XML解析:
xml解析思想:
Document
Element
Text
Attribute
Comment
* SAX:逐行读取,基于事件驱动
* 优点:不占内存,速度快
* 缺点:只能读取,不能回写
xml常用的解析器:
1.导入jar包 dom4j.jar
2.创建解析器
SAXReader reader = new SAXReader();
3.解析xml 获得document对象
Document document = reader.read(url);
使用步骤:
1、注意:要导包 jaxen...jar
2、创建解析器
SAXReader reader = new SAXReader();
3、解析xml 获得document对象
Document document = reader.read(url);
* 解析XML:
// 1、得到某个具体的节点内容:第2本书的书名--》葵花宝典
// 2、遍历所有元素节点
XPath:
例子:
/* demo.xml <&#63;xml version="1.0" encoding="UTF-8"&#63;>*/ @Test public void test1() throws DocumentException{ SAXReader reader = new SAXReader(); Document doc = reader.read("./src/demo.xml"); Element root = doc.getRootElement(); Element book1 = root.element("book"); System.out.println(book1.getPath()); System.out.println(book1.elementText("price")); List<&#63;> list = root.elements("book"); Element book2 = (Element) list.get(1); System.out.println(book2.attributeValue("name")); for(Iterator<&#63;> it = book1.elementIterator();it.hasNext() ; ){ Element ele = (Element) it.next(); System.out.println(ele.getName()+" : "+ele.getText()); } } @Test public void test2() throws Exception{//使用 XPath,只用于快速查询,需要用jaxen...jar包 SAXReader reader = new SAXReader(); Document doc = reader.read(new File("src/demo.xml")); Node node = doc.selectSingleNode("/books/book[2]/author");//需要jaxen.jar包 String s = node.getText(); System.out.println(s); node = doc.selectSingleNode("/books/book[2]/@name"); s = node.getText(); System.out.println(s); List J.K. Rowling 29.90$ 马丁 28.90$ booknames = doc.selectNodes("/books//@name"); for (Node node1 : booknames) { System.out.println(node1.getText()); } List<&#63;> nodes = doc.selectNodes("/books/*/*"); for (int i=0; i
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