XMLUnit Java User’s Guide

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5.4Configuration Options

When using XpathEngine directly you are responsible for creating the DOM document yourself. If you use the convenience methods of XMLTestCase or XMLAssert you have several options to specify the input; XMLUnit will use the control or test parser that has been configured (see Section 2.4.1) to create a DOM document from the given piece of XML in that case - using the configured EntityResolver(s) (see Section 2.4.2) if any.

If JAXP 1.3 is not available, SimpleXpathEngine will use the configured JAXP XSLT transformer (see Section 2.4.1) under the covers.

When using JAXP 1.3 you can chose the actual XPathFactory implementation using XMLUnit.setXPathFactory.

It is possible to establish a global NamespaceContext with the help of the XMLUnit.setXpathNamespaceContext method. Any XpathEngine created by XMLUnit.newXpathEngine will automatically use the given context. Note that the JUnit 3 convenience methods use XMLUnit.newXpathEngine implicitly and will thus use the configured Namespace Context.

6 DOM Tree Walking

Sometimes it is easier to test a piece of XML’s validity by traversing the whole document node by node and test each node individually. Maybe there is no control XML to validate against or the expected value of an element’s content has to be calculated. There may be several reasons.

XMLUnit supports this approach of testing via the NodeTest class. In order to use it, you need a DOM implementation that generates Document instances that implement the optional org.w3c.traversal.DocumentTraversal interface, which is not part of JAXP’s standardized DOM support.

6.1 DocumentTraversal

As of the release of XMLUnit 1.1 the Document instances created by most parsers implement DocumentTraversal, this includes but is not limited to Apache Xerces, the parser shipping with Sun’s JDK 5 and later or GNU JAXP. One notable exception is Apache Crimson, which also means the parser shipping with Sun’s JDK 1.4 does not support traversal; you need to specify a different parser when using JDK 1.4 (see Section 2.4.1).

You can test whether your XML parser supports DocumentTraversal by invoking org.w3c.dom.DOMImplementat ion’s hasFeature method with the feature "Traversal".

6.2 NodeTest

The NodeTest is instantiated with a piece of XML to traverse. It offers two performTest methods:

/**

*Does this NodeTest pass using the specified NodeTester instance?

*@param tester

*@param singleNodeType note <code>Node.ATTRIBUTE_NODE</code> is not

*exposed by the DocumentTraversal node iterator unless the root node

*is itself an attribute - so a NodeTester that needs to test attributes

*should obtain those attributes from <code>Node.ELEMENT_NODE</code>

*nodes

*@exception NodeTestException if test fails

*/

public void performTest(NodeTester tester, short singleNodeType);

/**

*Does this NodeTest pass using the specified NodeTester instance?

*@param tester

*@param nodeTypes note <code>Node.ATTRIBUTE_NODE</code> is not

*exposed by the DocumentTraversal node iterator unless the root node