Java从Document中获取xml字符串

在Java开发中，我们经常需要从Document中获取XML字符串。XML是一种被广泛应用于数据传输和存储的标记语言，它具有良好的可读性和扩展性。在本文中，我们将学习如何使用Java从Document对象中提取XML字符串，并提供一些案例代码来帮助理解。

java
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

java
// 创建一个Document对象
Document document = ...; // 这里是获取Document对象的方法，可以根据具体情况进行调整

java
public static String documentToXmlString(Document document) throws TransformerException {
    // 创建TransformerFactory对象
    TransformerFactory transformerFactory = TransformerFactory.newInstance();
    // 创建Transformer对象
    Transformer transformer = transformerFactory.newTransformer();
    // 将Document对象转换为DOMSource对象
    DOMSource domSource = new DOMSource(document);
    // 创建StreamResult对象，用于存储转换后的结果
    StreamResult streamResult = new StreamResult(new StringWriter());
    // 执行转换
    transformer.transform(domSource, streamResult);
    // 获取转换后的XML字符串
    String xmlString = streamResult.getWriter().toString();
    // 返回XML字符串
    return xmlString;
}

java
import org.w3c.dom.Document;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.StringWriter;
public class DocumentToXmlStringExample {
    public static void main(String[] args) {
        try {
            // 创建一个Document对象
            Document document = createDocument();
            // 将Document对象转换为XML字符串
            String xmlString = documentToXmlString(document);
            // 输出XML字符串
            System.out.println(xmlString);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static Document createDocument() throws ParserConfigurationException {
        // 创建DocumentBuilderFactory对象
        DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
        // 创建DocumentBuilder对象
        DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
        // 创建一个新的Document对象
        Document document = documentBuilder.newDocument();
        // 创建根元素
        Element rootElement = document.createElement("employees");
        document.appendChild(rootElement);
        // 创建子元素
        Element employeeElement = document.createElement("employee");
        rootElement.appendChild(employeeElement);
        // 添加属性
        Attr idAttribute = document.createAttribute("id");
        idAttribute.setValue("1");
        employeeElement.setAttributeNode(idAttribute);
        // 添加子元素
        Element nameElement = document.createElement("name");
        nameElement.appendChild(document.createTextNode("John Doe"));
        employeeElement.appendChild(nameElement);
        return document;
    }
    public static String documentToXmlString(Document document) throws TransformerException {
        // 创建TransformerFactory对象
        TransformerFactory transformerFactory = TransformerFactory.newInstance();
        // 创建Transformer对象
        Transformer transformer = transformerFactory.newTransformer();
        // 将Document对象转换为DOMSource对象
        DOMSource domSource = new DOMSource(document);
        // 创建StreamResult对象，用于存储转换后的结果
        StreamResult streamResult = new StreamResult(new StringWriter());
        // 执行转换
        transformer.transform(domSource, streamResult);
        // 获取转换后的XML字符串
        String xmlString = streamResult.getWriter().toString();
        // 返回XML字符串
        return xmlString;
    }
}