dom4j增删改查

    //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
    @Test
    public void add1() throws Exception{
        //读
        SAXReader reader = new SAXReader();
        Document document = reader.read(new File("src/book.xml"));

        //添加
        Element book = document.getRootElement().element("书");
        List list = book.elements();//[书名、作者、售价]
        Element price = DocumentHelper.createElement("售价");
        price.setText("309");    
        list.add(2,price);
        
        //输出
        OutputFormat format = OutputFormat.createPrettyPrint();
        format.setEncoding("UTF-8");
        XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
        writer.write(document);
        writer.close();

    }
    @Test
    public void deleat() throws Exception{
        //读
        SAXReader reader = new SAXReader();
        Document document = reader.read(new File("src/book.xml"));

        //删除
        Element price = document.getRootElement().element("书").element("售价");
        price.getParent().remove(price);
        
        //输出
        OutputFormat format = OutputFormat.createPrettyPrint();
        format.setEncoding("UTF-8");
        XMLWriter writer = new XMLWriter(new FileOutputStream("src/book.xml"),format);
        writer.write(document);
        writer.close();

    }