domutils.java

编写rest实例 rest分布式框架在app中的应用

package com.jeffhanson.atompub;

import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Iterator;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import com.jeffhanson.atompub.introspect.ServiceDocumentException;

public class DOMUtils
{
  private static TransformerFactory transformerFactory = null;

  private static Transformer transformer = null;

  public static Transformer getTransformer()
      throws TransformerConfigurationException
  {
    if (transformerFactory == null)
    {
      transformerFactory = TransformerFactory.newInstance();
    }

    if (transformer == null)
    {
      transformer = transformerFactory.newTransformer();
    }

    return transformer;
  }

  public static void write(Node node, OutputStream out)
      throws ServiceDocumentException
  {
    javax.xml.transform.dom.DOMSource domSource =
      new javax.xml.transform.dom.DOMSource(node);

    try
    {
      DOMUtils.getTransformer().transform(domSource,
                                          new StreamResult(out));
    }
    catch (TransformerException e)
    {
      e.printStackTrace();
      throw new ServiceDocumentException(e);
    }
  }

  /**
   * 
   * @param doc
   * @param elementTagName
   * @return Node
   */
  public static Node getDOMNode(Document doc,
                                String elementTagName)
  {
    org.w3c.dom.NodeList nodeList = doc.getElementsByTagName(elementTagName);
    if (nodeList != null && nodeList.getLength() > 0)
    {
      return nodeList.item(0);
    }

    return null;
  }

  /**
   * 
   * @param parentNode
   * @param childNodeTagName
   * @return Node
   */
  public static Node getChildNode(Node parentNode,
                                  String childNodeTagName)
  {
    NodeList childNodes = parentNode.getChildNodes();
    if (childNodes != null && childNodes.getLength() > 0)
    {
      for (int i = 0; i < childNodes.getLength(); i++)
      {
        Node node = childNodes.item(i);
        if (node.getNodeName().equalsIgnoreCase(childNodeTagName))
        {
          return node;
        }
      }
    }

    return null;
  }

  /**
   * 
   * @param parentNode
   * @param childNodeTagName
   * @return Iterator<Node>
   */
  public static Iterator<Node> getChildNodes(Node parentNode,
                                             String childNodeTagName)
  {
    ArrayList<Node> matchingNodes = new ArrayList<Node>();
    NodeList childNodes = parentNode.getChildNodes();
    if (childNodes != null && childNodes.getLength() > 0)
    {
      for (int i = 0; i < childNodes.getLength(); i++)
      {
        Node node = childNodes.item(i);
        String nodeName = node.getNodeName();
        if (nodeName.equalsIgnoreCase(childNodeTagName))
        {
          matchingNodes.add(node);
        }
      }
    }

    return matchingNodes.iterator();
  }

  /**
   * 
   * @param parentNode
   * @param childNodeTagName
   * @param attrValue
   * @return Node
   */
  public static Node getChildNodeWithAttr(Node parentNode,
                                          String childNodeTagName,
                                          String attrName,
                                          String attrValue)
  {
    NodeList childNodes = parentNode.getChildNodes();
    if (childNodes != null && childNodes.getLength() > 0)
    {
      for (int i = 0; i < childNodes.getLength(); i++)
      {
        Node node = childNodes.item(i);
        String nodeName = node.getNodeName();
        if (nodeName.equalsIgnoreCase(childNodeTagName))
        {
          org.w3c.dom.NamedNodeMap nodeMap = node.getAttributes();
          if (nodeMap != null)
          {
            org.w3c.dom.Node attrNode = nodeMap.getNamedItem(attrName);
            if (attrNode != null && attrNode.getNodeValue().equalsIgnoreCase(attrValue))
            {
              return node;
            }
          }
        }
      }
    }

    return null;
  }

  /**
   * 
   * @param doc
   * @param elementTagName
   * @param attrValue
   * @return Node
   */
  public static Node getDOMNodeWithAttr(Document doc,
                                        String elementTagName,
                                        String attrName,
                                        String attrValue)
  {
    org.w3c.dom.NodeList nodeList = doc.getElementsByTagName(elementTagName);
    if (nodeList != null && nodeList.getLength() > 0)
    {
      for (int i = 0; i < nodeList.getLength(); i++)
      {
        Node node = nodeList.item(i);
        org.w3c.dom.NamedNodeMap nodeMap = node.getAttributes();
        if (nodeMap != null)
        {
          org.w3c.dom.Node attrNode = nodeMap.getNamedItem(attrName);
          if (attrNode != null && attrNode.getNodeValue().equalsIgnoreCase(attrValue))
          {
            return node;
          }
        }
      }
    }

    return null;
  }

  /**
   * 
   * @param doc
   * @param elementTagName
   * @param attrName
   * @return String
   */
  public static String getDOMNodeAttributeValue(Document doc,
                                                String elementTagName,
                                                String attrName)
      throws DOMUtilsException
  {
    org.w3c.dom.Node node = getDOMNode(doc, elementTagName);
    if (node == null)
    {
      throw new DOMUtilsException("Could not find an element with tag [" + elementTagName + "]");
    }

    org.w3c.dom.NamedNodeMap nodeMap = node.getAttributes();
    if (nodeMap != null)
    {
      org.w3c.dom.Node attrNode = nodeMap.getNamedItem(attrName);
      if (attrNode != null)
      {
        return attrNode.getTextContent();
      }
    }

    return "";
  }

  /**
   * 
   * @param node
   * @param attrName
   * @return String
   */
  public static String getDOMNodeAttributeValue(Node node,
                                                String attrName)
  {
    org.w3c.dom.NamedNodeMap nodeMap = node.getAttributes();
    if (nodeMap != null)
    {
      org.w3c.dom.Node attrNode = nodeMap.getNamedItem(attrName);
      if (attrNode != null)
      {
        return attrNode.getTextContent();
      }
    }

    return "";
  }
}