/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2014, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* ---------------------
* ObjectUtilitiess.java
* ---------------------
* (C) Copyright 2003-2014, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 25-Mar-2003 : Version 1 (DG);
* 15-Sep-2003 : Fixed bug in clone(List) method (DG);
* 25-Nov-2004 : Modified clone(Object) method to fail with objects that
* cannot be cloned, added new deepClone(Collection) method.
* Renamed ObjectUtils --> ObjectUtils (DG);
* 11-Jan-2005 : Removed deprecated code in preparation for 1.0.0 release (DG);
* 18-Aug-2005 : Added casts to suppress compiler warnings, as suggested in
* patch 1260622 (DG);
* 16-Jun-2012 : Moved from JCommon to JFreeChart (DG);
*
*/
package org.jfree.chart.util;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Collection;
/**
* A collection of useful static utility methods for handling classes and object
* instantiation.
*/
public final class ObjectUtils {
/**
* Default constructor - private.
*/
private ObjectUtils() {
}
/**
* Returns <code>true</code> if the two objects are equal OR both
* <code>null</code>.
*
* @param o1 object 1 (<code>null</code> permitted).
* @param o2 object 2 (<code>null</code> permitted).
* @return <code>true</code> or <code>false</code>.
*/
public static boolean equal(final Object o1, final Object o2) {
if (o1 == o2) {
return true;
}
if (o1 != null) {
return o1.equals(o2);
}
else {
return false;
}
}
/**
* Returns a hash code for an object, or zero if the object is
* <code>null</code>.
*
* @param object the object (<code>null</code> permitted).
* @return The object's hash code (or zero if the object is
* <code>null</code>).
*/
public static int hashCode(final Object object) {
int result = 0;
if (object != null) {
result = object.hashCode();
}
return result;
}
/**
* Returns a clone of the specified object, if it can be cloned, otherwise
* throws a CloneNotSupportedException.
*
* @param <T> The object type.
* @param object the object to clone (<code>null</code> not permitted).
* @return A clone of the specified object.
* @throws CloneNotSupportedException if the object cannot be cloned.
*/
public static <T> T clone(T object) throws CloneNotSupportedException {
if (object == null) {
throw new IllegalArgumentException("Null 'object' argument.");
}
if (object instanceof PublicCloneable) {
PublicCloneable pc = (PublicCloneable) object;
return (T) pc.clone();
} else {
try {
Method method = object.getClass().getMethod("clone");
if (Modifier.isPublic(method.getModifiers())) {
return (T) method.invoke(object);
}
}
catch (NoSuchMethodException e) {
//Log.warn("Object without clone() method is impossible.");
throw new CloneNotSupportedException(e.getMessage());
}
catch (IllegalAccessException e) {
//Log.warn("Object.clone(): unable to call method.");
throw new CloneNotSupportedException(e.getMessage());
}
catch (InvocationTargetException e) {
//Log.warn("Object without clone() method is impossible.");
throw new CloneNotSupportedException(e.getMessage());
}
}
throw new CloneNotSupportedException("Failed to clone.");
}
/**
* Returns a new collection containing clones of all the items in the
* specified collection.
*
* @param <T> The object type.
* @param <C> The collection type.
* @param collection the collection (<code>null</code> not permitted).
* @return A new collection containing clones of all the items in the
* specified collection.
* @throws CloneNotSupportedException if any of the items in the collection
* cannot be cloned.
*/
public static <T, C extends Collection<T>> C deepClone(final C collection)
throws CloneNotSupportedException {
if (collection == null) {
throw new IllegalArgumentException("Null 'collection' argument.");
}
// all JDK-Collections are cloneable ...
// and if the collection is not clonable, then we should throw
// a CloneNotSupportedException anyway ...
final C result = ObjectUtils.clone(collection);
result.clear();
for (T item : collection) {
if (item == null) {
result.add(null);
} else {
result.add(clone(item));
}
}
return result;
}
}