Java Collection First getFirstElement(Collection coll)

Description

INTERNAL: Gets the first object in the collection.

License

Apache License

Declaration

public static <T> T getFirstElement(Collection<T> coll) throws NoSuchElementException 

Method Source Code

//package com.java2s;
/*//  www  .j a va  2s . c om
 * #!
 * Ontopia Engine
 * #-
 * Copyright (C) 2001 - 2013 The Ontopia Project
 * #-
 * 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.Collection;

import java.util.List;

import java.util.NoSuchElementException;

public class Main {
    /**
     * INTERNAL: Gets the first object in the collection. If the
     * collection does not contain any elements NoSuchElementException
     * is thrown.<p>
     *
     * @since 1.3.4
     */
    public static <T> T getFirstElement(Collection<T> coll) throws NoSuchElementException {

        if (coll instanceof List)
            try {
                return ((List<T>) coll).get(0);
            } catch (IndexOutOfBoundsException e) {
                throw new NoSuchElementException();
            }
        else
            return coll.iterator().next();
    }
}

Related

1. getFirst(Collection set, boolean remove)
2. getFirst(Collection ts)
3. getFirst(final Collection collection)
4. getFirstAndOnly(Collection c)
5. getFirstClassOfType(Collection l, Class type)
6. getFirstElement(Collection collection, T defaultValue)
7. getFirstElementOrNull(Collection collection)
8. getFirstElementOrNull(Collection coll)
9. getFirstItem(Collection c)