jvanzyl 01/08/08 06:20:56 Added: util/src/java/org/apache/commons/util ObjectUtils.java Log: - moving another turbine util Revision Changes Path 1.1 jakarta-commons-sandbox/util/src/java/org/apache/commons/util/ObjectUtils.java Index: ObjectUtils.java =================================================================== package org.apache.commons.util; /* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 2001 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 [EMAIL PROTECTED] * * 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.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.ObjectInputStream; import java.util.Hashtable; import java.util.Vector; /** * This is where common Object manipulation routines should go. * * @author <a href="mailto:[EMAIL PROTECTED]";>Nissim Karpenstein</a> * @version $Id: ObjectUtils.java,v 1.1 2001/08/08 13:20:56 jvanzyl Exp $ */ public 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. */ public static Object isNull(Object o, Object dflt) { if (o == null) { return dflt; } else { return o; } } /** * Adds an object to a vector, making sure the object is in the * vector only once. * * @param v The vector. * @param o The object. */ public static void addOnce(Vector v, Object o) { if (! v.contains( o )) { v.addElement( o ); } } /** * 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. */ public static boolean equals( Object o1, Object o2 ) { if (o1 == null) { return (o2 == null); } else if (o2 == null) { // o1 is not null return false; } else { return o1.equals(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. */ public static final void safeAddToHashtable(Hashtable hash, Object key, Object value) throws NullPointerException { if (value == null) { hash.put ( key, "" ); } else { hash.put ( key, value ); } } }
