Java操作XML文件

<?xml version="1.0" encoding="UTF-8"?>

<Students>
  <Student id="001">
    <name>张三</name>
    <age>19</age>
    <gender>男</gender>
    <grade>计算机1班</grade>
  </Student>
  <Student id="002">
    <name>李四</name>
    <age>20</age>
    <gender>男</gender>
    <grade>计算机2班</grade>
  </Student>
</Students>

package xml;

import java.io.File;
import java.util.List;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

public class ReadAndPrintXML {
	public static void main(String[] args) throws Exception {
		// 创建一个XML解析器对象
		SAXReader reader = new SAXReader();
		// 读取XML文档，返回Document对象
		Document document = reader.read(new File("E:\\xml\\students.xml"));
		
		// 获取根元素节点
		Element root = document.getRootElement();
		StringBuilder sb = new StringBuilder();
		recursion(root, sb);
		System.out.println(sb.toString());
	}
	
	private static void recursion(Element ele, StringBuilder sb) {
		sb.append("<");
		// 解析元素节点
		sb.append(ele.getName());
		
		// 解析属性节点
		List<Attribute> attributes = ele.attributes();
		for(Attribute attribute : attributes) {
			sb.append(" ");
			sb.append(attribute.getName());
			sb.append("=");
			sb.append(attribute.getValue());
		}
		
		sb.append(">");
		
		// 解析文本节点
		sb.append(ele.getText());
		
		// 递归解析元素节点
		List<Element> elements = ele.elements();
		for(Element element : elements) {
			recursion(element, sb);
		}
		
		sb.append("<" + ele.getName() + "/>\n");
	}

}

import java.io.FileOutputStream;
import java.io.UnsupportedEncodingException;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.XMLWriter;

public class WriteXML {
	public static void main(String[] args) throws Exception {
		// 创建一个XMLWriter对象
		OutputFormat format = OutputFormat.createPrettyPrint();
		XMLWriter writer = new XMLWriter(new FileOutputStream("E:\\xml\\students2.xml"), format);
		// 生成一个新的Document对象
		Document doc = DocumentHelper.createDocument();
		// 增加Students元素节点
		Element students = doc.addElement("Students");
		// 增加两个Student元素节点
		Element student1 = students.addElement("student");
		Element student2 = students.addElement("student");
		// 为两个Student元素节点分别增加id属性节点
		student1.addAttribute("id", "001");
		student2.addAttribute("id", "002");
		// 分别增加name, age, gender, grade元素子节点
		student1.addElement("name").setText("张三");
		student1.addElement("age").setText("19");
		student1.addElement("gender").setText("男");
		student1.addElement("grade").setText("计算机1班");
		student2.addElement("name").setText("李四");
		student2.addElement("age").setText("20");
		student2.addElement("gender").setText("男");
		student2.addElement("grade").setText("计算机2班");
		// 将Document对象写入磁盘
		writer.write(doc);
		writer.close();
	}
}

import java.io.File;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;

public class XPathTest {
	public static void main(String[] args) throws Exception {
		SAXReader reader = new SAXReader();
		Document doc = reader.read(new File("E:\\xml\\students.xml"));
		
		// 选择所有的student元素
		List<Node> list = doc.selectNodes("//Student");
		
		// 选择文本内容是"张三"的name元素
		Element name = (Element) doc.selectSingleNode("//name[text()='张三']");
		
		// 选择所有id属性节点
		List<Node> list2 = doc.selectNodes("//@id");
		
		// 选择id属性为002的student元素
		Element student = (Element) doc.selectSingleNode("//Student[@id='002']");
		
		// 选择根元素节点的所有子节点
		Element root = doc.getRootElement();
		List<Node> list3 = doc.selectNodes("/Students/*");
	}
}

import java.io.File;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

public class SAXTest {
	public static void main(String[] args) throws Exception {
		SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
		parser.parse(new File("E:\\xml\\students.xml"), new MyDefaultHandler());
	}
}

class MyDefaultHandler extends DefaultHandler{
	@Override
	public void startDocument() throws SAXException {
		System.out.println("----文档开始解析-------");
	}
	
	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
		System.out.print("<" + qName);
		
		for(int i = 0; i < attributes.getLength(); i++) {
			System.out.print(" " + attributes.getQName(i) + "=" + attributes.getValue(i));
		}
		System.out.print(">");
	}
	
	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
		System.out.print(new String(ch, start, length));
	}
	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException {
		System.out.print("</" + qName + ">");
	}
	
	@Override
	public void endDocument() throws SAXException {
		System.out.println("\n----文档开始解析结束-----");
	}
}