Maximum integer from integer array of any length

App.java

package ru.cohab;

import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;

public class App {
    public static final int COUNT = 4;

    public static void main(String[] args) throws Exception {
        System.out.println("Enter " + COUNT + " numbers:");

        App app = new App();

        int[] test = app.inputNums(4);

        System.out.println("Maximum: " + app.maximum(test));
    }

    private int[] inputNums(int size) throws IOException {
        int[] result = new int[size];
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader br = new BufferedReader(isr);

        for (int i = 0; i < size; i++) {
            result[i] = Integer.parseInt(br.readLine());
        }

        return result;
    }

    private int maximum(int a, int b) {
        if (a < b) {
            return b;
        }

        return a;
    }

    private int maximum(int[] numbers) {
        int size = numbers.length;

        if (size == 1) {
            return numbers[0];
        }

        if (size == 2) {
            return maximum(numbers[0], numbers[1]);
        }

        int middle = size / 2;

        int[] firstPart = new int[middle];
        int[] secondPart = new int[size - middle];

        for (int i = 0; i < middle; i++) {
            firstPart[i] = numbers[i];
        }

        for (int i = middle; i < size; i++) {
            secondPart[i - middle] = numbers[i];
        }

        return maximum(maximum(firstPart), maximum(secondPart));
    }
}