<path id="validation.class.path">
		<fileset dir="${eclipse.home}/plugins">
			 <include name="**/*.jar"/>
		</fileset>
	</path>

	<taskdef name="wsdl.validate" classname="org.eclipse.wst.wsdl.validation.internal.ui.ant.WSDLValidate">
		<classpath refid="validation.class.path" />
	</taskdef>


	<target name="validate.wsdl">
		<property name="wsdl.file" value="${wsdl.name}" />

		<echo message="Validate WSDL: ${wsdl.file}"/>
		
		<wsdl.validate file="${wsdl.file}"/>
	</target>

...
URI uri = wsdlpath.toFile().toURI();
WSDLValidator validator = WSDLValidator.getInstance();
IValidationReport report = validator.validate(uri.toString());
...