在JAXB中是否可以过滤出值为elements的子元素？

import javax.xml.bind.Unmarshaller;
import javax.xml.bind.Unmarshaller.Listener;
import javax.xml.bind.UnmarshallingContext;
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;

public class MyUnmarshalListener extends Listener {
    @Override
    public void beforeUnmarshal(Object target, Object parent) {
        if (target instanceof JAXBElement) {
            JAXBElement<?> element = (JAXBElement<?>) target;
            if (element.getValue() instanceof MyElementType) {
                MyElementType value = (MyElementType) element.getValue();
                if (value.getElements() != null) {
                    // 过滤出值为elements的子元素
                    try {
                        XPathFactory xPathFactory = XPathFactory.newInstance();
                        XPath xPath = xPathFactory.newXPath();
                        XPathExpression expression = xPath.compile("//elements");
                        Object result = expression.evaluate(value.getElements(), XPathConstants.NODESET);
                        // 处理过滤结果
                        // ...
                    } catch (XPathExpressionException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}