dom4j写xml

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;

public   class  DOM4JTest  {

    /** */
    /** */
    /** */
    /**
     * DOM4J读写XML示例
     * 
     * @param args
     * @throws Exception
     */
    public static void 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();
        }

    }
}

执行结果应该是这样：



循环解析节点：

private   void  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();
        }
    }

     private   void  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);
        }
    }