解析xml文件时未知的主机异常

我用下面的代码，这对我来说很好。

documentBuilderFactory dbf = documentBuilderFactory.newInstance();  dbf.setValidating(false);documentBuilder db = dbf.newdocumentBuilder();db.setEntityResolver(new EntityResolver() {  @Override  public InputSource resolveEntity(String arg0, String arg1)        throws SAXException, IOException {    if(arg0.contains("Hibernate")) {        return new InputSource(new StringReader(""));    } else {        // TODO Auto-generated method stub        return null;    }  }});document doc = db.parse(hbmFile);