/*
* Copyright (c) 2005-2011 Vincent Vandenschrick. All rights reserved.
*
* This file is part of the Jspresso framework.
*
* Jspresso 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 3 of the License, or
* (at your option) any later version.
*
* Jspresso 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 Jspresso. If not, see <http://www.gnu.org/licenses/>.
*/
package org.jspresso.framework.util.collection;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import org.jspresso.framework.util.exception.NestedRuntimeException;
/**
* Helper class for collections management.
*
* @version $LastChangedRevision: 3701 $
* @author Vincent Vandenschrick
*/
public final class CollectionHelper {
private CollectionHelper() {
// private constructor for helper class
}
/**
* Clones a collection trying to invoke the <code>clone()</code> method
* reflectively. If the latter is unsuccessful, returns an HashSet for a Set
* and an ArrayList for a List.
*
* @param <E>
* the type the collection element
* @param collection
* the original collection
* @return the cloned collection.
*/
@SuppressWarnings("unchecked")
public static <E> Collection<E> cloneCollection(Collection<E> collection) {
if (collection == null) {
return null;
}
Collection<E> clonedCollection = null;
if (collection instanceof Cloneable) {
// try to invoke the clone method reflectively
try {
clonedCollection = (Collection<E>) collection.getClass().getMethod(
"clone", (Class[]) null).invoke(collection, (Object[]) null);
} catch (IllegalArgumentException ex) {
throw new NestedRuntimeException(ex);
} catch (SecurityException ex) {
throw new NestedRuntimeException(ex);
} catch (IllegalAccessException ex) {
throw new NestedRuntimeException(ex);
} catch (InvocationTargetException ex) {
throw new NestedRuntimeException(ex);
} catch (NoSuchMethodException ex) {
// Do nothing. the method simply does not exist.
}
}
if (clonedCollection == null) {
if (collection instanceof Set) {
clonedCollection = new HashSet<E>(collection);
} else if (collection instanceof List) {
clonedCollection = new ArrayList<E>(collection);
}
}
return clonedCollection;
}
}