Не выполнены 2 - 5 условия. Подскажите, пожалуйста, что не так
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.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.util.Comparator;
import java.util.Set;
import java.util.TreeSet;
import java.util.Iterator;
/*
Собираем файл
*/
public class Solution {
public static void main(String[] args) throws Exception {
Comparator<String> comp = new Comparator<String>(){
public int compare(String s1, String s2) {
if (s1.length()==s2.length()) return s1.compareTo(s2);
else if (s1.length()<s2.length()) return -1;
else return 1;
}
};
Set<String> set = new TreeSet<>(comp);
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while (true) {
String s = br.readLine();
if (!s.equals("end")) set.add(s);
else break;
}
Iterator<String> itr = set.iterator();
String s = "";
if (itr.hasNext()) s = itr.next();
String s1 = "";
for (int i = 0; i<=s.length()-1; i++)
if (s.substring(i, i+5).equals(".part")) {
s1 = s.substring(0, i+1);
break;
}
FileOutputStream fos = new FileOutputStream(new File(s1));
BufferedOutputStream bos = new BufferedOutputStream(fos);
FileInputStream fis = new FileInputStream(s);
BufferedInputStream bis = new BufferedInputStream(fis);
while (bis.available() > 0) {
int data = bis.read();
bos.write(data);
}
bis.close();
bos.close();
while (itr.hasNext()) {
fis = new FileInputStream(itr.next());
bis = new BufferedInputStream(fis);
while (bis.available() > 0) {
int data = bis.read();
bos.write(data);
}
bis.close();
bos.close();
}
}
}