javaee对xml的解析练习

首先是关于xml的文件，我保存的是在src目录下的

exam.xml

<?xml version="1.0" encoding="UTF-8"?><exam>   <student idcard="111" examid="222">     <name>张三</name>      <location>沈阳</location>      <grade>89</grade>   </student>    <student idcard="333" examid="444">     <name>李四</name>      <location>大连</location>      <grade>97</grade>   </student>    <student idcard="555" examid="666">     <name name="ww">王五</name>      <location>武汉</location>      <grade>92</grade>   </student> </exam>

一、首先使用的是jaxp的dom解析实现crud

package xml_csdn_example;import javax.xml.parsers.DocumentBuilder;import javax.xml.parsers.DocumentBuilderFactory;import javax.xml.parsers.ParserConfigurationException;import javax.xml.transform.Transformer;import javax.xml.transform.TransformerConfigurationException;import javax.xml.transform.TransformerFactory;import javax.xml.transform.dom.DOMResult;import javax.xml.transform.dom.DOMSource;import javax.xml.transform.stream.StreamResult;import org.junit.Test;import org.w3c.dom.Document;import org.w3c.dom.Element;import org.w3c.dom.Node;import org.w3c.dom.NodeList;public class XML_JAXP {@Testpublic void test1() throws Exception {/* * 查询所有的元素标签 */Document doc = read();Node item = doc.getElementsByTagName("exam").item(0);getChilder(item);  //采用的是递归函数}private void getChilder(Node item) {// TODO Auto-generated method stubSystem.out.println(item.getNodeName());NodeList list = item.getChildNodes();for(int i=0;i<list.getLength();i++){Node node = list.item(i);getChilder(node);}}//2、查询某一个节点@Testpublic  void test02() throws Exception{Document doc = read();Element selement = (Element) doc.getElementsByTagName("student").item(0);Element celement = (Element) selement.getElementsByTagName("name").item(0);System.out.println(selement.getAttribute("idcard"));System.out.println(selement.getAttribute("examid"));System.out.println(celement.getTextContent());}//3、修改某一个节点//3.1添加一个student@Testpublic  void test03() throws Exception{Document doc = read();Element element = doc.createElement("student");element.setAttribute("idcard", "777");element.setAttribute("examid", "888");//3.3在state中添加City和其他属性Element celement = doc.createElement("name");celement.setTextContent("毛竣锋");element.appendChild(celement);Node root = doc.getElementsByTagName("exam").item(0);root.appendChild(element);write();}

<span style="white-space:pre"></span>//删除@Testpublic  void test04() throws Exception{Document doc = read();Element selement = (Element) doc.getElementsByTagName("student").item(1);Element name = (Element) selement.getElementsByTagName("name").item(0);selement.removeChild(name);write();}//读取操作private Document read() throws Exception {//查找xml，首先创建DocumentBuilderFactory实例 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();//通过DocumentBuilderFactory实例来创建DocumentBuilder实例DocumentBuilder builder = factory.newDocumentBuilder();//通过DocumentBuilder的实例调用parse的方法来读取xml文件Document doc =  builder.parse("src/exam.xml");return doc;}//写操作private void write() throws Exception {//1、通过TransformerFactory来创建实例，调用newInstance方法TransformerFactory factory = TransformerFactory.newInstance();//2、通过TransformerFactory的实例来创建newTransformer对象Transformer transformer = factory.newTransformer();//3、用Transformer的对象的transform方法来修改xml文件transformer.transform(new DOMSource(), new StreamResult("src/exam.xml") );}}

