更新 XML 字符串

Updating an XML String(更新 XML 字符串)

问题描述

从给定的 XML 字符串，我必须更新结束日期值.即使我在 updateNodeValue() 方法中更新 xml，我的最终输出 xml 与输入 xml 相同.

From the given XML String, i have to update End Date value . Even though I'm updating the xml in updateNodeValue() method, my final output xml is same as the input xml.

谁能告诉我这段代码有什么错误

Can someone tell me what is the mistake in this code

import java.io.StringReader;
import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
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;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;


public class MyClass{

    static String strXml = "<INFO><BeginDate>2013-12-02</BeginDate><EndDate>2014-01-31</EndDate></INFO>";

    public static void main(String[] args) throws Exception {

        System.out.println(strXml);
        Document doc = StringToDocument(strXml);
        updateNodeValue(doc);
        String newxml = DocumentToString(doc);
        System.out.println(newxml);

    }

    public static void updateNodeValue(Document doc) {

        Node rootNode = doc.getFirstChild();
        NodeList list = rootNode.getChildNodes();
        for (int i = 0; i < list.getLength(); i++) {

            Element element = (Element) list.item(i);
            Node node = list.item(i);
            if ("EndDate".equals(node.getNodeName())) {
                element.setNodeValue("2013-12-12");
                return;
            }
        }
    }

    public static String DocumentToString(Document doc) throws Exception {

        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer = tf.newTransformer();
        transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
        StringWriter writer = new StringWriter();
        transformer.transform(new DOMSource(doc), new StreamResult(writer));
        String output = writer.getBuffer().toString();
        return output;
    }

    public static Document StringToDocument(String strXml) throws Exception {

        Document doc = null;
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            DocumentBuilder builder = factory.newDocumentBuilder();
            StringReader strReader = new StringReader(strXml);
            InputSource is = new InputSource(strReader);
            doc = (Document) builder.parse(is);
        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        }

        return doc;
    }
}

推荐答案

在你的 updateNodeValue 方法中使用element.setTextContent(...).

Useelement.setTextContent(...) in your updateNodeValue method.

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