Java通过XPath获取XML文件中符合特定条件的节点

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
import org.w3c.dom.Element;
String value = new String("test");
XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "//ElementName[@moduleName='" + value + "']";
Element element = null;
try {
 element = (Element) xpath.evaluate(expression, document,
  XPathConstants.NODE);
} catch (XPathExpressionException e) {
 e.printStackTrace();
}