JDK原生类操作XML

使用JDK自带的类操作XML，包括从对象创建XML，并将XML转换为对象。

import java.io.ByteArrayInputStream;import java.io.StringWriter;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.transform.OutputKeys;import javax.xml.transform.Transformer;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;import org.w3c.dom.Node;/** * JDK 原生XML解析器封装 * @author lizhiyang * */public class XmlUtils {private static final String DEFAULT_ENCODING = "utf-8";/** ClientData有三个属性：ipAddress、port、source **/private static final String XML_ROOT = "root";private static final String XML_IPADDRESS = "ipAddress";private static final String XML_PORT = "port";private static final String XML_SOURCE = "source";/** * ClientData转换为XML格式字符串 * @param clientData * @return * @throws Exception */public static String convertClientData2XML(ClientData clientData) throws Exception {Document doc = null;DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();doc = builder.newDocument();//不进行校验doc.setXmlStandalone(true);//创建根节点jobcenterElement root = doc.createElement(XML_ROOT);doc.appendChild(root);//创建ipAddress节点Element ipAddress = doc.createElement(XML_IPADDRESS);Node ipAddressNode = doc.createTextNode(clientData.getIpAddress());ipAddress.appendChild(ipAddressNode);root.appendChild(ipAddress);//创建port节点Element port = doc.createElement(XML_PORT);Node portNode = doc.createTextNode(clientData.getPort());port.appendChild(portNode);root.appendChild(port);//创建source节点Element source = doc.createElement(XML_SOURCE);Node sourceNode = doc.createTextNode(clientData.getSource()+"");source.appendChild(sourceNode);root.appendChild(source);return document2String(doc);}/** * Document对象转换为字符串输出 * @param doc * @return * @throws Exception */private static String document2String(Document doc) throws Exception {TransformerFactory transFactory = TransformerFactory.newInstance();          Transformer transFormer = transFactory.newTransformer();          transFormer.setOutputProperty(OutputKeys.ENCODING, DEFAULT_ENCODING);          DOMSource domSource = new DOMSource(doc);          StringWriter sw = new StringWriter();          StreamResult xmlResult = new StreamResult(sw);          transFormer.transform(domSource, xmlResult);          return sw.toString();  }/** * XML格式字符串转换为ClientData对象 * @param xml * @return */public static ClientData convertXML2ClientData(String xml) throws Exception {ClientData clientData = null;ByteArrayInputStream bis = null;try {DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();bis = new ByteArrayInputStream(xml.getBytes(DEFAULT_ENCODING));Document doc = builder.parse(bis);String ipAddress = doc.getElementsByTagName(XML_IPADDRESS).item(0).getTextContent();String port = doc.getElementsByTagName(XML_PORT).item(0).getTextContent();String source = doc.getElementsByTagName(XML_SOURCE).item(0).getTextContent();clientData = new ClientData();clientData.setIpAddress(ipAddress);clientData.setPort(port);clientData.setSource(Integer.parseInt(source));} catch (Exception e) {throw e;} finally {if(bis != null) {bis.close();bis = null;}}return clientData;}public static void main(String[] args) {ClientData client = new ClientData();client.setIpAddress("1.2.3.4");client.setPort("100");client.setSource(1);try {String str = XmlUtils.convertClientData2XML(client);System.out.println(str);ClientData clientData = XmlUtils.convertXML2ClientData(str);System.out.println(clientData.getIpAddress()+" "+clientData.getPort()+" "+clientData.getSource());} catch (Exception e) {e.printStackTrace();}}}

以上只是非常简单的一个操作。如果对象不确定，此时我们可能就需要使用反射来获取属性了。当然了，这种方式也有很大的局限性。现在比较流行的dom4j等开源的第三方框架也有很多，都能够很方面的操作XML。这种方式只是为了在制作工具类的时候，如果不能引入第三方的工具类，使用JDK原生的类完全可以实现这些功能。