Java Collection to Array toStringArray(Collection collection)

Description

to String Array

License

Apache License

Declaration

public static String[] toStringArray(Collection<String> collection) 

Method Source Code

//package com.java2s;
/*//from  w  w w .  j  a va  2s  .c  om
 * Copyright 2000-2014 JetBrains s.r.o.
 *
 * 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;

public class Main {
    private static final int ARRAY_COPY_THRESHOLD = 20;
    public static final String[] EMPTY_STRING_ARRAY = new String[0];

    public static String[] toStringArray(Collection<String> collection) {
        return collection == null || collection.isEmpty() ? EMPTY_STRING_ARRAY
                : toArray(collection, new String[collection.size()]);
    }

    /**
     * This is a replacement for {@link Collection#toArray(Object[])}. For small collections it is faster to stay at java level and refrain
     * from calling JNI {@link System#arraycopy(Object, int, Object, int, int)}
     */

    public static <T> T[] toArray(Collection<T> c, T[] sample) {
        final int size = c.size();
        if (size == sample.length && size < ARRAY_COPY_THRESHOLD) {
            int i = 0;
            for (T t : c) {
                sample[i++] = t;
            }
            return sample;
        }

        return c.toArray(sample);
    }
}

Related

1. toStringArray(Collection collection)
2. toStringArray(Collection collection)
3. toStringArray(Collection collection)
4. toStringArray(Collection collection)
5. toStringArray(Collection collection)
6. toStringArray(Collection collection)
7. toStringArray(Collection collection)
8. toStringArray(Collection items)
9. toStringArray(Collection list)