Java中使用DOM方式解析和创建XML文档、及dom4j使用简介
1.解析XML文档
Java代码
package peixun;
import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class ReadXML {
public static void main(String[] args) {
try {
//DOM方式解析XML文档
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();//调用DocumentBuilderFactory类，使用DocumentBuilderFactory的静态方法获取一个新的实例
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.parse(new File("languages.xml"));
Element root = document.getDocumentElement();
System.out.println("cat="+root.getAttribute("cat"));
NodeList list = root.getElementsByTagName("lan");
for (int i = 0; i < list.getLength(); i++) {
Element lan = (Element) list.item(i);
System.out.println("-------------------");
System.out.println("id="+lan.getAttribute("id"));
NodeList clist = lan.getChildNodes();
for (int j = 0; j < clist.getLength(); j++) {
Node c = clist.item(j);
//c instanceof Element是为了不输出不可见的字节
if (c instanceof Element) {
System.out.println(c.getNodeName()+"="+c.getTextContent());
}
}
}
}
catch (SAXException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
catch (ParserConfigurationException e) {
e.printStackTrace();
}
}
}
XML文档
<?xml version="1.0" encoding="UTF-8"?>
<Language cat="it">
<lan id="1">
<name>Java</name>
<ide>Eclipse</ide>
</lan>
<lan id="2">
<name>Swift</name>
<ide>Xcode</ide>
</lan>
<lan id="3">
<name>C#</name>
<ide>Visual Studio</ide>
</lan>
</Language>2.创建XML文档
Java代码：
package peixun;
import java.io.File;
import java.io.StringWriter;
import java.nio.file.Path;
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.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
public class CreateXML {
public static void main(String[] args) {
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.newDocument();
Element root = document.createElement("Languages");
root.setAttribute("cat", "it");
Element lan1 = document.createElement("lan");
lan1.setAttribute("id", "1");
Element name1 = document.createElement("name");
name1.setTextContent("Swift");
Element ide1 = document.createElement("ide");
ide1.setTextContent("Xcode");
//name和ide添加到lan的子节点
lan1.appendChild(name1);
lan1.appendChild(ide1);
//lan节点添加到root节点下
root.appendChild(lan1);
//root添加到document中
document.appendChild(root);
Element lan2 = document.createElement("lan");
lan2.setAttribute("id", "2");
Element name2 = document.createElement("name");
name2.setTextContent("C#");
Element ide2 = document.createElement("ide");
ide2.setTextContent("Visual Studio");
//name和ide添加到lan的子节点
lan1.appendChild(name2);
lan1.appendChild(ide2);
//lan节点添加到root节点下
root.appendChild(lan2);
Element lan3 = document.createElement("lan");
lan3.setAttribute("id", "3");
Element name3 = document.createElement("name");
name3.setTextContent("Java");
Element ide3 = document.createElement("ide");
ide3.setTextContent("eclipse");
//name和ide添加到lan的子节点
lan1.appendChild(name3);
lan1.appendChild(ide3);
//lan节点添加到root节点下
root.appendChild(lan3);
//----------
TransformerFactory transformerFactory = TransformerFactory.newInstance();
//transformer将XML文档转化成其他格式
Transformer transformer = transformerFactory.newTransformer();
StringWriter writer = new StringWriter();
//字符流形式输出
transformer.transform(new DOMSource(document),new StreamResult(writer));
System.out.println(writer.toString());
//以文件形式输出
transformer.transform(new DOMSource(document),new StreamResult(new File("newxml.xml")));
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
}
}
}
3.dom4j使用简介
package peixun;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
public class Testdom4j {
public static void main(String[] args) {
try {
String xmlString = "<root><people>Sai</people></root>";
//把xmlString字符串转换成document对象
Document document = DocumentHelper.parseText(xmlString);
//将document对象输出成字符串
System.out.println(document.asXML());
} catch (DocumentException e) {
e.printStackTrace();
}
}
}