private static Document getConfigDocument() throws ReaderConfigException {
//拼出配置文件的路径		
		String configFilePath = System.getProperty("user.dir") + System.getProperty("file.separator") + "SourceSwitcher.xml";
		try {
			if (!new File(configFilePath).exists())
				throw new ReaderConfigException("File \"SourceSwitcher.xml\" not found!");
			DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
			Document doc = docBuilder.parse(configFilePath);
			return doc;
		} catch (ParserConfigurationException e) {
			throw new ReaderConfigException(e);
		} catch (SAXException e) {
			throw new ReaderConfigException(e);
		} catch (IOException e) {
			throw new ReaderConfigException(e);
		}
	}