Question: I have the following XML:

```
     <ConfigGroup Name="Replication">
        <ValueInteger Name="ResponseTimeout">10</ValueInteger>
        <ValueInteger Name="PingTimeout">2</ValueInteger>
        <ValueInteger Name="ConnectionTimeout">10</ValueInteger>
        <ConfigGroup Name="Pool">
            <ConfigGroup Name="1">
                <ValueString Encrypted="false" Name="Host">10.20.30.40</ValueString>
                <ValueInteger Name="CacheReplicationPort">8899</ValueInteger>
                <ValueInteger Name="RadiusPort">12050</ValueInteger>
                <ValueInteger Name="OtherPort">4868</ValueInteger>
            </ConfigGroup>
            <ConfigGroup Name="2">
                <ValueString Encrypted="false" Name="Host">10.20.30.50</ValueString>
                <ValueInteger Name="CacheReplicationPort">8899</ValueInteger>
                <ValueInteger Name="RadiusPort">12050</ValueInteger>
                <ValueInteger Name="OtherPort">4868</ValueInteger>
            </ConfigGroup>
        </ConfigGroup>
     </ConfigGroup>

```

I just wondering what is the simplest way to parse this XML in Java - I want the value from the two host elements (e.g. 10.20.30.40 and 10.20.30.50). Note there may be more than two pool entries (or none at all).

I'm having trouble finding a simple example of how to use the various XML parsers for Java.

Any help is much appreciated.

Thanks!

Answer: 
The simplest way to search for what you are looking for, would be XPath.

```
try {

    //Load the XML File
    DocumentBuilderFactory domFactory = DocumentBuilderFactory.newInstance();
    domFactory.setNamespaceAware(true);
    DocumentBuilder builder = domFactory.newDocumentBuilder();
    Document configuration = builder.parse("configs.xml");

    //Create an XPath expression
    XPathFactory xpathFactory = XPathFactory.newInstance();
    XPath xpath = xpathFactory.newXPath();
    XPathExpression expr = xpath.compile("//ConfigGroup/ValueString[@Name='Host']/text()");

    //Execute the XPath query
    Object result = expr.evaluate(configuration, XPathConstants.NODESET);
    NodeList nodes = (NodeList) result;

    //Parse the results
    for (int i = 0; i < nodes.getLength(); i++) {
        System.out.println(nodes.item(i).getNodeValue()); 
    }
} catch (ParserConfigurationException e) {
    System.out.println("Bad parser configuration");
    e.printStackTrace();
} catch (SAXException e) {
    System.out.println("SAX error loading the file.");
    e.printStackTrace();
} catch (XPathExpressionException e) {
    System.out.println("Bad XPath Expression");
    e.printStackTrace();
} catch (IOException e) {
    System.out.println("IO Error reading the file.");
    e.printStackTrace();
}

```

The XPath expression 

```
"//ConfigGroup/ValueString[@Name='Host']/text()"

```

looks for ConfigGroup elements anywhere in your XML, then finds ValueString elements within the ConfigGroup elements, that have a Name attribute with the value "Host". @Name=Host is like a filter for elements with the name ValueString. And text() at the end, returns the text node of the selected elements.
Java XPath API allows to do it easily. The following xpath expression 

```
//ValueString[@Name='Host']

```

should match what you want. Here is how to use it with the API :

```
Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(yourXml.getBytes());
XPath xpath = XPathFactory.newInstance().newXPath();
NodeList nodeList = (NodeList) xpath.compile("//ValueString[@Name='Host']").evaluate(doc, XPathConstants.NODESET);
for (int i = 0; i < nodeList.getLength(); i++) {
  String ip = ((Element) nodeList.item(i)).getTextContent();
  // do something with your ip
}

```