Any ideas what's wrong with this code?
package com.codegym.task.task18.task1825;
import java.io.*;
import java.util.SortedSet;
import java.util.TreeSet;
public class Solution {
public static void main(String[] args) throws IOException {
if(true) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String fileName;
SortedSet<String> set = new TreeSet<>();
while (true) {
fileName = br.readLine();
if (fileName.equals("end")) {
br.close();
break;
}
set.add(fileName);
}
// File file = new File(set.first().substring(0, fileName.lastIndexOf('.')));
// file.getParentFile().mkdirs();
// file.createNewFile();
String fileOutputName = set.first().substring(0, fileName.lastIndexOf('.'));
BufferedOutputStream fileOutputStream = new BufferedOutputStream(new FileOutputStream(fileOutputName));
for (String file : set){
BufferedInputStream fileInputStream = new BufferedInputStream(new FileInputStream(file));
while (fileInputStream.available() > 0)
fileOutputStream.write(fileInputStream.read());
fileInputStream.close();
}
fileOutputStream.close();
}
}
}