使用StAX剪切xml部件并使用XSLT处理它们

Question

我试图将xml剪切成部分，然后应用它进行一些转换。目前我有这段代码：

    public class XMLStax_xslt {

        static boolean allowStream = false;

        public static void main(String[] args) throws Exception {
            FileInputStream fis = new FileInputStream("SourceExternalFile.xml");        
            XMLInputFactory xmlif = null;
            xmlif = XMLInputFactory.newInstance();
            Source xslt = new StreamSource(new File("myTransformFile.xslt"));

            StreamFilter filter = new StreamFilter() {
                @Override
                public boolean accept(XMLStreamReader reader) {
                    int eventType = reader.getEventType();

                    if ( eventType == XMLEvent.START_ELEMENT )
                    {
                        String currentTag = reader.getLocalName();
                        if (currentTag.equals("wantedTag"))
                        {
                            allowStream = true;
                        }
                    }
                    if ( eventType == XMLEvent.END_ELEMENT )
                    {
                        String currentTag = reader.getLocalName();
                        if (currentTag.equals("wantedTag"))
                        {
                            allowStream = false;
                        }
                    }               
                    return allowStream;
                }
            };
            XMLStreamReader xmlR = xmlif.createFilteredReader(xmlif.createXMLStreamReader(fis),filter);
            while (xmlR.hasNext())
            {
                TransformerFactory transformerXSLT = TransformerFactory.newInstance();
                Transformer currentXslt = transformerXSLT.newTransformer(xslt);
                currentXslt.transform(new StAXSource(xmlR), new StreamResult("targetFile.xml"));
            }        
            fis.close();
        }   
    }

当行return allowStream;更改为return true;时，哪个有效。所以，我需要的只是发送我需要的部分进行转换，因为发送整个XML不是一个选项。

我怎样才能做到这一点？

感谢。

Answer 1

麻烦的是我将字符串传递给变换器，而不是整个节点。将XMLStreamReader改为XMLEventReader可以解决问题。

这是改变：

    public static void main(String[] args) throws Exception {
            FileInputStream fis = new FileInputStream("SourceExternalFile.xml");        
            XMLInputFactory xmlif = null;
            xmlif = XMLInputFactory.newInstance();
            Source xslt = new StreamSource(new File("myTransformFile.xslt"));

            XMLEventReader xmlR = xmlif.createXMLEventReader(xmlif.createXMLStreamReader(fis));

            TransformerFactory transformerXSLT = TransformerFactory.newInstance();
            Transformer currentXslt = transformerXSLT.newTransformer(xslt);

            while (xmlR.hasNext())
            {
                XMLEvent xmlEvent = xmlR.nextEvent();
                if ( xmlEvent.equals("wantedTag") )
                {
                    currentXslt.transform(new StAXSource(xmlR), new StreamResult("targetFile.xml"));
                }
            }
            xmlR.close();
            fis.close();
        }