i)
			{
				String ext = (String) extensions.get(i);
				final Element extElement = new Element("ext");
				extElement.setText(ext);
				typeElement.addContent(extElement);
			}
			
		}
		
		return mimeElement;
	}
	
	/* -------------- Capture Device methods -------------- */

	private void loadCaptureDevices(Element element) throws IOException, ClassNotFoundException {
		registryContents.captureDeviceInfoList.clear();
		final List list = element.getChildren(ELEMENT_DEVICE);
		for (int i=0; i<list.size(); i++) {
			final Element deviceElement = (Element) list.get(i);
			final Element deviceNameElement = deviceElement.getChild(ELEMENT_DEVICE_NAME);
			final Element deviceLocatorElement = deviceElement.getChild(ELEMENT_DEVICE_LOCATOR);
			final List formatElementsList = deviceElement.getChildren(ELEMENT_DEVICE_FORMAT);
			final javax.media.Format[] formats = new javax.media.Format[formatElementsList.size()];
			for (int j = 0; j < formatElementsList.size(); ++j) {
				final Element formatElement = (Element) formatElementsList.get(j);
				final Element serializedElement = formatElement.getChild(ELEMENT_DEVICE_FORMAT_SERIALIZED);
				formats[j] = SerializationUtils.deserialize(serializedElement.getTextTrim());
			}
			
			final CaptureDeviceInfo info = new CaptureDeviceInfo(deviceNameElement.getTextTrim(), new MediaLocator(deviceLocatorElement.getTextTrim()), formats);
			registryContents.captureDeviceInfoList.add(info);
			
		}
	}

	private Element getCaptureDeviceElement() throws IOException {
		final Element captureDeviceElement = new Element(ELEMENT_CAPTURE_DEVICES);
		final Iterator<CaptureDeviceInfo> iter = registryContents.captureDeviceInfoList.iterator();
		while (iter.hasNext()) {
			final CaptureDeviceInfo info = iter.next();
			
			if (info.getLocator() == null)	
				continue; // should never be null, only seems to be null due to some unit tests.
			
			final Element deviceElement = new Element(ELEMENT_DEVICE);
			{
				final Element deviceNameElement = new Element(ELEMENT_DEVICE_NAME);
				deviceNameElement.setText(info.getName());
				deviceElement.addContent(deviceNameElement);
			}
			
			{
				final Element e = new Element(ELEMENT_DEVICE_LOCATOR);
				e.setText(info.getLocator().toExternalForm());
				deviceElement.addContent(e);
			}
			{
				final javax.media.Format[] formats = info.getFormats();
				for (int i = 0; i < formats.length; ++i)
				{
					final Element formatElement = new Element(ELEMENT_DEVICE_FORMAT);
					
					{
						final Element e2 = new Element(ELEMENT_DEVICE_FORMAT_CLASS); // for XML readability only
						e2.setText(formats[i].getClass().getName());
						formatElement.addContent(e2);
					}
					
					{
						final Element e2 = new Element(ELEMENT_DEVICE_FORMAT_DESCRIPTION); // for XML readability only
						e2.setText(formats[i].toString());
						formatElement.addContent(e2);
					}
					// TODO: perhaps "known" formats like RGBFormat could be serialized much more nicely.
					// we have to use serialization because that is the only way to support JMF-compatible subclasses
					// that are not in JMF.
					{
						final Element e2 = new Element(ELEMENT_DEVICE_FORMAT_SERIALIZED);
						e2.setText(SerializationUtils.serialize(formats[i]));
						formatElement.addContent(e2);
					}
					
					deviceElement.addContent(formatElement);
				}
			}
		

			captureDeviceElement.addContent(deviceElement);
		}
		return captureDeviceElement;
	}



}