Java tutorial
//package com.java2s; /* * This file is part of McIDAS-V * * Copyright 2007-2015 * Space Science and Engineering Center (SSEC) * University of Wisconsin - Madison * 1225 W. Dayton Street, Madison, WI 53706, USA * http://www.ssec.wisc.edu/mcidas * * All Rights Reserved * * McIDAS-V is built on Unidata's IDV and SSEC's VisAD libraries, and * some McIDAS-V source code is based on IDV and VisAD source code. * * McIDAS-V is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser Public License as published by * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * McIDAS-V 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 Public License for more details. * * You should have received a copy of the GNU Lesser Public License * along with this program. If not, see http://www.gnu.org/licenses. */ import java.util.Collection; import java.util.Collections; public class Main { /** * Creates a new {@code cl} instance (limited to things implementing * {@link Collection}) populated with the {@literal "varargs"}. Useful if * you truly despise {@link #arr(Object...)}, {@link #list(Object...)}, * or {@link #set(Object...)}. * * <p>Example: {@code Collection<Integer> ints = collect(PriorityBlockingQueue.class, 1, 2, 3);} * * @param cl A (non-abstract!) class that implements {@code Collection}. Cannot be {@code null}. * @param elements Objects that will be added to the collection. * * @return An instance of {@code cl} containing the given objects. * * @throws RuntimeException * if {@link java.lang.reflect.Constructor#newInstance(Object...) Constructor#newInstance(Object...)} * had problems. * * @see #arr(Object...) * @see #list(Object...) * @see #set(Object...) */ @SuppressWarnings({ "unchecked", "rawtypes" }) // the only things being added to the collection are objects of type "E" public static <E> Collection<E> collect(Class<? extends Collection> cl, E... elements) { try { Collection<E> c = cl.getConstructor().newInstance(); Collections.addAll(c, elements); return c; } catch (Exception e) { throw new RuntimeException("Problem creating a new " + cl, e); } } }