В чём может быть проблема?
package com.javarush.task.task18.task1808;
/*
Разделение файла
*/
import java.io.*;
import java.util.ArrayList;
public class Solution {
public static void main(String[] args) throws IOException {
BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
FileInputStream fis = new FileInputStream(bf.readLine());
FileOutputStream output1 = new FileOutputStream(bf.readLine());
FileOutputStream output2 = new FileOutputStream(bf.readLine());
bf.close();
byte[]buffer = new byte[fis.available()];
if(fis.available() > 0){
fis.read(buffer);
}
int half = buffer.length / 2;
output1.write(buffer, 0, half);
output2.write(buffer, half, buffer.length - half);
fis.close();
output1.close();
output2.close();
}
}