Java：如何防止EntityResolver中的’systemId’#resolveEntity(S

<!DOCTYPE doc SYSTEM 'mydoc.dtd'>
 <doc>&title;</doc>

我的EntityResolver应该从数据库中获取具有给定系统ID的外部实体,然后执行解决方案,请参阅下面的插图：

private static class MyEntityResolver
 {
    public InputSource resolveEntity(String publicId,String systemId)
        throws SAXException,IOException
    {
        // At this point,systemId is always absolutized to the current working directory,// even though the XML document specified it as relative.
        // E.g. "file:///H:/mydoc.dtd" instead of just "mydoc.dtd"
        // Why???  How can I prevent this???

        SgmlEntity entity = findEntityFromDatabase(systemId);
        InputSource is = new InputSource(new ByteArrayInputStream(entity.getContents()));
        is.setPublicId(publicId);
        is.setSystemId(systemId);
        return is;
    }
 }

我尝试使用DOM(DocumentBuilder)和SAX(XMLReader),将实体解析器设置为MyEntityResolver(即setEntityResolver(new MyEntityResolver())),但MyEntityResolver中的systemId #resolveEntity(String publicId,String systemId)始终被绝对化为当前的工作目录.

我也尝试过调用setFeature(“http://xml.org/sax/features/resolve-dtd-uris”,false);但这对任何事都没有帮助.

那么我怎样才能达到我的目的呢？

谢谢！