Java：将 DOM 写入 XML 文件（格式问题）

使用Java语言编写程序时，我们经常需要将DOM（文档对象模型）写入XML文件。DOM是一种用于表示和操作XML文档的标准方式，它将XML文档解析成一个树状结构，使我们可以方便地对XML进行读取和修改。而将DOM写入XML文件则是将修改后的DOM树重新转化为XML格式，并保存到文件中。

java
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
public class WriteDOMToXML {
    public static void main(String[] args) {
        try {
            // 创建一个新的DOM文档
            DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
            DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
            Document doc = dBuilder.newDocument();
            // 创建根元素
            Element rootElement = doc.createElement("books");
            doc.appendChild(rootElement);
            // 创建子元素
            Element bookElement = doc.createElement("book");
            rootElement.appendChild(bookElement);
            // 添加属性
            bookElement.setAttribute("id", "1");
            // 添加子节点
            Element titleElement = doc.createElement("title");
            titleElement.appendChild(doc.createTextNode("Java编程思想"));
            bookElement.appendChild(titleElement);
            Element authorElement = doc.createElement("author");
            authorElement.appendChild(doc.createTextNode("Bruce Eckel"));
            bookElement.appendChild(authorElement);
            Element yearElement = doc.createElement("year");
            yearElement.appendChild(doc.createTextNode("2007"));
            bookElement.appendChild(yearElement);
            // 将DOM写入XML文件
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);
            StreamResult result = new StreamResult(new File("books.xml"));
            transformer.transform(source, result);
            System.out.println("DOM写入XML文件成功！");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

java
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

java
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.newDocument();

java
Element rootElement = doc.createElement("books");
doc.appendChild(rootElement);

java
Element bookElement = doc.createElement("book");
rootElement.appendChild(bookElement);

java
bookElement.setAttribute("id", "1");

java
Element titleElement = doc.createElement("title");
titleElement.appendChild(doc.createTextNode("Java编程思想"));
bookElement.appendChild(titleElement);
Element authorElement = doc.createElement("author");
authorElement.appendChild(doc.createTextNode("Bruce Eckel"));
bookElement.appendChild(authorElement);
Element yearElement = doc.createElement("year");
yearElement.appendChild(doc.createTextNode("2007"));
bookElement.appendChild(yearElement);

java
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(new File("books.xml"));
transformer.transform(source, result);

java
System.out.println("DOM写入XML文件成功！");