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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>
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 {
@Test
public 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 stub
System.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
@Test
public 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
@Test
public 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
@Test
public 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") );
}
}
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
@Test
public void test01() throws Exception {
// TODO Auto-generated method stub
Document 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
@Test
public 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
@Test
public 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
@Test
public 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 stub
XMLWriter writer = new XMLWriter(
new FileOutputStream("src/exam.xml"),
OutputFormat.createPrettyPrint()
);
writer.write(doc);
writer.close();
}
}
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
@Test
public void read() throws Exception {
// TODO Auto-generated method stub
SAXParserFactory 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;
}
@Override
public 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 +=">";
}
@Override
public void characters(char[] ch, int start, int length)
throws SAXException {
path +=new String(ch,start,length);
}
@Override
public 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 {
@Test
public 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());
}
@Test
public 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;
}
@Override
public 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);
}
}
@Override
public void endElement(String uri, String localName, String qName)
throws SAXException {
curtag = "";
if("student".equals(qName)){
list.add(student);
}
}
@Override
public 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);
}
}
}
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原文地址：http://blog.csdn.net/css1223mjf/article/details/51915567
