Code works but doesn't pass the verification.

Question about the task

Building a file

Java Core, Level 8, Lesson 11

Under discussion

Code works but doesn't pass the verification for about 80% WFT ??? ^)

Let's build a file from various pieces.
Read file names from the console.
Each file has a name: <someName>.partN.

For example, Lion.avi.part1, Lion.avi.part2, ..., Lion.avi.part37.

The file names are supplied in random order. The word "end" is used to stop reading in file names.
In the folder where all the files are located, create a file without the "part" suffix, i.e. without ".<partN>".

For example, Lion.avi.

Use a buffer to copy all the bytes from the partial files to the created file.
Copy the first in the proper order, first the first part, then the second, ..., finally - the last part.
Close the streams.

Requirements:

The program must read file names from the console until the word "end" is entered.
Create a stream to write to the file without the "part" suffix (".<partN>") in the folder with all the "part" files.
Copy all the bytes from the *.partN files to the new file.
You should use a buffer for the reading and writing.
The file streams must be closed.
Don't use static variables.

package com.codegym.task.task18.task1825; import java.io.*; import java.util.*; /* Building a file */ public class Solution { public static void main(String[] args) throws IOException { ArrayList<Integer> indexArray = new ArrayList<>(); BufferedReader readerName = new BufferedReader(new InputStreamReader(System.in)); String fileName = null, previousFileName, nameBeforePart, nameAfterPart; while (true) { previousFileName = fileName; fileName = readerName.readLine(); if (fileName.equals("end")) { // Get the name of file for writing String[] tmp = previousFileName.split("part" + getPartIndex(previousFileName) + "\\.", 2); nameBeforePart = tmp[0]; nameAfterPart = tmp[1]; break; } indexArray.add(getPartIndex(fileName)); } readerName.close(); Collections.sort(indexArray); // Sort our array BufferedOutputStream writer = new BufferedOutputStream(new FileOutputStream(nameBeforePart + nameAfterPart)); BufferedInputStream reader; for(Integer index : indexArray) { reader = new BufferedInputStream(new FileInputStream(nameBeforePart + "part" + index + "." + nameAfterPart)); byte[] data = new byte[reader.available()]; while(reader.available() > 0) { reader.read(data); writer.write(data); } reader.close(); } writer.close(); } public static int getPartIndex(String name){ // Get the number after part... String[] tmp = name.split("part", 2); String[] tmp2 = tmp[1].split("\\.",2); return (Integer.parseInt(tmp2[0])); } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

14 May 2019, 15:15

useful

I get an index out of range exception. Line 21 splits the 'previousFileName' from the very end by the regex 'part#\\.'.... this isn't matching anything and the returned split is tmp[0] = previousFileName (in full). There is no tmp[1] for line 23. For example, when end is entered after all files: - previousFileName = C:\temp\test.txt.part3 - line 21 splits by regex "part3\\.", no match because part3# (where # is any digit 1 time) does not exist in the previousFileName - tmp[0] = C:\temp\test.txt.part3 - line 22 sets nameBeforePart to tmp[0] - line 23 sets nameAfterPart to tmp[1] - "ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1" thrown.

Denis

Level 25 , Vancouver, Canada

14 May 2019, 16:59

Oh I see my mistake. Thank you. I thought the format is Lion.part1.avi, Lion.part2.avi ..., Lion.part37.avi