xml - finding node values DOM with in Java

Question

How can I get the value of specific nodes in Java from XML.

I have structure like what you see bellow and I want to get the values of userFileds(2,N.A. for the first one and 1 for the last one(it is part of real xml data. the number of elements are more):

<element class="AufOrgKombination" hash="AOK_1414931143186_52">
<field name="layer">4</field><field name="name">Function </field>
<field name="description">des</field>
<userField hash="USERFIELD_1415779871581_0">2.0</userField>
<userField hash="USERFIELD_1415386348389_3">N.A.</userField>
</element>
<element class="AufOrgKombination" hash="AOK_1414931143186_23">
<field name="layer">4</field><field name="name">Function 2 </field>
<field name="description">des</field>
<userField hash="USERFIELD_1415779871581_0">1</userField>
</element>

Answer 1

You should consider not to use the XPath API, but a library that handles it for you (Disclosure: I'm affiliated with that project). You probably want to reflect the XML structure somehow to your object structure. There are some difficulties to overcome (Namespaces, default namespaces, type conversion, mapping to Java objects, ...). One possible solution using the suggested library:

public class Demo {

public interface Projection {
    interface Element {
        @XBRead("./userField")
        List<String> getUserFieldValues();
    }

    @XBRead("//element")
    List<Projection.Element> getElements();
}

public static void main(final String[] args) throws IOException {
    Projection projection = new XBProjector().io().url("resource://data.xml").read(Projection.class);
    for (Projection.Element element : projection.getElements()) {
        for (String userField : element.getUserFieldValues()) {
            System.out.println(userField);
            }
        }
    }
}

This program prints out:

2.0
N.A.
1