dom4j 解析xml

   对xml的解析，目前用的比较多的还是dom4j，古老的jdom可能还有人在用。不过，用vtd来解析xml速度和性能方面优势更为明显。下篇文章将会介绍。

  目前浅谈dom4j解析xml，dom4j是支持xpath的，这方便查找xml中的元素和值。枚举的方式实在有点bug，xml过于复杂的话，解析起来要写的代码就多了。

    import java.io.IOException;import java.io.InputStream;import java.io.StringWriter;import java.net.MalformedURLException;import java.util.Iterator;import java.util.List;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.Node;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;public class Test{// 将xml文件转化为Domcuemnt对象public Document read(String fileName) throws MalformedURLException, DocumentException{SAXReader reader = new SAXReader();Document document = reader.read(fileName);return document;}// 将xml文件转化为Document对象public Document parseToDocument(String fileName){SAXReader reader = new SAXReader();Document document = null;InputStream in = Test.class.getResourceAsStream(fileName);try{document = reader.read(in);}catch (DocumentException e){e.printStackTrace();System.out.println(e.getMessage());}return document;}// 获取根节点对象public Element getRootElement(Document document){return document.getRootElement();}// 遍历xml 枚举方式// 枚举的方式适合简单的xml 复杂的xml解析起来那是相当的耗时的@SuppressWarnings("unchecked")public void testParseXml(String fileName) throws MalformedURLException, DocumentException{Document document = read(fileName); // 获取document对象Element root = document.getRootElement(); // 获取根节点// 定义缓冲区StringBuffer buffer = new StringBuffer();buffer.append("第一个dom4j测试... /n");buffer.append("--------------start-----------------/n");for (Iterator iter = root.elementIterator(); iter.hasNext();){Element element = (Element) iter.next();String currentName = element.getName(); // 获取当前的名称String id = element.attributeValue("id");String sex = element.attributeValue("sex");String name = element.element("name").getText();String age = element.element("age").getText();buffer.append(currentName + ":/n");buffer.append("/tid=" + id + "sex=" + sex + "/n");buffer.append("/tname=" + name + "age=" + age + "/n");Element e_adds = element.element("adds");buffer.append(e_adds.getName() + ":/n");for (Iterator iters = e_adds.elementIterator(); iters.hasNext();){Element e_child = (Element) iters.next();String code = e_child.attributeValue("code");String add = e_child.getTextTrim();buffer.append("/t/t" + e_child.getName() + ":" + "code=" + code + " value=/"" + add + "/"/n");}buffer.append("/n");}buffer.append("--------------------end------------------------/n");System.out.println(buffer.toString());}// 遍历xml xpath方式@SuppressWarnings("unchecked")public void parseXmlXPath(String fileName) throws MalformedURLException, DocumentException{Document document = parseToDocument(fileName);//read(fileName); // 获取document对象System.out.println("xpath测试....");Node node1 = document.selectSingleNode("/doc/person");System.out.println("------node1---------" + node1.asXML());Node node2 = document.selectSingleNode("/doc/person/@sex");System.out.println("---------node2-------" + node2.asXML());Node node3 = document.selectSingleNode("/doc/person[name=/"zhangsan/"]/age");System.out.println("---------node3-----------" + node3.asXML());Node node4 = document.selectSingleNode("//age");System.out.println("----------node4---------------" + node4.asXML());Node node5 = document.selectSingleNode("doc"); // 获取所有 doc下的子节点System.out.println("----------node5---------------" + node5.asXML());Node node6 = document.selectSingleNode("/doc"); // 获取所有 doc下的子节点System.out.println("----------node6---------------" + node6.asXML());Node node7 = document.selectSingleNode("//name"); // 获取所有 doc下的子节点System.out.println("----------node7---------------" + node7.asXML());// 遍历xml中所有age属性 并获取其属性值List list = document.selectNodes("//age");for (Iterator it = list.iterator(); it.hasNext();){Node node = (Node) it.next();System.out.println("--------" + node.asXML() + "==========" + node.getText());}System.out.println("");}// 编码转换 可以对document的中文进行编码转换public String encodeXml(Document document, String encode){StringWriter sw = new StringWriter();OutputFormat format = OutputFormat.createPrettyPrint();format.setEncoding(encode);XMLWriter writer = new XMLWriter();writer.setWriter(sw);try{writer.write(document);}catch (IOException e){e.printStackTrace();}return sw.toString();}public static void main(String[] args) throws MalformedURLException, DocumentException{Test test = new Test();//test.read("personl.xml");test.parseXmlXPath("/personl.xml");}}

    因为有两种方式的写法，所以运行代码的时候要在项目根目录下和src下分别加personl.xml

   简要总结下：继续奋斗、、、