为什么StAX创建XML比DOM慢？

我试图测量StAX和DOM创建两个相同文档所需的时间。 我不知道为什么DOM在创建XML方面更快。 也许我的StAX编写器代码不是很好。 所以这里是StAX（更长的代码）

public static final int pocet =100000; try { String encoding = "UTF-8"; XMLOutputFactory f = XMLOutputFactory.newInstance(); XMLStreamWriter w = f.createXMLStreamWriter( new FileOutputStream(subor), encoding); w.writeStartDocument(encoding, "1.0"); w.writeCharacters("\r\n"); w.writeStartElement("Noviny"); for (int i = 1; i <= pocet; i++) { w.writeCharacters("\r\n "); w.writeStartElement("Autor"); w.writeCharacters("\r\n "); w.writeStartElement("Id"); String ID = Integer.toString(i); w.writeCharacters(ID); w.writeEndElement(); w.writeCharacters("\r\n "); w.writeStartElement("Meno"); w.writeCharacters("Autor"+i); w.writeEndElement(); w.writeCharacters("\r\n "); w.writeStartElement("Email"); w.writeCharacters("Autor"+i+"@email.com"); w.writeEndElement(); w.writeCharacters("\r\n "); w.writeStartElement("Tel_cislo"); w.writeAttribute("typ", "pevna"); w.writeCharacters("+4219"); w.writeEndElement(); w.writeCharacters("\r\n "); w.writeStartElement("plat"); w.writeCharacters("5000"); w.writeEndElement(); w.writeCharacters("\r\n "); w.writeEndElement(); w.writeCharacters("\r\n"); } w.writeCharacters("\r\n"); w.writeEndElement(); w.writeCharacters("\r\n"); w.writeEndDocument(); w.close(); } catch (Exception e) { e.printStackTrace(); } 

DOM

  int pocet =1500000; try { DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = dfactory.newDocumentBuilder(); DOMImplementation domImpl = builder.getDOMImplementation(); Document document = domImpl.createDocument(null, "Noviny", null); Node noviny = document.getDocumentElement(); for(int i = 0; i<pocet ; i++) { Element autor = document.createElement("autor"); Element meno = document.createElement("meno"); Element id = document.createElement("id"); Element email = document.createElement("email"); Element tel = document.createElement("tel_cislo"); Element plat = document.createElement("plat"); Text textid = document.createTextNode(""+i); Text textmeno = document.createTextNode("Autor"+i); Text textemail = document.createTextNode("[e-mail]"); Text texttel = document.createTextNode("65456465465"); Text textplat = document.createTextNode("200"); noviny.appendChild(autor); autor.appendChild(id); id.appendChild(textid); autor.appendChild(meno); meno.appendChild(textmeno); autor.appendChild(email); email.appendChild(textemail); autor.appendChild(tel); tel.appendChild(texttel); autor.appendChild(plat); plat.appendChild(textplat); } TransformerFactory factory = TransformerFactory.newInstance(); Transformer transformer = factory.newTransformer(); transformer.setOutputProperty(OutputKeys.INDENT, "yes"); transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); transformer.transform(new DOMSource(document),new StreamResult(new File(subor))); 

我知道StAX在阅读文档方面更快，但我无法解释这一点。 除了我有很糟糕的StAX代码

谢谢

Answer 1

在这里添加BufferedOuputStream

 XMLStreamWriter w = f.createXMLStreamWriter(new BufferedOutputStream(new FileOutputStream(subor)), "UTF-8"); 

现在测试速度，你会发现StAX的速度至少要快2倍