XML 实用工具类

package com.elink.util;

/*
 * <p>Company: 凌科软件 www.elingke.com </p>
 * @author liubaojun
 * @version 1.0
 * Created on 2004-11-29
 * 来源于 elinkBSP 部分源代码
 */
 
import java.io.*;
import java.util.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

import org.w3c.dom.*;
import org.xml.sax.*;

public class XmlUtil
{
 public static synchronized Document newDocument()
 {
  Document doc = null;
  try
  {
   DocumentBuilder db = DocumentBuilderFactory.newInstance().
    newDocumentBuilder();
   doc = db.newDocument();
  }
  catch (Exception e)
  {
   LogUtil.logException( e );
  }
  return doc;
 }

 public static synchronized Element createRootElement()
 {
  Element rootElement = null;
  try
  {
   DocumentBuilder db = DocumentBuilderFactory.newInstance().
    newDocumentBuilder();
   Document doc = db.newDocument();
   rootElement = doc.getDocumentElement();
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
  return rootElement;
 }

 public static synchronized Element getRootElement(String fileName)
 {
  if (fileName == null || fileName.length() == 0)
  {
   return null;
  }
  try
  {
   Element rootElement = null;
   FileInputStream fis = new FileInputStream(fileName);
   rootElement = getRootElement(fis);
   fis.close();
   return rootElement;
  }
  catch (Exception e)
  {
   return null;
  }
 }

 public static synchronized Element getRootElement(InputStream is)
 {
  if (is == null)
  {
   return null;
  }
  Element rootElement = null;
  try
  {
   DocumentBuilder db = DocumentBuilderFactory.newInstance().
    newDocumentBuilder();
   Document doc = db.parse(is);
   rootElement = doc.getDocumentElement();
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
  return rootElement;
 }
 
 public static synchronized Element getRootElement(InputSource is)
 {
  if (is == null)
  {
   return null;
  }
  Element rootElement = null;
  try
  {
   DocumentBuilder db = DocumentBuilderFactory.newInstance().
    newDocumentBuilder();
   Document doc = db.parse(is);
   rootElement = doc.getDocumentElement();
  }
  catch (Exception e)
  {
   e.printStackTrace();
  }
  return rootElement;
 }

 public static synchronized Element[] getChildElements(Element element)
 {
  if (element == null)
  {
   return null;
  }
  Vector childs = new Vector();
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Element)
   {
    childs.add( (Element)node);
   }
  }
  Element[] elmt = new Element[childs.size()];
  childs.toArray(elmt);
  return elmt;
 }

 public static synchronized Element[] getChildElements(Element element,
  String childName)
 {
  if (element == null || childName == null || childName.length() == 0)
  {
   return null;
  }
  Vector childs = new Vector();
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Element)
   {
    if (node.getNodeName().equals(childName))
    {
     childs.add( (Element)node);
    }
   }
  }
  Element[] elmt = new Element[childs.size()];
  childs.toArray(elmt);
  return elmt;
 }

 public static synchronized Node[] getChildNodes(Node node)
 {
  if (node == null)
  {
   return null;
  }
  Vector childs = new Vector();
  for (Node n = node.getFirstChild(); n != null;
    n = n.getNextSibling())
  {
   childs.add( (Element)n);
  }
  Node[] childNodes = new Element[childs.size()];
  childs.toArray(childNodes);
  return childNodes;
 }

 public static synchronized Element getChildElement(Element element,
            String childName)
 {
  if (element == null || childName == null || childName.length() == 0)
  {
   return null;
  }
  Element childs = null;
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Element)
   {
    if (node.getNodeName().equals(childName))
    {
     childs = (Element)node;
     break;
    }
   }
  }
  return childs;
 }

 public static synchronized Element getChildElement(Element element)
 {
  if (element == null)
  {
   return null;
  }
  Element childs = null;
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Element)
   {
    childs = (Element)node;
    break;
   }
  }
  return childs;
 }

 public static synchronized String[] getElenentValues(Element element)
 {
  if (element == null)
  {
   return null;
  }
  Vector childs = new Vector();
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Text)
   {
    childs.add(node.getNodeValue());
   }
  }
  String[] values = new String[childs.size()];
  childs.toArray(values);
  return values;
 }

 public static synchronized String getElenentValue(Element element)
 {
  if (element == null)
  {
   return null;
  }
  String retnStr = null;
  for (Node node = element.getFirstChild(); node != null;
    node = node.getNextSibling())
  {
   if (node instanceof Text)
   {
    String str = node.getNodeValue();
    if (str == null || str.length() == 0
     || str.trim().length() == 0)
    {
     continue;
    }
    else
    {
     retnStr = str;
     break;
    }
   }
  }
  return retnStr;
 }

