Java Collection Merge mergeCollection( final Collection col1, final Collection col2)

Description

Merge collections where all objects are of the same type.

License

Open Source License

Parameter

Parameter	Description
col1	a parameter
col2	a parameter

Declaration

public static <T> Collection<T> mergeCollection(
        final Collection<T> col1, final Collection<T> col2) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2004-2013/*  ww  w  .  j  av a 2  s  .c  o  m*/
 * Contributors: L. Armanet, M. Camerlenghi, L. Cardonne, S. Delageniere,
 *               L. Duparchy, S. Ohlsson, P. Pascal, I. Schneider, S.Schulze,
 *               F. Torres
 * 
 * This file is part of the MIS tools package.
 * 
 * The MIS tools package is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * The MIS tools package is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the MIS tools package.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/

import java.util.ArrayList;

import java.util.Collection;

public class Main {
    /**
     * Merge collections where all objects are of the same type.
     * 
     * @param col1
     * @param col2
     * @return
     */
    public static <T> Collection<T> mergeCollection(
            final Collection<T> col1, final Collection<T> col2) {
        if (col1 == null) {
            if (col2 == null) {
                return null;
            }
            return col2;
        }
        if (col2 == null) {
            return col1;
        }
        Collection<T> result = new ArrayList<T>(col1.size() + col2.size());
        result.addAll(col1);
        result.addAll(col2);
        return result;
    }
}

Related

1. merge(Collection... collections)
2. merge(Collection... elems)
3. merge(final Collection values)
4. merge(J just, Collection justs)
5. mergeArrayIntoCollection(T[] array, Collection collection)
6. mergeCollection(Collection a, Collection b)
7. mergeCollections(Collection... inCollections)