Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
/*
 * Copyright 2016 Dmitry Korotych (dkorotych at gmail dot com).
 *
 * 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.Arrays;

import java.util.Collections;
import java.util.List;

import java.util.Optional;

public class Main {
    /**
     * Return the "safe" list. This method never returns a value of
     * {@code null}, if the input list is equal to {@code null}, then instead it
     * will return an empty list
     *
     * @param <T> Type of list of elements
     * @param list List of elements
     * @return The input or an empty list
     */
    public static <T> List<T> getSafeList(final List<T> list) {
        return Optional.ofNullable(list).orElse(Collections.<T>emptyList());
    }

    /**
     * Return the "safe" list. This method never returns a value of {@code null}
     *
     * @param <T> Type of list of elements
     * @param items Elements
     * @return The input sequence transformed to list or an empty list
     * @see Collections#emptyList()
     * @see Arrays#asList(java.lang.Object...)
     */
    @SafeVarargs
    @SuppressWarnings("varargs")
    public static <T> List<T> getSafeList(final T... items) {
        if (items == null) {
            return Collections.<T>emptyList();
        } else {
            return Arrays.asList(items);
        }
    }
}