Clone and Deep clone
/*
* AFreeChart : a free chart library for Android(tm) platform.
* (based on JFreeChart and JCommon)
*
*
* (C) Copyright 2010, by Icom Systech Co., Ltd.
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
*
* Project Info:
* AFreeChart: http://code.google.com/p/afreechart/
* JFreeChart: http://www.jfree.org/jfreechart/index.html
* JCommon : http://www.jfree.org/jcommon/index.html
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* [Android is a trademark of Google Inc.]
*
* ---------------------
* ObjectUtilitiess.java
* ---------------------
*
* (C) Copyright 2010, by Icom Systech Co., Ltd.
*
* Original Author: shiraki (for Icom Systech Co., Ltd);
* Contributor(s): Sato Yoshiaki ;
* Niwano Masayoshi;
*
* Changes (from 19-Nov-2010)
* --------------------------
* 19-Nov-2010 : port JCommon 1.0.16 to Android as "AFreeChart"
*
* ------------- JFreeChart ---------------------------------------------
* (C) Copyright 2003-2005, 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 --> ObjectUtilities (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);
*
*/
package org.afree.util;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Collection;
import java.util.Iterator;
import android.util.Log;
/**
* A collection of useful static utility methods for handling classes and object
* instantiation.
*
* @author Thomas Morgner
*/
final class ObjectUtilities {
/**
* 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 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 Object clone(final Object object)
throws CloneNotSupportedException {
if (object == null) {
throw new IllegalArgumentException("Null 'object' argument.");
}
if (object instanceof PublicCloneable) {
final PublicCloneable pc = (PublicCloneable) object;
return pc.clone();
} else {
try {
final Method method = object.getClass().getMethod("clone",
(Class[]) null);
if (Modifier.isPublic(method.getModifiers())) {
return method.invoke(object, (Object[]) null);
}
} catch (NoSuchMethodException e) {
Log.w("ObjectUtilities",
"Object without clone() method is impossible.");
} catch (IllegalAccessException e) {
Log.w("ObjectUtilities",
"Object.clone(): unable to call method.");
} catch (InvocationTargetException e) {
Log.w("ObjectUtilities",
"Object without clone() method is impossible.");
}
}
throw new CloneNotSupportedException("Failed to clone.");
}
/**
* Returns a new collection containing clones of all the items in the
* specified collection.
*
* @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 Collection deepClone(final Collection 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 Collection result = (Collection) ObjectUtilities
.clone(collection);
result.clear();
final Iterator iterator = collection.iterator();
while (iterator.hasNext()) {
final Object item = iterator.next();
if (item != null) {
result.add(clone(item));
} else {
result.add(null);
}
}
return result;
}
}
/**
* An interface that exposes the clone() method.
*
* @author David Gilbert
*/
interface PublicCloneable extends Cloneable {
/**
* Returns a clone of the object.
*
* @return A clone.
*
* @throws CloneNotSupportedException
* if cloning is not supported for some reason.
*/
public Object clone() throws CloneNotSupportedException;
}
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