return true if collection has only 1 item (null safe) - Java java.util

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Description

return true if collection has only 1 item (null safe)

Demo Code

/*//from  w  ww.ja  va2  s .  c o  m
 * ObjectLab, http://www.objectlab.co.uk/open is sponsoring the ObjectLab Kit.
 *
 * Based in London, we are world leaders in the design and development
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 *
 * $Id: AbstractDateCalculator.java 309 2010-03-23 21:01:49Z marchy $
 *
 * Copyright 2006 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.Collection;

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

    /**
     * @return true if collection has only 1 item (null safe).
     */
    public static boolean hasOneItem(final Collection<?> col) {
        return col != null && col.size() == 1;
    }

    /**
     * @return size of collection if not null, otherwise 0.
     */
    public static int size(final Collection<?> col) {
        return col != null ? col.size() : 0;
    }
}

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