Method concat

src/main/java/org/apache/groovy/util/Arrays.java:38–60

Concatenate arrays and ignore null array @param arrays arrays to merge @param array component type @return the concatenated array

(T[]... arrays)

     * @return the concatenated array
     */
    @SuppressWarnings("unchecked")
    public static <T> T[] concat(T[]... arrays) {
        if (null == arrays || 0 == arrays.length) return null;

        int resultLength =
                java.util.Arrays.stream(arrays)
                        .filter(Objects::nonNull)
                        .map(e -> e.length)
                        .reduce(0, Integer::sum);
        T[] resultArray = (T[]) Array.newInstance(arrays[0].getClass().getComponentType(), resultLength);

        for (int i = 0, n = arrays.length, curr = 0; i < n; i++) {
            T[] array = arrays[i];

            if (null == array) continue;

            int length = array.length;
            System.arraycopy(array, 0, resultArray, curr, length);
            curr += length;
        }

        return resultArray;
    }

    private Arrays() {}
}