In Java, how do I parse XML as a String instead of a file?

Question

I have the following code:

DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(xmlFile);

How can I get it to parse XML contained within a String instead of a file?

Also note that javax.xml.parsers.DocumentBuilder.parse(string) assumes the string is a uri (terrible...) — Christophe Roussy
– Christophe Roussy, Commented May 9, 2016 at 13:44

Community · Accepted Answer · 2017-05-23 12:18:16Z

524

I have this function in my code base, this should work for you.

public static Document loadXMLFromString(String xml) throws Exception
{
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    InputSource is = new InputSource(new StringReader(xml));
    return builder.parse(is);
}

also see this similar question

edited May 23, 2017 at 12:18

CommunityBot

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answered Feb 18, 2009 at 18:10

shsteimer

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7 Comments

sattu Over a year ago

@shsteimer I am passing in xml string and it is returning null. It does not throw any exception. What must be wrong?

Alexander Malakhov Over a year ago

@sattu: You should post it as a new question. It's really hard to tell without seeing your code.

Dejell Over a year ago

if I have <?XML> it returns an empty node what can i do?

Daniel Eisenreich Over a year ago

Check that you use the right import statement: import org.xml.sax.InputSource;

John LaBarge Over a year ago

Why is everything in Java so gross? Seriously?

|

Abimaran Kugathasan · Accepted Answer · 2014-06-18 09:26:26Z

20

One way is to use the version of parse that takes an InputSource rather than a file

A SAX InputSource can be constructed from a Reader object. One Reader object is the StringReader

So something like

parse(new InputSource(new StringReader(myString))) may work.

edited Jun 18, 2014 at 9:26

Abimaran Kugathasan

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answered Feb 18, 2009 at 17:59

Uri

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Comments

Christophe Roussy · Accepted Answer · 2016-05-09 13:36:50Z

8

Convert the string to an InputStream and pass it to DocumentBuilder

final InputStream stream = new ByteArrayInputStream(string.getBytes(StandardCharsets.UTF_8));
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
builder.parse(stream);

EDIT
In response to bendin's comment regarding encoding, see shsteimer's answer to this question.

edited May 9, 2016 at 13:36

Christophe Roussy

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answered Feb 18, 2009 at 18:02

Akbar ibrahim

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2 Comments

Michael Myers Over a year ago

I'd prefer the StringReader because it avoids String.getBytes(), but this should usually work also.

bendin Over a year ago

When you call getBytes(), what encoding are you expecting it to use? How are you telling to the XML parser which encoding it's getting? Do you expect it to guess? What happens when you are on a platform where the default encoding isn't UTF-8?

Yasir Shabbir Choudhary · Accepted Answer · 2016-09-07 09:48:58Z

7

I'm using this method

public Document parseXmlFromString(String xmlString){
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    InputStream inputStream = new    ByteArrayInputStream(xmlString.getBytes());
    org.w3c.dom.Document document = builder.parse(inputStream);
    return document;
}

answered Sep 7, 2016 at 9:48

Yasir Shabbir Choudhary

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Comments

duffymo · Accepted Answer · 2009-02-18 17:58:18Z

5

javadocs show that the parse method is overloaded.

Create a StringStream or InputSource using your string XML and you should be set.

answered Feb 18, 2009 at 17:58

duffymo

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Comments

Shukant Pal · Accepted Answer · 2016-10-10 07:25:35Z

0

You can use the Scilca XML Progession package available at GitHub.

XMLIterator xi = new VirtualXML.XMLIterator("<xml />");
XMLReader xr = new XMLReader(xi);
Document d = xr.parseDocument();

answered Oct 10, 2016 at 7:25

Shukant Pal

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Comments

Xinlong Wu · Accepted Answer · 2023-11-10 10:56:05Z

you can try

File f = new File(sac.getFileName());
    if (f.exists()) {
        f.delete();
    }

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    try {

        DocumentBuilder db = dbf.newDocumentBuilder();
        Document doc = db.newDocument();

        // root
        Element root = doc.createElement(Person.KEY_ROOT);
        doc.appendChild(root);

        for(Person p: persons){
            // people element
            Element item = doc.createElement(Person.KEY_ELEMENT);
            root.appendChild(item);

            Element name = doc.createElement(Person.KEY_NAME);
            name.setTextContent(p.getName());
            item.appendChild(name);

            Element gender = doc.createElement(Person.KEY_GENDER);
            gender.setTextContent(p.getGender());
            item.appendChild(gender);

            Element age = doc.createElement(Person.KEY_AGE);
            age.setTextContent(String.valueOf(p.getAge()));
            item.appendChild(age);

            Element occ = doc.createElement(Person.KEY_OCCUPATION);
            occ.setTextContent(p.getOccupation());
            item.appendChild(occ);
        }

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

        transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");

        // INDENT the xml file is optional, you can
        // uncomment the following statement if you would like the xml files to be more
        // readable
        // transformer.setOutputProperty(OutputKeys.INDENT, "yes");

        DOMSource source = new DOMSource(doc);
        StreamResult result = new StreamResult(f);
        transformer.transform(source, result);

    } catch (Exception e) {
        e.printStackTrace();
    }

use following code to load file

File f = new File(lc.getFileName());
    if (!f.exists()) {
        return;
    }

    DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
    DocumentBuilder db;
    try {
        db = dbf.newDocumentBuilder();
        Document doc = db.parse(f);

        doc.getDocumentElement().normalize();

        NodeList nList = doc.getElementsByTagName(Person.KEY_ELEMENT);

        for (int i = 0; i < nList.getLength(); i++) {
            Element element = (Element) nList.item(i);
            Person person = new Person();

            if (element.getElementsByTagName(Person.KEY_NAME).item(0) != null)
                person.setName(element.getElementsByTagName(person.KEY_NAME).item(0).getTextContent());

            if (element.getElementsByTagName(Person.KEY_AGE).item(0) != null)
                person.setAge(Integer.parseInt(element.getElementsByTagName(Person.KEY_AGE).item(0).getTextContent()));

            if (element.getElementsByTagName(Person.KEY_OCCUPATION).item(0) != null)
                person.setOccupation(element.getElementsByTagName(Person.KEY_OCCUPATION).item(0).getTextContent());

            if (element.getElementsByTagName(Person.KEY_GENDER).item(0) != null)
                person.setGender(element.getElementsByTagName(Person.KEY_GENDER).item(0).getTextContent());

            persons.add(person);
        }

        this.db.save(lc.getKey(), persons);

    } catch (Exception e) {
        e.printStackTrace();
    }

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