Java: Append to XML File

Question

I have the below code that writes to an xml file, the problem that I am having is that it creates a new file every time i write to it and overwrites the other data saved in the file. I am looking for a solution that would append to the existing file instead. How do I modify this code to append to the file each time instead of overwrite? Also, I am using the netbeans IDE to run this program.

import java.io.File;
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.xml.sax.SAXException;
public class WriteXMLFile {

    public static void main() throws ParserConfigurationException,SAXException,Exception
    {
        DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();//
        DocumentBuilder docBuilder = docFactory.newDocumentBuilder();//

        Document doc = docBuilder.newDocument();// this is difrent

        Element rootElement = doc.createElement("Contacts");//
        doc.appendChild(rootElement); // this is difrent
        // staff elements

        Element Contact1 = doc.createElement("Contact1");
        rootElement.appendChild(Contact1);
        // set attribute to staff element

        Contact1.setAttribute("id","1");

        // firstname elements

        Element firstname = doc.createElement("Name");
        firstname.appendChild(doc.createTextNode(EmailFrame.name.getText()));
        Contact1.appendChild(firstname); 

        //Email Element
        Element email = doc.createElement("Email");
        email.appendChild(doc.createTextNode(EmailFrame.email.getText()));
        Contact1.appendChild(email); 

        // phone element
        Element phone= doc.createElement("Phone");
        phone.appendChild(doc.createTextNode(EmailFrame.phone.getText()));
        Contact1.appendChild(phone);
        //id element
        Element id = doc.createElement("ID");
        id.appendChild(doc.createTextNode(EmailFrame.id.getText()));
        Contact1.appendChild(id); 

        try{
            // write the content into xml file
            TransformerFactory transformerFactory = TransformerFactory.newInstance();
            Transformer transformer = transformerFactory.newTransformer();
            DOMSource source = new DOMSource(doc);


            StreamResult result = new StreamResult(new File("C:/Users/steve/Desktop/xmlemail/Email.xml"));

            transformer.transform(source, result);
            System.out.println("File saved!");
        }
        catch (TransformerException tfe) {
            tfe.printStackTrace();
        }
    }
}

That question is modifying the file, not appending to an existing file. — Steven, Nov 10 '17 at 16:14
Same thing: read the content first, modify it while it's in-memory, and write it back. — Nir Alfasi, Nov 10 '17 at 16:17

Ayo K · Accepted Answer · 2017-11-10T16:15:42.260

2

What you need to do is read the contents of the xml file into an object first before writing, then append your new content to your object then write your object to the xml file

Look at this resource for reading an xml file it should help

https://www.mkyong.com/java/how-to-read-xml-file-in-java-dom-parser/

edited Nov 10 '17 at 16:15

answered Nov 10 '17 at 16:08

Ayo K

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any samples on how to do that based on the code i have? – Steven Nov 10 '17 at 16:12

Java: Append to XML File

1 Answers1