Java Convert String to XML Document and XML Document to String With Examples [Latest]

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.