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}