<?xml version="1.0" encoding="utf-8" standalone="no"?><书架> <书 name="xxxx"> <售价>109</售价> <书名>Java</书名> <作者>老张</作者> </书></书架>
@Test public void read() throws Exception{ //1.获取工厂 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book.xml")); NodeList list = document.getElementsByTagName("售价"); Node price = list.item(0); String value = price.getTextContent(); System.out.println(value); } //修改结点的值:<售价>39.00元</售价>改为109 @Test public void update() throws Exception{ DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book1.xml")); Node price = document.getElementsByTagName("售价").item(0); price.setTextContent("109"); //把内存中的document写到xml文档 TransformerFactory tf = TransformerFactory.newInstance(); //得到转换器 Transformer ts = tf.newTransformer(); ts.transform(new DOMSource(document), new StreamResult(new File("src/book1.xml"))); } //向指定节点中增加孩子节点（售价节点） @Test public void add() throws Exception{ DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book1.xml")); //创建需要增加的节点 Node price = document.createElement("售价"); price.setTextContent("59元"); //得到需要增加的节点的父亲 Node parent = document.getElementsByTagName("书").item(0); //把需要增加的节点挂到父结点上 parent.appendChild(price); TransformerFactory tf = TransformerFactory.newInstance(); Transformer ts = tf.newTransformer(); ts.transform(new DOMSource(document), new StreamResult(new File("src/book1.xml"))); } //向指定位置上插入售价节点 @Test public void add2() throws Exception{ DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book1.xml")); Node node = document.createElement("售价"); node.setTextContent("39元"); Node parent = document.getElementsByTagName("书").item(0); parent.insertBefore(node, document.getElementsByTagName("书名").item(0)); TransformerFactory tf = TransformerFactory.newInstance(); Transformer ts = tf.newTransformer(); ts.transform(new DOMSource(document), new StreamResult(new File("src/book1.xml"))); } //删除xml文档的售价结点 @Test public void delete() throws Exception{ DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book1.xml")); Node node = document.getElementsByTagName("售价").item(2); node.getParentNode().removeChild(node); TransformerFactory tf = TransformerFactory.newInstance(); Transformer ts = tf.newTransformer(); ts.transform(new DOMSource(document), new StreamResult(new File("src/book1.xml"))); } //操作xml文档属性 @Test public void updateAttribute() throws Exception{ DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Document document = builder.parse(new File("src/book1.xml")); //操作xml文档的元素时，一般都把元素当作node对象，但是程序员如果发现node不好使时，就应把node强转成相应类型 Node node = document.getElementsByTagName("书").item(0); Element book = null; if(node.getNodeType()==Node.ELEMENT_NODE){ //在作结点转换之前，最好先判断结点类型 book = (Element)node; } book.setAttribute("name", "yyyyyyy"); book.setAttribute("password", "123"); book.removeAttribute("password"); TransformerFactory tf = TransformerFactory.newInstance(); Transformer ts = tf.newTransformer(); ts.transform(new DOMSource(document), new StreamResult(new File("src/book1.xml"))); } //遍历 public static void list(Node node){ if(node.getNodeType()==Node.ELEMENT_NODE){ System.out.println(node.getNodeName()); } NodeList list = node.getChildNodes(); for(int i=0;i<list.getLength();i++){ Node child = list.item(i); list(child); } } 
