/*
* Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software;Designed and Developed mainly by many Chinese
* opensource volunteers. you can redistribute it and/or modify it under the
* terms of the GNU General Public License version 2 only, as published by the
* Free Software Foundation.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Any questions about this component can be directed to it's project Web address
* https://code.google.com/p/opencloudb/.
*
*/
package org.opencloudb.util;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
/**
* @author mycat
*/
public class CollectionUtil {
/**
* @param orig
* if null, return intersect
*/
public static Set<? extends Object> intersectSet(Set<? extends Object> orig, Set<? extends Object> intersect) {
if (orig == null)
return intersect;
if (intersect == null || orig.isEmpty())
return Collections.emptySet();
Set<Object> set = new HashSet<Object>(orig.size());
for (Object p : orig) {
if (intersect.contains(p))
set.add(p);
}
return set;
}
}