1 //使用 jaxp 对xml文档进行dom解析 2 public class Demo2 { 3 4 //必要步骤 5 @Test 6 public void test() throws Exception { 7 8 //1.创建工厂 9 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 10 11 //2.得到dom解析器 12 DocumentBuilder db = dbf.newDocumentBuilder(); 13 14 //3.解析XML文档，得到代表文档的Document 15 Document d = db.parse("src/com/xml/javaweb/book.xml"); 16 17 18 } 19 }
示例：对xml节点进行增删改查
1 public class Demo3 { 2 //读取XML文件中：<书名>javaWEB</书名> 节点中的值 3 @Test 4 public void read() throws Exception { 5 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 6 DocumentBuilder db = dbf.newDocumentBuilder(); 7 Document d = db.parse("src/com/xml/javaweb/book.xml"); 8 9 NodeList list = d.getElementsByTagName("书名"); 10 Node node = list.item(1); 11 String text = node.getTextContent(); 12 System.out.println(text); 13 } 14 15 //遍历整个XML文档中的节点 16 @Test 17 public void read1() throws Exception { 18 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 19 DocumentBuilder db = dbf.newDocumentBuilder(); 20 Document d = db.parse("src/com/xml/javaweb/book.xml"); 21 22 //得到根节点 23 NodeList list = d.getElementsByTagName("书架"); 24 Node root = list.item(0); 25 list(root); 26 } 27 28 private void list(Node root) { 29 if(root instanceof Element) 30 System.out.println(root.getNodeName()); 31 32 NodeList nodelist = root.getChildNodes(); 33 for(int i = 0;i<nodelist.getLength();i++) { 34 Node node = nodelist.item(i); 35 list(node); 36 } 37 } 38 39 //拿到 name 属性的值 40 @Test 41 public void read2() throws Exception { 42 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 43 DocumentBuilder db = dbf.newDocumentBuilder(); 44 Document d = db.parse("src/com/xml/javaweb/book.xml"); 45 46 Element node = (Element) d.getElementsByTagName("书名").item(0); //node 里面的方法不够用了 没有指定名字得到属性，在知道得到的是Element的情况下 ，把node强转一下 47 String att = node.getAttribute("name"); 48 System.out.println(att); 49 } 50 51 //向XML文档中添加节点 <售价>39.00元</售价> 52 @Test 53 public void add() throws Exception { 54 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 55 DocumentBuilder db = dbf.newDocumentBuilder(); 56 Document d = db.parse("src/com/xml/javaweb/book.xml"); 57 58 //创建节点 59 Element element = d.createElement("售价"); 60 element.setTextContent("39.00元"); 61 62 //添加节点 63 Node node = d.getElementsByTagName("书").item(0); 64 node.appendChild(element); 65 66 //更新XML文档 67 TransformerFactory tff = TransformerFactory.newInstance(); 68 Transformer tf = tff.newTransformer(); 69 tf.transform(new DOMSource(d), new StreamResult(new FileOutputStream("src/com/xml/javaweb/book.xml"))); 70 } 71 72 //向XML文档中指定位置添加节点 <售价>39.00元</售价> 73 @Test 74 public void add2() throws Exception { 75 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 76 DocumentBuilder db = dbf.newDocumentBuilder(); 77 Document d = db.parse("src/com/xml/javaweb/book.xml"); 78 79 //创建节点 80 Element element = d.createElement("售价"); 81 element.setTextContent("29.00元"); 82 83 //得到参考节点 84 Element ref = (Element) d.getElementsByTagName("售价").item(0); 85 86 //添加节点 87 Node node = d.getElementsByTagName("书").item(0); 88 89 //往“书”节点的指定位置插入节点 90 node.insertBefore(element, ref); //在参考节点之前插入新建的节点 91 92 //更新XML文档 93 TransformerFactory tff = TransformerFactory.newInstance(); 94 Transformer tf = tff.newTransformer(); 95 tf.transform(new DOMSource(d), new StreamResult(new FileOutputStream("src/com/xml/javaweb/book.xml"))); 96 } 97 98 99 //向XML文档节点上添加属性 <书名> java就业培训课程</书名> 上添加属性 name = "xxxx" 100 @Test 101 public void add3() throws Exception { 102 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 103 DocumentBuilder db = dbf.newDocumentBuilder(); 104 Document d = db.parse("src/com/xml/javaweb/book.xml"); 105 106 //得到要添加属性的节点 107 Element element= (Element) d.getElementsByTagName("书名").item(0); 108 //往指定节点添加属性 109 element.setAttribute("name", "xxxx"); 110 111 //更新XML文档 112 TransformerFactory tff = TransformerFactory.newInstance(); 113 Transformer tf = tff.newTransformer(); 114 tf.transform(new DOMSource(d), new StreamResult(new FileOutputStream("src/com/xml/javaweb/book.xml"))); 115 } 116 117 118 //删除XML文档节点 <售价>39.00元</售价> 119 @Test 120 public void delete() throws Exception { 121 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 122 DocumentBuilder db = dbf.newDocumentBuilder(); 123 Document d = db.parse("src/com/xml/javaweb/book.xml"); 124 125 //得到要删除的节点 126 Element element= (Element) d.getElementsByTagName("售价").item(1); 127 //得到要删除的节点的父节点 再调用父节点中删除子节点的方法 128 element.getParentNode().removeChild(element); 129 130 //更新XML文档 131 TransformerFactory tff = TransformerFactory.newInstance(); 132 Transformer tf = tff.newTransformer(); 133 tf.transform(new DOMSource(d), new StreamResult(new FileOutputStream("src/com/xml/javaweb/book.xml"))); 134 } 135 136 //更新XML文档节点 <作者>张孝祥</作者> -> <作者>xzk</作者> 137 @Test 138 public void update() throws Exception { 139 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 140 DocumentBuilder db = dbf.newDocumentBuilder(); 141 Document d = db.parse("src/com/xml/javaweb/book.xml"); 142 143 //得到要更新的节点 144 Element element= (Element) d.getElementsByTagName("作者").item(1); 145 //更新该节点的文本 146 element.setTextContent("xzk"); 147 148 //更新XML文档 149 TransformerFactory tff = TransformerFactory.newInstance(); 150 Transformer tf = tff.newTransformer(); 151 tf.transform(new DOMSource(d), new StreamResult(new FileOutputStream("src/com/xml/javaweb/book.xml"))); 152 } 153 }