Java生成XML的缩进和换行

一 DOM 以下代码用DOM是生成一个XML文档
package xml;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
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 XMLHandler {
public void createXML() throws FileNotFoundException {
Document doc = null;
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
try {
DocumentBuilder docBuilder = dbf.newDocumentBuilder();
doc = docBuilder.newDocument();
Element root = doc.createElement("root");
doc.appendChild(root);
Element country = doc.createElement("contry");
country.appendChild(doc.createTextNode("China"));
root.appendChild(country);
Element city = doc.createElement("city");
city.appendChild(doc.createTextNode("Beijing"));
country.appendChild(city);

city = doc.createElement("city");
city.appendChild(doc.createTextNode("Shanghai"));
country.appendChild(city);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
File file = new File("E://cities.xml");
FileOutputStream out = new FileOutputStream(file);
StreamResult xmlResult = new StreamResult(out);
transformer.transform(new DOMSource(doc), xmlResult);
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (TransformerConfigurationException e) {
e.printStackTrace();
} catch (TransformerException e) {
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
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