XML操作
一、使用Java读取XML文件
import java.io.File; import java.io.IOException; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.SAXException; public class ReadXML { public static void main(String[] args) { try { //DOM DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("languages.xml")); Element root = document.getDocumentElement(); System.out.println("cat="+root.getAttribute("cat")); NodeList list = root.getElementsByTagName("lan"); for (int i = 0; i < list.getLength(); i++) { Element lan = (Element) list.item(i); System.out.println("---------------"); System.out.println("id="+lan.getAttribute("id")); NodeList clist = lan.getChildNodes();
//注意这里的clist含有空白的回车和空格区 for (int j = 0; j < clist.getLength(); j++) { Node c = clist.item(j); if (c instanceof Element) { System.out.println(c.getNodeName()+"="+c.getTextContent()); } } } } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (SAXException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } }
二、使用Java创建XML
import java.io.File; import java.io.StringWriter; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.Transformer; import javax.xml.transform.TransformerConfigurationException; import javax.xml.transform.TransformerException; import javax.xml.transform.TransformerFactory; import javax.xml.transform.dom.DOMSource; import javax.xml.transform.stream.StreamResult; import org.w3c.dom.Document; import org.w3c.dom.Element; public class CreatXML { public static void main(String[] args) { try { //DOM DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.newDocument(); Element root = document.createElement("Languages"); root.setAttribute("cat", "it"); Element lan1 = document.createElement("lan"); lan1.setAttribute("id", "1"); Element name1 = document.createElement("name"); name1.setTextContent("Java"); Element ide1 = document.createElement("ide"); ide1.setTextContent("Eclipse"); lan1.appendChild(name1); lan1.appendChild(ide1); Element lan2 = document.createElement("lan"); lan2.setAttribute("id", "2"); Element name2 = document.createElement("name"); name2.setTextContent("Swift"); Element ide2 = document.createElement("ide"); ide2.setTextContent("XCode"); lan2.appendChild(name2); lan2.appendChild(ide2); Element lan3 = document.createElement("lan"); lan3.setAttribute("id", "3"); Element name3 = document.createElement("name"); name3.setTextContent("C#"); Element ide3 = document.createElement("ide"); ide3.setTextContent("Visual Studio"); lan3.appendChild(name3); lan3.appendChild(ide3); root.appendChild(lan1); root.appendChild(lan2); root.appendChild(lan3); document.appendChild(root); //------------- TransformerFactory transformerFactory = TransformerFactory.newInstance(); Transformer transformer = transformerFactory.newTransformer(); transformer.setOutputProperty("encoding", "UTF-8"); StringWriter writer = new StringWriter(); transformer.transform(new DOMSource(document), new StreamResult(writer)); System.out.println(writer.toString()); transformer.transform(new DOMSource(document), new StreamResult(new File("newxml.xml"))); } catch (ParserConfigurationException e) { e.printStackTrace(); } catch (TransformerConfigurationException e) { e.printStackTrace(); } catch (TransformerException e) { e.printStackTrace(); } } }
三、使用dom4j工具类库操作XML (www.dom4j.org)
import org.dom4j.Document; import org.dom4j.DocumentException; import org.dom4j.DocumentHelper; public class Test { public static void main(String[] args) { String xmlString = "<root><people>ACELY</people></root>"; try { Document document = DocumentHelper.parseText(xmlString); System.out.println(document.asXML()); } catch (DocumentException e) { e.printStackTrace(); } } }
学习技术不是用来写HelloWorld和Demo的,而是要用来解决线上系统的真实问题的.