001/** 002 * 003 * Copyright 2015-2018 Florian Schmaus 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.jivesoftware.smack.util; 018 019import java.util.ArrayList; 020import java.util.Collection; 021import java.util.Iterator; 022import java.util.List; 023 024public class CollectionUtil { 025 026 public static <T> Collection<T> requireNotEmpty(Collection<T> collection, String collectionName) { 027 if (collection == null) { 028 throw new NullPointerException(collectionName + " must not be null."); 029 } 030 if (collection.isEmpty()) { 031 throw new IllegalArgumentException(collectionName + " must not be empty."); 032 } 033 return collection; 034 } 035 036 public static <T, C extends Collection<T>> List<T> removeUntil(C collection, Predicate<T> predicate) { 037 List<T> removedElements = new ArrayList<>(collection.size()); 038 for (Iterator<T> it = collection.iterator(); it.hasNext();) { 039 T t = it.next(); 040 if (predicate.test(t)) { 041 break; 042 } 043 removedElements.add(t); 044 it.remove(); 045 } 046 return removedElements; 047 } 048 049 public interface Predicate<T> { 050 boolean test(T t); 051 } 052}