/* * Copyright 2012-2015 org.opencloudb. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** * (created at 2011-10-24) */ 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; } }