Что ему надо?)) Почему не проходит?
package com.javarush.task.task18.task1825;
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
/*
Собираем файл
*/
public class Solution {
public static void main(String[] args) throws IOException {
ArrayList<Integer> num = new ArrayList<>();
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String file="";
String mainFile = "";
while (!(file = reader.readLine()).equals("end")){
num.add(mySplit(file));
if (!file.equals("end")){mainFile = file;}
}
String[] ff = mainFile.split(".part");
String filename = ff[0];
Collections.sort(num);
FileInputStream inputStream;
FileOutputStream outputStream = new FileOutputStream(filename,true);
for (int i = 0; i <num.size() ; i++) {
inputStream = new FileInputStream(filename+".part"+num.get(i));
while (inputStream.available()>0){
outputStream.write(inputStream.read());
}
inputStream.close();
}
// inputStream.close();
outputStream.close();
}
public static int mySplit(String name){
String[] part = name.split(".part");
int num = Integer.parseInt(part[1]);
return num;
}
}