Java Collection Intersect intersection(Collection> availableValuesByDescriptor)

Description

intersection

License

Apache License

Declaration

public static <T> List<T> intersection(Collection<? extends Collection<T>> availableValuesByDescriptor) 

Method Source Code

//package com.java2s;
/*//from w ww . j a v a2  s .  c  om
 * Copyright 2011 the original author or authors.
 *
 * 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.
 */

import java.util.*;

public class Main {
    public static <T> List<T> intersection(Collection<? extends Collection<T>> availableValuesByDescriptor) {
        List<T> result = new ArrayList<T>();
        Iterator<? extends Collection<T>> iterator = availableValuesByDescriptor.iterator();
        if (iterator.hasNext()) {
            Collection<T> firstSet = iterator.next();
            result.addAll(firstSet);
            while (iterator.hasNext()) {
                Collection<T> next = iterator.next();
                result.retainAll(next);
            }
        }
        return result;

    }

    /**
     * Utility for adding an iterable to a collection.
     *
     * @param t1 The collection to add to
     * @param t2 The iterable to add each item of to the collection
     * @param <T> The element type of t1
     * @return t1
     */
    public static <T> Collection<T> addAll(Collection<T> t1, Iterable<? extends T> t2) {
        for (T t : t2) {
            t1.add(t);
        }
        return t1;
    }

    /**
     * Utility for adding an array to a collection.
     *
     * @param t1 The collection to add to
     * @param t2 The iterable to add each item of to the collection
     * @param <T> The element type of t1
     * @return t1
     */
    public static <T> Collection<T> addAll(Collection<T> t1, T... t2) {
        Collections.addAll(t1, t2);
        return t1;
    }
}

Related

1. intersectingCollections(Collection collection1, Collection collection2)
2. intersectInto(C into, Collection... from)
3. intersection( Collection> coll)
4. intersection(Collection a, Collection b)
5. intersection(Collection> collectionOfCollections)
6. intersection(Collection... collections)
7. intersection(Collection> sets)
8. intersection(Collection a, Collection b)
9. intersection(Collection a, Collection b)