二、采用的是dom4j的工具的方法实现crud

package xml_csdn_example;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.UnsupportedEncodingException;import java.util.List;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.io.OutputFormat;import org.dom4j.io.SAXReader;import org.dom4j.io.XMLWriter;import org.junit.Test;public class XML_DOM4J {//查询，同样是可以采用递归的方法@Testpublic void test01() throws Exception {// TODO Auto-generated method stubDocument doc = read();Element root = doc.getRootElement();List list = root.elements();for(int i=0;i<list.size();i++){System.out.println(list.get(i));}}//增加@Testpublic void test02() throws Exception {Document doc = read();Element root = doc.getRootElement();Element student = root.addElement("student");student.addAttribute("idcard", "777");student.addAttribute("examid", "888");student.addElement("name").addText("毛竣锋");student.addElement("location").addAttribute("address", "龙仙").addText("翁源");student.addElement("grade").addText("100");write(doc);}//修改@Testpublic void test03() throws Exception {Document doc = read();Element root = doc.getRootElement();Element element = (Element) root.elements().get(3);//element.addAttribute("idcard", "123");Element name = (Element) element.elements().get(0);name.setText("暴龙");write(doc);}//删除@Testpublic void test04() throws Exception {Document doc = read();Element root = doc.getRootElement();Element element = (Element) root.elements().get(3);//((Element)element.elements().get(1)).attribute("address").detach();element.detach();write(doc);}//采用dom4j的读取public Document read() throws Exception{SAXReader reader = new SAXReader();Document doc = reader.read("src/exam.xml");return doc;}//采用dom4j的修改private void write(Document doc) throws Exception {// TODO Auto-generated method stubXMLWriter writer = new  XMLWriter(new FileOutputStream("src/exam.xml"),OutputFormat.createPrettyPrint());writer.write(doc);writer.close();}}

三、 采用的是xml解析的sax解析方式

1）第一种方式是直接查询所有的标签

package xml_csdn_example;import java.io.IOException;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;import org.junit.Test;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.XMLReader;import org.xml.sax.helpers.DefaultHandler;public class XML_SAX01 {//sax读取@Testpublic void read() throws Exception {// TODO Auto-generated method stubSAXParserFactory factory = SAXParserFactory.newInstance();SAXParser saxParser = factory.newSAXParser();XMLReader reader = saxParser.getXMLReader();Mycontent m = new Mycontent();reader.setContentHandler(m);reader.parse("src/exam.xml");System.out.println(m.getPath());}}class Mycontent extends DefaultHandler{private String path = "";public String getPath() {return path;}@Overridepublic void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {path += "<"+qName;for(int i =0;i<attributes.getLength();i++){String value = attributes.getValue(i);String name = attributes.getQName(i);path += " " + name + "=\"" + value + "\"";}path +=">";}@Overridepublic void characters(char[] ch, int start, int length)throws SAXException {path +=new String(ch,start,length);}@Overridepublic void endElement(String uri, String localName, String qName)throws SAXException {path +="</" + qName + ">";}}

2）第二种方式是封装为对象，用对象来操作

package xml_example_xpath;import java.util.ArrayList;import java.util.List;import javax.smartcardio.ATR;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;import org.junit.Test;import org.xml.sax.Attributes;import org.xml.sax.SAXException;import org.xml.sax.XMLReader;import org.xml.sax.helpers.DefaultHandler;/* * 关于自主对xml的操作全部元素 */public class Demo5 {@Testpublic void Saxjiexi() throws Exception{SAXParserFactory factory = SAXParserFactory.newInstance();SAXParser saxParser = factory.newSAXParser();XMLReader reader = saxParser.getXMLReader();//Mycontent handler = new Mycontent();//reader.setContentHandler(handler);reader.parse("./src/exam.xml");//System.out.println(handler.getPath());}@Testpublic void Saxentity() throws Exception{SAXParserFactory factory = SAXParserFactory.newInstance();SAXParser saxParser = factory.newSAXParser();XMLReader reader = saxParser.getXMLReader();Mycontent handler = new Mycontent();reader.setContentHandler(handler);reader.parse("./src/exam.xml");List<Student> list = handler.getList();for (Student student : list) {System.out.println(student);}}}class Mycontent extends DefaultHandler{private Student student;private List<Student> list = new ArrayList<Student>();private String curtag;public List<Student> getList() {return list;}@Overridepublic void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {curtag=qName;if("student".equals(qName)){student = new Student();String idcard = attributes.getValue("idcard");String examid = attributes.getValue("examid");student.setExamid(examid);student.setIdcard(idcard);}}@Overridepublic void endElement(String uri, String localName, String qName)throws SAXException {curtag = "";if("student".equals(qName)){list.add(student);}}@Overridepublic void characters(char[] ch, int start, int length)throws SAXException {String content = new String(ch, start, length);if("name".equals(curtag)){student.setName(content);}if("location".equals(curtag)){student.setLocation(content);}if("grade".equals(curtag)){student.setGrade(content);}}}

通过这两天对xml的比较系统的学习，了解了两种解析的方法及作用，也算为xml打下了一个比较扎实的基础