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?

Solution 1

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

Solution 2

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. 

Solution 3

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.

Solution 4

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;
}

Solution 5

javadocs show that the parse method is overloaded.

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

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Comments

[Christophe Roussy]

Also note that javax.xml.parsers.DocumentBuilder.parse(string) assumes the string is a uri (terrible...)

[palantus]

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

[bendin]

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?

[sattu]

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

[Alexander Malakhov]

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

[nkuebelbeck]

thanks much, saved me bunch lines of code, i was converting it back to text but I knew there was a better way!

[Dejell]

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

[Daniel Eisenreich]

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

[john ktejik]

For me, parse() takes InputStream, not InputSource

[John LaBarge]

Why is everything in Java so gross? Seriously?