Question

我正在尝试更改活动A04的PlannedDuration，但无法看到XML文件中的更改。所做的更改不会更新到文件中。我不知道我在做什么错。

XML太长。该文件包含有关多个活动的信息。我只对ID A04的活动感兴趣。

PlannedDuration的初始值为16，我将其更改为25。

package modifyXML;

import java.io.File;
import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
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 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 ModifyXML{

    public static void main(String[] args) {

        File xmlfile = new File("C:/Users/dianitaf/Downloads/xml Files/CS_1.xml");
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder;

        try {
            dBuilder = dbFactory.newDocumentBuilder();
            Document document = dBuilder.parse(xmlfile);
            document.getDocumentElement().normalize();

            updateElementValue(document,"Id", "A04");

            document.getDocumentElement().normalize();

            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();

            DOMSource source = new DOMSource(document);

            StreamResult result = new StreamResult(new File("xmlfile"));

            transformer.transform(source, result);

            System.out.println("XML file updated successfully");

        } catch (SAXException | ParserConfigurationException | IOException | TransformerException e1) {
            e1.printStackTrace();
        }
    }

    private static void updateElementValue(Document document, String textNodeName, String textNodeValue) {

        NodeList Activity = document.getElementsByTagName("Activity");
        Element act = null;

        //loop for each activity
        for(int i=0; i<Activity.getLength();i++){

            Node activityNode = Activity.item(i);
            if(activityNode.getNodeType() == Node.ELEMENT_NODE)
            {
                Element activityElement = (Element) activityNode;
                NodeList textNodes = activityElement.getElementsByTagName(textNodeName); 

                if(textNodes.getLength() > 0)
                {

                    if(textNodes.item(0).getTextContent().equalsIgnoreCase(textNodeValue))
                    {

                        System.out.println(textNodes.item(0).getTextContent());
                        System.out.println(activityElement.getElementsByTagName("Name").item(0).getTextContent());

                        act = (Element) Activity.item(i);     
                        Node duration = act.getElementsByTagName("PlannedDuration").item(0).getFirstChild();

                        System.out.println("Initial Duration : " + act.getElementsByTagName("PlannedDuration").item(0).getTextContent()); act.getElementsByTagName("PlannedDuration").item(0).getTextContent();

                        duration.setTextContent("25");

                        System.out.println("Updaded Duration : " + act.getElementsByTagName("PlannedDuration").item(0).getTextContent());
                    }
                }    
            }
        }
    }
}

Answer 1

XML：

<?xml version="1.0" encoding="UTF-8" standalone="no"?><APIBusinessObjects> 
    <ProjectList>
        <Project ObjectId="4627">
            <Id>CS_1</Id>
            <Name>Case Study No.1 Warehouse Project - CPM</Name>
        </Project>
    </ProjectList> 
    <Project>
        <Activity>
            <Id>A04</Id>
            <Name>Nailers to Purlins</Name>
            <PlannedDuration>16</PlannedDuration>
            <StartDate>2018-12-26Te8:00:00</StartDate>
        </Activity> 
    </Project>
</APIBusinessObjects>

Java：

package modifyXML;

import java.io.File;
import java.io.IOException;
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 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 ModifyXML {

    public static void main(String[] args) {

        File xmlfile = new File("D:\\delete\\test.xml");
        DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
        DocumentBuilder dBuilder;

        try {
            dBuilder = dbFactory.newDocumentBuilder();
            Document document = dBuilder.parse(xmlfile);
            document.getDocumentElement().normalize();

            updateElementValue(document, "Id", "A04");

            document.getDocumentElement().normalize();

            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();

            DOMSource source = new DOMSource(document);

            StreamResult result = new StreamResult(xmlfile);

            transformer.transform(source, result);

            System.out.println("XML file updated successfully");

        } catch (SAXException | ParserConfigurationException | IOException | TransformerException e1) {
            e1.printStackTrace();
        }
    }

    private static void updateElementValue(Document document, String textNodeName, String textNodeValue) {

        NodeList Activity = document.getElementsByTagName("Activity");
        Element act = null;

        // loop for each activity
        for (int i = 0; i < Activity.getLength(); i++) {

            Node activityNode = Activity.item(i);
            if (activityNode.getNodeType() == Node.ELEMENT_NODE) {
                Element activityElement = (Element) activityNode;
                NodeList textNodes = activityElement.getElementsByTagName(textNodeName);

                if (textNodes.getLength() > 0) {

                    if (textNodes.item(0).getTextContent().equalsIgnoreCase(textNodeValue)) {

                        System.out.println(textNodes.item(0).getTextContent());
                        System.out.println(activityElement.getElementsByTagName("Name").item(0).getTextContent());

                        act = (Element) Activity.item(i);
                        Node duration = act.getElementsByTagName("PlannedDuration").item(0).getFirstChild();

                        System.out.println("Initial Duration : "
                                + act.getElementsByTagName("PlannedDuration").item(0).getTextContent());
                        act.getElementsByTagName("PlannedDuration").item(0).getTextContent();

                        duration.setTextContent("25");

                        System.out.println("Updaded Duration : "
                                + act.getElementsByTagName("PlannedDuration").item(0).getTextContent());
                    }
                }
            }
        }
    }
}

用Java更新XML

1 个答案: