dom4j增删改查

 1     //dom4j添加内容，在第一本书上指定位置添加售价  更改保存所有孩子list集合的顺序
 2     @Test
 3     public void add1() throws Exception{
 4         //读
 5         SAXReader reader = new SAXReader();
 6         Document document = reader.read(new File("src/book.xml"));
 7 
 8         //添加
 9         Element book = document.getRootElement().element("书");
10         List list = book.elements();//[书名、作者、售价]
11         Element price = DocumentHelper.createElement("售价");
12         price.setText("309");    
13         list.add(2,price);
14         
15         //输出
16         OutputFormat format = OutputFormat.createPrettyPrint();
17         format.setEncoding("UTF-8");
18         XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
19         writer.write(document);
20         writer.close();
21 
22     }
23     @Test
24     public void deleat() throws Exception{
25         //读
26         SAXReader reader = new SAXReader();
27         Document document = reader.read(new File("src/book.xml"));
28 
29         //删除
30         Element price = document.getRootElement().element("书").element("售价");
31         price.getParent().remove(price);
32         
33         //输出
34         OutputFormat format = OutputFormat.createPrettyPrint();
35         format.setEncoding("UTF-8");
36         XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
37         writer.write(document);
38         writer.close();
39 
40     }