DOM方式解析XML
Dom解析是将xml文件全部载入到内存，组装成一颗dom树，然后通过节点以及节点之间的关系来解析xml文件,与平台无关,java提供的一种基础的解析XML文件的API,理解较简单，但是由于整个文档都需要载入内存,不适用于文档较大时。 （推荐学习：java课程）
SAX方式解析XML
基于事件驱动,逐条解析,适用于只处理xml数据，不易编码,而且很难同时访问同一个文档中的多处不同数据
JDOM方式解析XML
简化与XML的交互并且比使用DOM实现更快,仅使用具体类而不使用接口因此简化了API,并且易于使用
DOM4j方式解析XML
JDOM的一种智能分支,功能较强大，建议熟练使用
xml文件
<?xml version="1.0" encoding="utf-8" ?><class> <student> <firstname>cxx1</firstname> <lastname>Bob1</lastname> <nickname>stars1</nickname> <marks>85</marks> </student> <student rollno="493"> <firstname>cxx2</firstname> <lastname>Bob2</lastname> <nickname>stars2</nickname> <marks>85</marks> </student> <student rollno="593"> <firstname>cxx3</firstname> <lastname>Bob3</lastname> <nickname>stars3</nickname> <marks>85</marks> </student></class>
DOM方式
package com.cxx.xml;import org.w3c.dom.*;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;/** * @Author: cxx * Dom操作xml * @Date: 2018/5/29 20:19 */public class DomDemo { //用Element方式 public static void element(NodeList list){ for (int i = 0; i <list.getLength() ; i++) { Element element = (Element) list.item(i); NodeList childNodes = element.getChildNodes(); for (int j = 0; j <childNodes.getLength() ; j++) { if (childNodes.item(j).getNodeType()==Node.ELEMENT_NODE) { //获取节点 System.out.print(childNodes.item(j).getNodeName() + ":"); //获取节点值 System.out.println(childNodes.item(j).getFirstChild().getNodeValue()); } } } } public static void node(NodeList list){ for (int i = 0; i <list.getLength() ; i++) { Node node = list.item(i); NodeList childNodes = node.getChildNodes(); for (int j = 0; j <childNodes.getLength() ; j++) { if (childNodes.item(j).getNodeType()==Node.ELEMENT_NODE) { System.out.print(childNodes.item(j).getNodeName() + ":"); System.out.println(childNodes.item(j).getFirstChild().getNodeValue()); } } } } public static void main(String[] args) { //1.创建DocumentBuilderFactory对象 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); //2.创建DocumentBuilder对象 try { DocumentBuilder builder = factory.newDocumentBuilder(); Document d = builder.parse("src/main/resources/demo.xml"); NodeList sList = d.getElementsByTagName("student"); //element(sList); node(sList); } catch (Exception e) { e.printStackTrace(); } }}SAX方式
package com.cxx.xml;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.helpers.DefaultHandler;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;/** * @Author: cxx * SAX解析DOM * 一行一行 Handler * startElement * endElement * @Date: 2018/5/29 20:03 */public class SaxDemo { public static void main(String[] args) throws Exception { //1.或去SAXParserFactory实例 SAXParserFactory factory = SAXParserFactory.newInstance(); //2.获取SAXparser实例 SAXParser saxParser = factory.newSAXParser(); //创建Handel对象 SAXDemoHandel handel = new SAXDemoHandel(); saxParser.parse("src/main/resources/demo.xml",handel); }}class SAXDemoHandel extends DefaultHandler { //遍历xml文件开始标签 @Override public void startDocument() throws SAXException { super.startDocument(); System.out.println("sax解析开始"); } //遍历xml文件结束标签 @Override public void endDocument() throws SAXException { super.endDocument(); System.out.println("sax解析结束"); } @Override public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { super.startElement(uri, localName, qName, attributes); if (qName.equals("student")){ System.out.println("============开始遍历student============="); //System.out.println(attributes.getValue("rollno")); } else if (!qName.equals("student")&&!qName.equals("class")){ System.out.print("节点名称:"+qName+"----"); } } @Override public void endElement(String uri, String localName, String qName) throws SAXException { super.endElement(uri, localName, qName); if (qName.equals("student")){ System.out.println(qName+"遍历结束"); System.out.println("============结束遍历student============="); } } @Override public void characters(char[] ch, int start, int length) throws SAXException { super.characters(ch, start, length); String value = new String(ch,start,length).trim(); if (!value.equals("")) { System.out.println(value); } }}JDOM方式
<!--jdom --><dependency> <groupId>org.jdom</groupId> <artifactId>jdom</artifactId> <version>1.1.3</version></dependency>
package com.cxx.xml;import org.jdom.Attribute;import org.jdom.Document;import org.jdom.Element;import org.jdom.input.SAXBuilder;import java.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.InputStream;import java.util.List;/** * @Author: cxx * JDom解析xml * 快速开发XML应用程序。 * 是一个开源项目 * JDOM主要用来弥补DOM和SAX在实际应用当中的不足。 * @Date: 2018/5/30 11:44 */public class JDomDemo { public static void main(String[] args) throws Exception { //1.创建SAXBuilder对象 SAXBuilder saxBuilder = new SAXBuilder(); //2.创建输入流 InputStream is = new FileInputStream(new File("src/main/resources/demo.xml")); //3.将输入流加载到build中 Document document = saxBuilder.build(is); //4.获取根节点 Element rootElement = document.getRootElement(); //5.获取子节点 List<Element> children = rootElement.getChildren(); for (Element child : children) { System.out.println("通过rollno获取属性值:"+child.getAttribute("rollno")); List<Attribute> attributes = child.getAttributes(); //打印属性 for (Attribute attr : attributes) { System.out.println(attr.getName()+":"+attr.getValue()); } List<Element> childrenList = child.getChildren(); System.out.println("======获取子节点-start======"); for (Element o : childrenList) { System.out.println("节点名:"+o.getName()+"---"+"节点值:"+o.getValue()); } System.out.println("======获取子节点-end======"); } }}DOM4J方式
<!-- dom4j --> <dependency> <groupId>dom4j</groupId> <artifactId>dom4j</artifactId> <version>1.6.1</version></dependency>
package com.cxx.xml;import org.dom4j.Attribute;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.io.SAXReader;import java.io.File;import java.util.Iterator;import java.util.List;/** * @Author: cxx * Dom4j解析xml * @Date: 2018/5/30 12:21 */public class Dom4JDemo { public static void main(String[] args) throws Exception { //1.创建Reader对象 SAXReader reader = new SAXReader(); //2.加载xml Document document = reader.read(new File("src/main/resources/demo.xml")); //3.获取根节点 Element rootElement = document.getRootElement(); Iterator iterator = rootElement.elementIterator(); while (iterator.hasNext()){ Element stu = (Element) iterator.next(); List<Attribute> attributes = stu.attributes(); System.out.println("======获取属性值======"); for (Attribute attribute : attributes) { System.out.println(attribute.getValue()); } System.out.println("======遍历子节点======"); Iterator iterator1 = stu.elementIterator(); while (iterator1.hasNext()){ Element stuChild = (Element) iterator1.next(); System.out.println("节点名："+stuChild.getName()+"---节点值："+stuChild.getStringValue()); } } }}
