package org.apache.turbine.util;
   
   /* ====================================================================
    * The Apache Software License, Version 1.1
    *
    * Copyright (c) 2001-2003 The Apache Software Foundation.  All rights
    * reserved.
    *
    * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org/)."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache" and "Apache Software Foundation" and
   *    "Apache Turbine" must not be used to endorse or promote products
   *    derived from this software without prior written permission. For
   *    written permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    "Apache Turbine", nor may "Apache" appear in their name, without
   *    prior written permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   */
  
  import java.io.BufferedInputStream;
  import java.io.BufferedOutputStream;
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.io.Serializable;
  import java.util.Enumeration;
  import java.util.Hashtable;
  import java.util.List;
  
  /***
   * This is where common Object manipulation routines should go.
   *
   * @author <a href="mailto:nissim@nksystems.com">Nissim Karpenstein</a>
   * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
   * @version $Id: ObjectUtils.java,v 1.7 2004/03/28 17:36:20 epugh Exp $
   */
  public abstract class ObjectUtils
  {
      /***
       * Returns a default value if the object passed is null.
       *
       * @param o The object to test.
       * @param dflt The default value to return.
       * @return The object o if it is not null, dflt otherwise.
       * @deprecated Use org.apache.commons.lang.ObjectUtils.defaultIfNull()
       */
      public static Object isNull(Object o, Object dflt)
      {
  		return org.apache.commons.lang.ObjectUtils.defaultIfNull(o,dflt);
      }
  
      /***
       * Adds an object to a vector, making sure the object is in the
       * vector only once.
       *
       * @param v The vector.
       * @param o The object.
       * @deprecated No replacement
       */
      public static void addOnce(List l, Object o)
     {
         if (!l.contains(o))
         {
             l.add(o);
         }
     }
 
     /***
      * Converts a hashtable to a byte array for storage/serialization.
      *
      * @param hash The Hashtable to convert.
      *
      * @return A byte[] with the converted Hashtable.
      *
      * @exception Exception A generic exception.
      */
     public static byte[] serializeHashtable(Hashtable hash)
         throws Exception
     {
         Hashtable saveData = new Hashtable(hash.size());
         String key = null;
         Object value = null;
         byte[] byteArray = null;
 
         Enumeration keys = hash.keys();
 
         while (keys.hasMoreElements())
         {
             key = (String) keys.nextElement();
             value = hash.get(key);
             if (value instanceof Serializable)
             {
                 saveData.put (key, value);
             }
         }
 
         ByteArrayOutputStream baos = null;
         BufferedOutputStream bos = null;
         ObjectOutputStream out = null;
         try
         {
             // These objects are closed in the finally.
             baos = new ByteArrayOutputStream();
             bos  = new BufferedOutputStream(baos);
             out  = new ObjectOutputStream(bos);
 
             out.writeObject(saveData);
             out.flush();
             bos.flush();
 
             byteArray = baos.toByteArray();
         }
         finally
         {
             if (out != null)
             {
                 out.close();
             }
             if (bos != null)
             {
                 bos.close();
             }
             if (baos != null)
             {
                 baos.close();
             }
         }
         return byteArray;
     }
 
     /***
      * Deserializes a single object from an array of bytes.
      *
      * @param objectData The serialized object.
      *
      * @return The deserialized object, or <code>null</code> on failure.
      */
     public static Object deserialize(byte[] objectData)
     {
         Object object = null;
 
         if (objectData != null)
         {
             // These streams are closed in finally.
             ObjectInputStream in = null;
             ByteArrayInputStream bin = new ByteArrayInputStream(objectData);
             BufferedInputStream bufin = new BufferedInputStream(bin);
             
             try
             {
                 in = new ObjectInputStream(bufin);
 
                 // If objectData has not been initialized, an
                 // exception will occur.
                 object = in.readObject();
             }
             catch (Exception e)
             {
             }
             finally
             {
                 try
                 {
                     if (in != null)
                     {
                         in.close();
                     }
                     if (bufin != null)
                     {
                         bufin.close();
                     }
                     if (bin != null)
                     {
                         bin.close();
                     }
                 }
                 catch (IOException e)
                 {
                 }
             }
         }
         return object;
     }
 
     /***
      * Compares two Objects, returns true if their values are the
      * same.  It checks for null values prior to an o1.equals(o2)
      * check
      *
      * @param o1 The first object.
      * @param o2 The second object.
      * @return True if the values of both xstrings are the same.
      * @deprecated Use org.apache.commons.lang.ObjectUtils.equals()
      */
     public static boolean equals(Object o1, Object o2)
     {
 		return org.apache.commons.lang.ObjectUtils.equals(o1,o2);
     }
 
     /***
      * Nice method for adding data to a Hashtable in such a way
      * as to not get NPE's. The point being that if the
      * value is null, Hashtable.put() will throw an exception.
      * That blows in the case of this class cause you may want to
      * essentially treat put("Not Null", null ) == put("Not Null", "")
      * We will still throw a NPE if the key is null cause that should
      * never happen.
      * @deprecated No replacement
      */
     public static final void safeAddToHashtable(Hashtable hash, Object key,
                                                 Object value)
             throws NullPointerException
     {
         if (value == null)
         {
             hash.put(key, "");
         }
         else
         {
             hash.put(key, value);
         }
     }
 }