xml(3）

xml的解析方式：dom解析和sax解析

DOM解析

使用jaxp进行增删改查

1.创建DocumentBuilderFactory工厂

2.通过DocumentBuilderFactory工厂创建DocumentBuilder

3.解析xml，得到Document对象

*在对document进行增删改查操作时，需要回写到xml中：

1.创建TransformerFactory回写工厂

2.通过回写工厂，获得Transformer

3.Transformer.transform(new DOMSource(document),new StreamResult(""))

查

 private static void selectALL() throws Exception {
     /**
      *
      * 1.创建DocumentFacTory工厂
      * 2.通过Document Factory工厂得到DocumentBuilder
      * 3.解析xml得到Document对象
      */

     //创建工厂
     DocumentBuilderFactory documentBuilderFactory=DocumentBuilderFactory.newInstance();
     //创建BUilder
     DocumentBuilder documentBuilder=documentBuilderFactory.newDocumentBuilder();
     //解析xml 获得document对象
     Document document=documentBuilder.parse("src/com//zyf/test.xml");

     //获得所有name元素
     NodeList list=document.getElementsByTagName("sex");
     //遍历
     for(int i=0;i<list.getLength();i++){
         Node node1=list.item(i);
         System.out.println(node1.getTextContent());
     }
 }

 

增

public static void addSex() throws Exception{
    //创建工厂
    DocumentBuilderFactory documentBuilderFactory=DocumentBuilderFactory.newInstance();
    //获得builder
    DocumentBuilder documentBuilder=documentBuilderFactory.newDocumentBuilder();
    //获得deocument
    Document document=documentBuilder.parse("src/com/zyf/test.xml");
    //创建节点<sex>nv</sex>
    Node sex=document.createElement("sex");
    //在sex中创建文本
    Node text=document.createTextNode("nv");
//    sex.setTextContent("nv");
    sex.appendChild(text);
    //得到sex的父节点<p1>
    NodeList list=document.getElementsByTagName("p1");
    Node node1=list.item(0);
    //添加进父节点p1
    node1.appendChild(sex);

    //回写
    TransformerFactory transformerFactory=TransformerFactory.newInstance();
    Transformer transformer=transformerFactory.newTransformer();
    transformer.transform(new DOMSource(document),new StreamResult("src/com/zyf/test.xml"));
}

删

public static void removeSex()throws Exception{
    //创建工厂
    DocumentBuilderFactory documentBuilderFactory=DocumentBuilderFactory.newInstance();
    //闯将builder
    DocumentBuilder documentBuilder=documentBuilderFactory.newDocumentBuilder();
    //获得document
    Document document=documentBuilder.parse("src/com/zyf/test.xml");
    //获得sex的父节点
    //获得sex
    NodeList list=document.getElementsByTagName("sex");
    Node node1=list.item(0);
    //获得sex的父节点
    Node parent=node1.getParentNode();
    //remove
    parent.removeChild(node1);
    //回写
    //回写工厂
    TransformerFactory transformerFactory=TransformerFactory.newInstance();
    Transformer transformer=transformerFactory.newTransformer();
    transformer.transform(new DOMSource(document), new StreamResult("src/com/zyf/test.xml"));
}[Document是Node的子类]

 xml的sax解析方式