Struggling to validate part3. It seems to work, only wont pass validation. Any insight welcome. tks

Question about the task

Building a file

Java Core, Level 8, Lesson 11

Under discussion

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 { TreeMap<Integer,String> sortedMap = new TreeMap(); BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String filename = ""; String root = ""; String[] tokens = null; while (!(filename = reader.readLine()).equals("end")) { tokens = filename.split("\\.(?=[^.]+$)"); root = tokens[0]; int count = Integer.parseInt(tokens[1].replaceAll("part", "")); sortedMap.put(count, filename); } File outputFile = new File(root); Iterator<Integer> iterator = sortedMap.keySet().iterator(); BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(outputFile)); while (iterator.hasNext()) { Integer key = iterator.next(); File file = new File(sortedMap.get(key)); BufferedInputStream bufferedInputStream = new BufferedInputStream(new FileInputStream(file)); int nRead=0; while ((nRead = bufferedInputStream.read()) != -1) { bufferedOutputStream.write(nRead); } bufferedInputStream.close(); } bufferedOutputStream.close(); } }

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Nouser

Level 36 , Germany

6 October 2020, 15:26

Tested your code and it works for me. Sorting and output filename are both OK. And it writes to the file with that output filename. No clue what else it looks for. I post my solution. Maybe you can see what I'm not able to spot.

public static void main(String[] args) throws IOException {
    //TreeSet with modified comparator, extracts the numbers after .part and sorts depending on the resulting numbers ascending
    TreeSet<String> set = new TreeSet<>(new Comparator<String>() {
        public int compare(String o1, String o2) {
            return parseFileName(o1) - parseFileName(o2);
        }
    });

    BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

    //read file names and add to set
    String fileName = null;
    while (!(fileName = reader.readLine()).equals("end")) set.add(fileName);
    reader.close();

    //check if there are entries in the set, if no, skip reading
    if (set.size() > 0) {
        //calculate the output file name, open output stream
        String outputFileName = set.first().substring(0, set.first().lastIndexOf("."));
        BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(outputFileName));

        //loop through the set, read and write
        BufferedInputStream in;
        for (String inputFileName : set) {
            in = new BufferedInputStream(new FileInputStream(inputFileName));
            while (in.available() > 0) out.write(in.read());
            in.close();
        }
        out.close();
    } //end set size
}

//returns the number from the filename after .part
public static int parseFileName(String s) {
    return Integer.parseInt(s.substring(s.lastIndexOf(".")).replaceAll("\\D+", ""));
}

Lgd

Level 20 , London, United Kingdom

6 October 2020, 16:50

thanks...it works me aswell...but it won't validate. frustrated. best L