Return the first element in ' candidates ' that is contained in ' source '. - Java java.util

Java examples for java.util:Collection Contain

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Description

Return the first element in ' candidates ' that is contained in ' source '.

Demo Code

/*/*from   w  w  w .java 2  s.  c o  m*/
 * Copyright 2002-2015 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.
 */
//package com.java2s;
import java.util.*;

public class Main {
    public static void main(String[] argv) {
        Collection source = java.util.Arrays.asList("asdf", "java2s.com");
        Collection candidates = java.util.Arrays.asList("asdf",
                "java2s.com");
        System.out.println(findFirstMatch(source, candidates));
    }

    /**
     * Return the first element in '{@code candidates}' that is contained in
     * '{@code source}'. If no element in '{@code candidates}' is present in
     * '{@code source}' returns {@code null}. Iteration order is
     * {@link Collection} implementation specific.
     *
     * @param source     the source Collection
     * @param candidates the candidates to search for
     * @return the first present object, or {@code null} if not found
     */
    @SuppressWarnings("unchecked")
    public static <E> E findFirstMatch(Collection<?> source,
            Collection<E> candidates) {
        if (isEmpty(source) || isEmpty(candidates)) {
            return null;
        }
        for (Object candidate : candidates) {
            if (source.contains(candidate)) {
                return (E) candidate;
            }
        }
        return null;
    }

    /**
     * Return {@code true} if the supplied Collection is {@code null} or empty.
     * Otherwise, return {@code false}.
     *
     * @param collection the Collection to check
     * @return whether the given Collection is empty
     */
    public static boolean isEmpty(Collection<?> collection) {
        return (collection == null || collection.isEmpty());
    }

    /**
     * Return {@code true} if the supplied Map is {@code null} or empty.
     * Otherwise, return {@code false}.
     *
     * @param map the Map to check
     * @return whether the given Map is empty
     */
    public static boolean isEmpty(Map<?, ?> map) {
        return (map == null || map.isEmpty());
    }

    /**
     * Check whether the given Iterator contains the given element.
     *
     * @param iterator the Iterator to check
     * @param element  the element to look for
     * @return {@code true} if found, {@code false} else
     */
    public static boolean contains(Iterator<?> iterator, Object element) {
        if (iterator != null) {
            while (iterator.hasNext()) {
                Object candidate = iterator.next();
                if (org.springframework.util.ObjectUtils.nullSafeEquals(
                        candidate, element)) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Check whether the given Enumeration contains the given element.
     *
     * @param enumeration the Enumeration to check
     * @param element     the element to look for
     * @return {@code true} if found, {@code false} else
     */
    public static boolean contains(Enumeration<?> enumeration,
            Object element) {
        if (enumeration != null) {
            while (enumeration.hasMoreElements()) {
                Object candidate = enumeration.nextElement();
                if (org.springframework.util.ObjectUtils.nullSafeEquals(
                        candidate, element)) {
                    return true;
                }
            }
        }
        return false;
    }
}

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