// Tutorial //

Java Convert String to XML Document and XML Document to String

Published on August 3, 2022
Default avatar
By Pankaj
Developer and author at DigitalOcean.
Java Convert String to XML Document and XML Document to String

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Sometimes while programming in java, we get String which is actually an XML and to process it, we need to convert it to XML Document (org.w3c.dom.Document). Also for debugging purpose or to send to some other function, we might need to convert Document object to String. Here I am providing two utility functions.

  1. Document convertStringToDocument(String xmlStr): This method will take input as String and then convert it to DOM Document and return it. We will use InputSource and StringReader for this conversion.
  2. String convertDocumentToString(Document doc): This method will take input as Document and convert it to String. We will use Transformer, StringWriter and StreamResult for this purpose.
package com.journaldev.xml;

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.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.xml.sax.InputSource;

public class StringToDocumentToString {

    public static void main(String[] args) {
        final String xmlStr = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n"+
                                "<Emp id=\"1\"><name>Pankaj</name><age>25</age>\n"+
                                "<role>Developer</role><gen>Male</gen></Emp>";
        Document doc = convertStringToDocument(xmlStr);
        
        String str = convertDocumentToString(doc);
        System.out.println(str);
    }

    private static String convertDocumentToString(Document doc) {
        TransformerFactory tf = TransformerFactory.newInstance();
        Transformer transformer;
        try {
            transformer = tf.newTransformer();
            // below code to remove XML declaration
            // 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;
        } catch (TransformerException e) {
            e.printStackTrace();
        }
        
        return null;
    }

    private static Document convertStringToDocument(String xmlStr) {
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  
        DocumentBuilder builder;  
        try  
        {  
            builder = factory.newDocumentBuilder();  
            Document doc = builder.parse( new InputSource( new StringReader( xmlStr ) ) ); 
            return doc;
        } catch (Exception e) {  
            e.printStackTrace();  
        } 
        return null;
    }

}

When we run above program, we get the same String output that we used to create DOM Document.

<?xml version="1.0" encoding="UTF-8"?><Emp id="1"><name>Pankaj</name><age>25</age>
<role>Developer</role><gen>Male</gen></Emp>

You can use replaceAll("\n|\r", "") to remove new line characters from String and get it in compact format.


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About the authors
Default avatar
Pankaj

author

Developer and author at DigitalOcean.

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Was this helpful?

Is there any way to handle the converion for large document, as while convesion toString getting out of memory error.

- Ankit

    Can you provide me a example for “Document convertStringToDocument(String xmlStr)” I am currently working on one of the project where I need to convert string to xml format

    - Akshay A

      Works great for me, thanks!

      - Carlos Barrantes

        Thanks a lot for sharing this. :).

        - Nik

          Why is this article still up and why is the author not responding to so many people saying it doesn’t work. The code does not work.

          - Raj Ashtaputre

            why the doc value is null then how we can get our xml data

            - Mahadev

              Hi all, i am also getting same error on parsing…Null pointer exception gets genearted…Any help is highly appreciaed

              - Mehul Kishor Fatnani

                Where is the replaceAll() method supposed to be used? I was thinking it should be placed on the string str before printing it out, like so: String str = convertDocumentToString(doc); str.replaceAll(“\n|\r”, “”); System.out.println(str); But the output doesn’t change…

                - nekonutchi

                  The variable doc allways return null

                  - mmonikm

                    successfully executed but did not found useful. I want convert doc file into xml

                    - ahmad