DOM 文档对象模型
基于XML文档树结构解析
适用于多次访问的xml文档
特点:比较消耗资源
1).Document对象
NodeList getElementsByTagName(String name):指定节点名称的元素集合,返回NodeList对象
Element getDocumentElement():
2).NodeList对象
指包含了一个或者多个节点(Node)的列表.
getLength():返回列表的长度.
item(int index):返回指定位置的Node对象
3).Node对象
getChildNodes():包含此节点的所有子节点的NodeList
getFirstChild():如果节点存在子节点,则返回第一个子节点
getLastChild():如果节点存在子节点,则返回最后一个子节点
getNextSibling():返回在DOM树中这个节点的下一个兄弟节点
getPreviousSibling():返回在DOM树中这个节点的上一个兄弟节点
getNodeName():返回节点的名称
getNodeValue():返回节点的值
getNodeType():返回节点的类型
4).Element对象
Node的子对象
getAttribute(String attributename):返回标签中给定属性名称的属性的值
getElementsByTagName(String name):返回具有给定标记名称的所有后代Elements的NodeList
if (typeNode.getNodeType()==Node.ELEMENT_NODE):判断是否为元素节点
//添加子节点
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db;
try {
db = dbf.newDocumentBuilder();
Document document = db.parse("src/com/xml/PhoneInfo.xml");
//创建Brand节点
Element element = document.createElement("Brand");
element.setAttribute("name", "MOTO");
//创建Type节点
Element typElement = document.createElement("Type");
typElement.setAttribute("name", "摩托罗拉");
//创建Item节点
Element itemeElement = document.createElement("Item");
//添加父子关系
typElement.appendChild(itemeElement);
element.appendChild(typElement);
Element phoneElement = (Element)document.getElementsByTagName("PhoneInfo").item(0);
phoneElement.appendChild(element);
//保存xml文件
TransformerFactory tff = TransformerFactory.newInstance();
try {
Transformer transformer = tff.newTransformer();
DOMSource domSource = new DOMSource(document);
//设置编码类型
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
StreamResult result = new StreamResult(new FileOutputStream("src/com/xml/PhoneInfo.xml"));
//把DOM树转换成XML文件
transformer.transform(domSource, result);
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//修改子节点
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db;
try {
db = dbf.newDocumentBuilder();
Document document = db.parse("src/com/xml/PhoneInfo.xml");
NodeList nodeList = document.getElementsByTagName("Type");
for (int i=0;i<nodeList.getLength();i++){
Element element = (Element)nodeList.item(i);
String brandName = element.getAttribute("name");
System.out.println("修改前:"+brandName);
if ("iphone4".equals(brandName)){
element.setAttribute("name", "iPad");
}
}
//保存xml文档
TransformerFactory tff = TransformerFactory.newInstance();
try {
Transformer transformer = tff.newTransformer();
DOMSource domSource = new DOMSource(document);
//设置编码类型
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
StreamResult result = new StreamResult(new FileOutputStream("src/com/xml/PhoneInfo.xml"));
//把DOM树转换成XML文件
transformer.transform(domSource, result);
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//删除节点
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder db = dbf.newDocumentBuilder();
Document document = db.parse("src/com/xml/PhoneInfo.xml");
NodeList list = document.getElementsByTagName("Brand");
for (int i=0;i<list.getLength();i++){
Element element = (Element)list.item(i);
String brandName = element.getAttribute("name");
if ("MOHAHA".equals(brandName)){
element.getParentNode().removeChild(element);
}
}
//保存文件
TransformerFactory tff = TransformerFactory.newInstance();
try {
Transformer transformer = tff.newTransformer();
DOMSource domSource = new DOMSource(document);
//设置编码类型
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
StreamResult result = new StreamResult(new FileOutputStream("src/com/xml/PhoneInfo.xml"));
//把DOM树转换成XML文件
transformer.transform(domSource, result);
} catch (TransformerConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TransformerException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (ParserConfigurationException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SAXException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
设置缩进:
①
TransformerFactory tff = TransformerFactory.newInstance();
tff.setAttribute("indent-number", 4);
②
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
StreamResult result = new StreamResult(new OutputStreamWriter(new FileOutputStream("src/com/xml/Phone.xml"),"utf-8"));