CODEWITHSUNDEEP
javaxmlxpath
jeremyjjbrown
jeremyjjbrown

Reputation: 8009

Java xpath to return an entire element as string

I need to use java xpath to return by id an xml element as a string.

given...

<svg>
    <g id="Background">
    </g>
    <g id="Outline">
        <polygon fill="none" stroke="#000000" stroke-linecap="round" stroke-linejoin="round"     stroke-miterlimit="10" points=" 119.813,57.875 119.188,57.87" />
    </g>
    <g id="Base_Colour" transform="matrix(0.25 0 0 0.25 0 0)">
        <path fill="#ADB1AF" d="M112.25,208l-8,20.25l-0.5-1.75l0.75-0.5v-1.5l0.75-0.5v-1.5L106,222v-1.5l0.75-0.5v-1.5l0.75-0.5v-1.5"/>
        <path fill="#625595" d="M112.25,208l5.25-14.5l30-30.25l2.25-1.5l41.5-20.5l49.75-9.5h4.25l49,3l48.75"/>
    </g>
</svg>

the value returned needs to be...

<g id="Outline">
    <polygon fill="none" stroke="#000000" stroke-linecap="round" stroke-linejoin="round"     stroke-miterlimit="10" points=" 119.813,57.875 119.188,57.87" />
</g>

I have googled extensively and nothing I have tried has been able to return the whole element. Xpath is desired because I want to query g tags at any level by id.

Upvotes: 7

Views: 5026

Answers (5)

Aamir
Aamir

Reputation: 725

Sometime you have to do it without an xml document in Java; and I find below code very use full

import java.io.IOException;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

String responseMsg = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><YourMessage><MyTag>MyTagValue</MyTag></YourMessage>";
String expressionToExract = "/YourMessage/MyTag";
String xmlNodeWithData = xpathTester.getXmlNode(responseMsg, expressionToExract);
//above xmlNodeWithData will have this value '<MyTag>MyTagValue</MyTag>'

private String getXmlNode(String resultMsg, String expression)
        throws ParserConfigurationException, SAXException, IOException, XPathExpressionException {
    String xmlNodeWithData="";
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    InputSource is = null;
    StringReader sr = null;
    sr = new StringReader(resultMsg);
    is = new InputSource(sr);

    Document doc = builder.parse(is);
    XPathFactory xPathfactory = XPathFactory.newInstance();
    XPath xpath = xPathfactory.newXPath();
    XPathExpression expr = xpath.compile(expression);

    Node node = (Node)expr.evaluate(doc, XPathConstants.NODE);      
    xmlNodeWithData += "<" + node.getNodeName() + ">";
    NodeList nodeList = node.getChildNodes();

    for (int nodeIndex=0; nodeIndex < nodeList.getLength(); nodeIndex++) {
        Node nodeChild = nodeList.item(nodeIndex);          
        if (nodeChild.getNodeName().contains("#text")) {
            xmlNodeWithData += nodeChild.getTextContent();
            continue;
        }
        xmlNodeWithData += "<" + nodeChild.getNodeName() + ">";         
        xmlNodeWithData += nodeChild.getTextContent();
        xmlNodeWithData += "</" + nodeChild.getNodeName() + ">";
    }
    xmlNodeWithData += "</" + node.getNodeName() + ">";
    if (sr != null) {
        sr.close();
    }
    return xmlNodeWithData;
}

Upvotes: 0

lidermin
lidermin

Reputation: 2832

I solved my problem with this code:

public static String getOuterXml(Node node)
    throws TransformerConfigurationException, TransformerException {
    Transformer transformer = TransformerFactory.newInstance().newTransformer();
    transformer.setOutputProperty("omit-xml-declaration", "yes");

    StringWriter writer = new StringWriter();
    transformer.transform(new DOMSource(node), new StreamResult(writer));
    return writer.toString();         
}

Credits to: chick.Net

Upvotes: 0

jeremyjjbrown
jeremyjjbrown

Reputation: 8009

The solution I found was to get the org.w3c.dom.Node with xpath (DOM would work too). Then I created a javax.xml.transform.dom.DOMSource from the node and transformed that to a string with javax.xml.transform.TransformerFactory.

Node node = // the node you want to serialize
xmlOutput = new StreamResult(new StringWriter());
transformer = TransformerFactory.newInstance().newTransformer();
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
transformer.transform(new DOMSource(node), xmlOutput);
String nodeAsAString = xmlOutput.getWriter().toString();

This is easily factored into a class for reuse. Unfortunately, the is no .OuterXml property in Java as there is in .NET. All you .NETer's can smirk now.

Upvotes: 10

Dimitre Novatchev
Dimitre Novatchev

Reputation: 243579

I don't know about Java, but in the .NET world one will use:

doc.DocumentElement.SelectSingleNode("/*/g[@id='Outline']").OuterXml

Upvotes: -1

bmargulies
bmargulies

Reputation: 100161

No xpath will return a string containing XML syntax, ever.

Upvotes: 1

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