1. 建立一個簡單的例子，這個是別人寫的。其實我個人還是比較喜歡Json更加的簡單好使用
   

import java.io.File;
import java.io.FileOutputStream;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;


public class Demo {
 public static void main(String[] args) throws Exception {
  Document doc = DocumentHelper.createDocument
 
();
  //增加根節點
  Element books = doc.addElement("books");
  //增加子元素
  Element book1 = books.addElement("book");
  Element title1 = book1.addElement("title");
  Element author1 = book1.addElement("author");

  Element book2 = books.addElement("book");
  Element title2 = book2.addElement("title");
  Element author2 = book2.addElement
 
("author");

  //為子節點新增屬性
  book1.addAttribute("id", "001");
  //為元素新增內容
  title1.setText("Harry Potter");
  author1.setText("J K. Rowling");

  book2.addAttribute("id", "002");
  title2.setText("Learning XML");
  author2.setText("Erik T. Ray");

  //例項化輸出格式物件
  OutputFormat format = OutputFormat.createPrettyPrint
 
();
  //設定輸出編碼
  format.setEncoding("UTF-8");
  //建立需要寫入的File物件
  File file = new File("D:" + File.separator + "books.xml");
  //生成XMLWriter物件，建構函式中的引數為需要輸出的檔案流和格式
  XMLWriter writer = new XMLWriter(new FileOutputStream(file), format);
  //開始寫入，write方法中包含上面建立的Document物件
  writer.write(doc);
 }
}

其實這裡來說的話，我們可以看到。和html就是一個原理，屬性，text,增加子元素

通過反射進行操作，進行增加屬新元素

public static void writeAttributes(Element element, Object obj) {
        Class<?> cla = obj.getClass();
        Field[] fields = cla.getDeclaredFields();
        for(Field field : fields) {
            String name = field.getName();
            String getMethodName = "get"+toFirstLetterUpperCase(name);
            try {
                Object value = cla.getMethod(getMethodName).invoke(obj);
                element.addAttribute(name, value.toString());
            } catch (Exception e) {
            }
        }
    }