XML种文件和监听方法

XML类文件和监听方法
public class XMLFileListener extends FileListener
{
    private Logger logger = Logger.getLogger(FileListener.class);
      private EnumerateFile enumerateFile;
    XMLFileListener(String filePath)
    {
        if (filePath != null)
        {
            this.file = new File(filePath);
            if (!file.isFile())
            {
                logger.error("The file[" + filePath
                        + "] doesn't exist, please check it.");
                return;
            }
            enumerateFile = new EnumerateFile(filePath);
        }
    }
    public boolean isFileUpdated()
    {
        return enumerateFile.getEnumFile().lastModified() > enumerateFile
                .getEnumLastModifieds();
    }
    public void loadFile()
    {
        loadXml();
    }
    public String getPropertyValue(String key)
    {
        return getTransferValue(key);
    }
    private void loadXml()
    {
        // 更新时间
        enumerateFile.setEnumLastModifieds(enumerateFile.getEnumFile()
                .lastModified());
        // 解析XML
        Element rootElement = XMLParserHelperDom4j.parserXML(enumerateFile
                .getEnumFile().getPath());
        if (rootElement == null)
        {
            logger.error("The file[" + enumerateFile.getEnumFile().getPath()
                    + "] parser error,please check again.");
        }
        else
        {
            // 将解析的文档的根节点保存，供以后读取所用
            enumerateFile.setEnumElement(rootElement);
            // logger.info("The file load:" + xmlBuf.toString());
            logger.info("The properties file["
                    + enumerateFile.getEnumFile().getPath()
                    + "] load complete.");
        }
    }
    public String getTransferValue(String key)
    {
        // 由 Type + OriginallyValue + value 或 Type + TransferAttr + value组成。
        String[] keys = key.split("\\|\\|");
        // 没有传Value 是返回null
        if (keys.length == 2)
            return null;
        String transferValue = keys[2];
        Element transferAttrs = XMLParserHelperDom4j.getElement(
                enumerateFile.getEnumElement(), null, keys[0]);
        if (transferAttrs == null)
        {
            return null;
        }
        for (Iterator<?> i = transferAttrs.elementIterator(); i.hasNext();)
        {
            Element transfer = (Element) i.next();

            if (transfer == null)
                continue;

            String orig_str = XMLParserHelperDom4j.getText(transfer,
                    XMLParserHelperDom4j.ORIGINALL_VALUE);
            String tran_str = XMLParserHelperDom4j.getText(transfer,
                    XMLParserHelperDom4j.TRANSFER_VALUE);

            if (XMLParserHelperDom4j.ORIGINALL_VALUE.equals(keys[1])
                    && keys[2].equals(orig_str))
            {
                transferValue = tran_str;
                return transferValue;
            }
            else if (XMLParserHelperDom4j.TRANSFER_VALUE.equals(keys[1])
                    && keys[2].equals(tran_str))
            {
                transferValue = orig_str;
                return transferValue;
            }
        }
        logger.warn("Cannot found the value [" + keys[2] + "] by node["
                + keys[0] + " in xml file]");
        return transferValue;
    }
}