TransformerFactory.newInstance()停止?

我编写了在打印之前将文档转换为字符串的代码

        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer trans = tf.newTransformer();
        trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        trans.setOutputProperty(OutputKeys.INDENT, "yes");


        //create string from xml tree
        StringWriter sw = new StringWriter();
        StreamResult result = new StreamResult(sw);
        DOMSource source = new DOMSource(doc);
        trans.transform(source, result);
        xmlString = sw.toString();

这在一个独立的程序中非常有效。我已将此代码直接剪切并粘贴到运行在jakarta-tomcat-5.0.28(jdk1.5)下的模块中,它在TransformerFactory.newInstance(). 我需要告诉jakarta下的jvm什么地方可以找到合适的类吗?顺便说一句,电话再也没有回过,只是停止了,没有回应。