DeusNexXmlUtils.java

package fi.otavanopisto.muikku.plugins.dnm.parser;

import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class DeusNexXmlUtils {

  public static Double getChildValueDouble(Element parent, String name) throws XPathExpressionException {
    String childValue = getChildValue(parent, name);
    if (StringUtils.isNotBlank(childValue)) {
      return NumberUtils.createDouble(childValue);
    }

    return null;
  }

  public static int getChildValueInt(Element parent, String name) throws XPathExpressionException {
    Integer i = getChildValueInteger(parent, name);
    return i == null ? 0 : i.intValue();
  }

  public static Boolean getChildValueBoolean(Element parent, String name) throws XPathExpressionException {
    String childValue = getChildValue(parent, name);
    if (StringUtils.isNotBlank(childValue)) {
      return "true".equals(childValue);
    }

    return null;
  }

  public static Integer getChildValueInteger(Element parent, String name) throws XPathExpressionException {
    String childValue = getChildValue(parent, name);
    if (StringUtils.isNotBlank(childValue)) {
      return NumberUtils.createInteger(childValue);
    }

    return null;
  }

  public static Long getChildValueLong(Element parent, String name) throws XPathExpressionException {
    String childValue = getChildValue(parent, name);
    if (StringUtils.isNotBlank(childValue)) {
      return NumberUtils.createLong(childValue);
    }

    return null;
  }

  public static String getChildValue(Element parent, String name) throws XPathExpressionException {
    Node node = findNodeByXPath(parent, name);
    if (node instanceof Element) {
      return ((Element) node).getTextContent();
    }

    return null;
  }

  public static List<Element> getElementsByXPath(Element parent, String name) throws XPathExpressionException {
    List<Element> result = new ArrayList<>();
    for (Node node : getNodesByXPath(parent, name)) {
      if (node instanceof Element) {
        result.add((Element) node);
      }
    }

    return result;
  }

  public static List<Node> getNodesByXPath(Element parent, String name) throws XPathExpressionException {
    List<Node> result = new ArrayList<>();

    NodeList nodeList = findNodesByXPath(parent, name);
    for (int i = 0, l = nodeList.getLength(); i < l; i++) {
      result.add(nodeList.item(i));
    }

    return result;
  }

  public static Node findNodeByXPath(Node contextNode, String expression) throws XPathExpressionException {
    return (Node) XPathFactory.newInstance().newXPath().evaluate(expression, contextNode, XPathConstants.NODE);
  }

  public static NodeList findNodesByXPath(Node contextNode, String expression) throws XPathExpressionException {
    return (NodeList) XPathFactory.newInstance().newXPath().evaluate(expression, contextNode, XPathConstants.NODESET);
  }

  public static String serializeElement(Element element, boolean omitXmlDeclaration, boolean indent, String method) throws TransformerException {
    TransformerFactory transformerFactory = TransformerFactory.newInstance();
    Transformer transformer = transformerFactory.newTransformer();
    transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
    transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, omitXmlDeclaration ? "yes" : "no");
    transformer.setOutputProperty(OutputKeys.METHOD, method);
    transformer.setOutputProperty(OutputKeys.INDENT, indent ? "yes" : "no");

    StringWriter writer = new StringWriter();
    transformer.transform(new DOMSource(element), new StreamResult(writer));
    return writer.getBuffer().toString();
  }

  public static DocumentBuilder createDocumentBuilder() throws DeusNexInternalException {
    DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();
    builderFactory.setNamespaceAware(false);
    builderFactory.setValidating(false);
    DocumentBuilder builder;

    try {
      builderFactory.setFeature("http://xml.org/sax/features/namespaces", false);
      builderFactory.setFeature("http://xml.org/sax/features/validation", false);
      builderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-dtd-grammar", false);
      builderFactory.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
      builder = builderFactory.newDocumentBuilder();
    } catch (ParserConfigurationException e) {
      throw new DeusNexInternalException("Invalid XML Parser configuration", e);
    }
    return builder;
  }

}