import java.io.File;import java.io.FileWriter;import java.util.Iterator;import org.dom4j.Document;import org.dom4j.DocumentHelper;import org.dom4j.Element;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;
publicclass DOM4JTest { 
/***//***//***//** * DOM4J读写XML示例 * * @param args * @throws Exception
*/publicstaticvoid main(String[] args) { try{ XMLWriter writer =null;// 声明写XML的对象 SAXReader reader =new SAXReader(); OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding("GBK");// 设置XML文件的编码格式 String filePath ="d:\\student.xml"; File file =new File(filePath);if (file.exists()) { Document document = reader.read(file);// 读取XML文件 Element root = document.getRootElement();// 得到根节点boolean bl =false;for (Iterator i = root.elementIterator("学生"); i.hasNext();) { Element student = (Element) i.next();if (student.attributeValue("sid").equals("001")) { // 修改学生sid=001的学生信息 student.selectSingleNode("姓名").setText("王五"); student.selectSingleNode("年龄").setText("25"); writer =new XMLWriter(new FileWriter(filePath), format); writer.write(document); writer.close(); bl =true;break; } }if (bl) { // 添加一个学生信息 Element student = root.addElement("学生"); student.addAttribute("sid", "100"); Element sid = student.addElement("编号"); sid.setText("100"); Element name = student.addElement("姓名"); name.setText("嘎嘎"); Element sex = student.addElement("性别"); sex.setText("男"); Element age = student.addElement("年龄"); age.setText("21"); writer =new XMLWriter(new FileWriter(filePath), format); writer.write(document); writer.close(); } }else{ // 新建student.xml文件并新增内容 Document _document = DocumentHelper.createDocument(); Element _root = _document.addElement("学生信息"); Element _student = _root.addElement("学生"); _student.addAttribute("sid", "001"); Element _id = _student.addElement("编号"); _id.setText("001"); Element _name = _student.addElement("姓名"); _name.setText("灰机"); Element _age = _student.addElement("年龄"); _age.setText("18"); writer =new XMLWriter(new FileWriter(file), format); writer.write(_document); writer.close(); } System.out.println("操作结束! "); }catch (Exception e) { e.printStackTrace(); } }
} 
循环解析节点： privatevoid getAllNodes(String xml) { try{ Document authtmp = DocumentHelper.parseText(xml); List<Element> list = authtmp.selectNodes("//sms/node");for (int j =0; j < list.size(); j++) { Element node = (Element) list.get(j); nodeByNodes(node); } }catch (Exception e) { e.printStackTrace(); } }privatevoid nodeByNodes(Element node) { if (node.element("node") !=null) { String id = node.attributeValue("id"); String name = node.attributeValue("name"); System.out.print(id +"-------"); System.out.println(name);for (Iterator i = node.elementIterator("node"); i.hasNext();) { Element newNode = (Element) i.next(); nodeByNodes(newNode); } }else{ String id = node.attributeValue("id"); String name = node.attributeValue("name"); System.out.print(id +"-------"); System.out.println(name); } } 1.读取XML文件,获得document对象.
SAXReader reader = new SAXReader(); Document document = reader.read( new File( " input.xml " )); 2.解析XML形式的文本,得到document对象.
String text = " <members></members>"; Document document = DocumentHelper.parseText(text); 3.主动创建document对象.
Document document = DocumentHelper.createDocument(); Element root = document.addElement( " members " ); // 创建根节点 二.节点相关
1.获取文档的根节点.
Element rootElm = document.getRootElement(); 2.取得某节点的单个子节点.
Element memberElm = root.element( " member " ); // "member"是节点名 3.取得节点的文字
String text = memberElm.getText(); String text = root.elementText( " name " ); 4.取得某节点下名为"member"的所有字节点并进行遍历.
List nodes = rootElm.elements( " member"); for (Iterator it = nodes.iterator(); it.hasNext();) { Element elm = (Element) it.next(); // do something } 5.对某节点下的所有子节点进行遍历.
for (Iterator it = root.elementIterator();it.hasNext();) { Element element = (Element) it.next();// do something } 6.在某节点下添加子节点.
Element ageElm = newMemberElm.addElement( " age " ); 7.设置节点文字.
ageElm.setText( " 29 " ); 8.删除某节点.
parentElm.remove(childElm); // childElm是待删除的节点,parentElm是其父节点 9.添加一个CDATA节点.
Element contentElm = infoElm.addElement( " content " ); contentElm.addCDATA(diary.getContent()); contentElm.getText(); // 特别说明：获取节点的CDATA值与获取节点的值是一个方法 contentElm.clearContent(); //清除节点中的内容，CDATA亦可 三.属性相关.
1.取得某节点下的某属性
Element root = document.getRootElement(); Attribute attribute = root.attribute( " size " ); // 属性名name 2.取得属性的文字
String text = attribute.getText(); String text2 = root.element( " name " ).attributeValue( " firstname " ); 3.遍历某节点的所有属性
Element root = document.getRootElement(); for (Iterator it = root.attributeIterator();it.hasNext();) { Attribute attribute = (Attribute) it.next(); String text=attribute.getText(); System.out.println(text); } 4.设置某节点的属性和文字.
newMemberElm.addAttribute( " name " , " sitinspring " ); 5.设置属性的文字
Attribute attribute = root.attribute( " name " ); attribute.setText( " sitinspring " ); 6.删除某属性
Attribute attribute = root.attribute( " size " ); // 属性名name root.remove(attribute); 四.将文档写入XML文件. 1.文档中全为英文,不设置编码,直接写入的形式.
XMLWriter writer = new XMLWriter( new FileWriter( " output.xml " ));writer.write(document);writer.close(); 2.文档中含有中文,设置编码格式写入的形式.
OutputFormat format = OutputFormat.createPrettyPrint(); format.setEncoding( " GBK " ); // 指定XML编码 XMLWriter writer = new XMLWriter( new FileWriter( " output.xml " ),format); writer.write(document); writer.close(); 五.字符串与XML的转换
1.将字符串转化为XML
String text = " <members> <member>sitinspring</member> </members> " ;Document document = DocumentHelper.parseText(text); 2.将文档或节点的XML转化为字符串.
SAXReader reader = new SAXReader(); Document document = reader.read( new File( " input.xml " )); Element root = document.getRootElement(); String docXmlText = document.asXML(); String rootXmlText = root.asXML(); Element memberElm = root.element( " member " ); String memberXmlText = memberElm.asXML();