 public static synchronized Element findElementByName(Element e, String name)
 {
  if (e == null || name == null || name.length() == 0)
  {
   return null;
  }
  String nodename = null;
  Element[] childs = getChildElements(e);
  for (int i = 0; i < childs.length; i++)
  {
   nodename = childs[i].getNodeName();
   if (name.equals(nodename))
   {
    return childs[i];
   }
  }
  for (int i = 0; i < childs.length; i++)
  {
   Element retn = findElementByName(childs[i], name);
   if (retn != null)
   {
    return retn;
   }
  }
  return null;
 }
 public static synchronized Element findElementByAttr(Element e, String attrName,
              String attrVal)
 {
  return findElementByAttr( e, attrName, attrVal, true );
 }

 public static synchronized Element findElementByAttr(Element e, String attrName,
              String attrVal, boolean dept)
 {
  if (e == null || attrName == null || attrName.length() == 0
   || attrVal == null || attrVal.length() == 0)
  {
   return null;
  }
  String tmpValue = null;
  Element[] childs = getChildElements(e);
  for (int i = 0; i < childs.length; i++)
  {
   tmpValue = childs[i].getAttribute(attrName);
   if (attrVal.equals(tmpValue))
   {
    return childs[i];
   }
  }
  if( dept )
  {
   for (int i = 0; i < childs.length; i++)
   {
    Element retn = findElementByAttr(childs[i], attrName, attrVal);
    if (retn != null)
    {
     return retn;
    }
   }
  }
  return null;
 }

 public static synchronized String formatXml(Element e)
 {
  return formatXml(e, 0);
 }

 /**
  * 格式化XML输出串.
  */
 public static synchronized String formatXml(Element e, int indent)
 {
  indent++;
  for (Node n = e.getFirstChild(); n != null; n = n.getNextSibling())
  {
   appendIndent(e, n, indent);
   if (!n.getNodeName().equals("#text"))
   {
    formatXml( (Element)n, indent);
   }
  }
  indent--;
  appendIndent(e, indent);
  return e.toString();
 }

 /**
  * 在指定的节点前插入格式表示.
  */
 private static synchronized void appendIndent(Element e, Node pos, int indent)
 {
  Document doc = e.getOwnerDocument();
  if (indent == 0)
  {
   e.insertBefore(doc.createTextNode("\n"), pos);
  }
  for (int i = 0; i < indent; i++)
  {
   if (i == 0)
   {
    e.insertBefore(doc.createTextNode("\n\t"), pos);
   }
   else
   {
    e.insertBefore(doc.createTextNode("\t"), pos);
   }
  }
 }

 /**
  * 追加格式表示.
  */
 private static synchronized void appendIndent(Element e, int indent)
 {
  Document doc = e.getOwnerDocument();
  if (indent == 0)
  {
   e.appendChild(doc.createTextNode("\n"));
  }
  for (int i = 0; i < indent; i++)
  {
   if (i == 0)
   {
    e.appendChild(doc.createTextNode("\n\t"));
   }
   else
   {
    e.appendChild(doc.createTextNode("\t"));
   }
  }
 }

 public static synchronized void setAttribute(Element e, String name, String value)
 {
  if (e == null || name == null || name.length() == 0 || value == null
   || value.length() == 0)
   return;
  else
   e.setAttribute( name, value );
 }

 public static synchronized String getAttribute(Element e, String name)
 {
  return getAttribute( e, name, null );
 }
 public static synchronized String getAttribute(Element e, String name, String defval)
 {
  if( e == null || name == null || name.length()== 0 )
   return defval;
  else
   return e.getAttribute(name);
 }
 
 public void transformerWrite( Element doc, String filename ) throws Exception
 {
  DOMSource doms = new DOMSource( doc );
  File f = new File( filename );
  StreamResult sr = new StreamResult( f );
  transformerWrite( doms, sr );
 }
 
 public void transformerWrite( Element doc, File file ) throws Exception
 {
  DOMSource doms = new DOMSource( doc );
  StreamResult sr = new StreamResult( file );
  transformerWrite( doms, sr );
 }
 
 public void transformerWrite( Element doc, OutputStream outstream ) throws Exception
 {
  DOMSource doms = new DOMSource( doc );
  StreamResult sr = new StreamResult( outstream );
  transformerWrite( doms, sr );
 }
 
 public void transformerWrite( Element doc, Writer outwriter ) throws Exception
 {
  DOMSource doms = new DOMSource( doc );
  StreamResult sr = new StreamResult( outwriter );
  transformerWrite( doms, sr );
 }
 
 public void transformerWrite( DOMSource doms, StreamResult sr ) throws Exception
 {
  TransformerFactory tf = TransformerFactory.newInstance();
  Transformer t = tf.newTransformer();
  t.setOutputProperty( OutputKeys.ENCODING, "GBK" );
  t.transform( doms, sr );
 }
}

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