CodeGym/Help with Java Tasks/Please help

Level 30

London

07.04.2021
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13comments

Please help

Question about the task

Resolved

I'm particularly confused about points: 1.1) what am I supposed to do with the passed filePath argument? 5.2) what would be the second argument passed to the addNewZipEntry() method in this case? 5.3.2) what fileNames variable?

It's time to refactor the ZipFileManager class. The createZip method has code that we're also going to need in the methods that will add files to or remove them from an archive, extract files, etc. We'll implement those methods later, but we can move the common code to separate methods now.
Additionally, the createZip method can only create an archive from a single file, but we would like to be able to zip an entire folder. We won't create a separate method for this, since you can pass both a directory and a regular file to the createZip(Path source) method.

Today's tasks:
1. Implement a private void addNewZipEntry(ZipOutputStream zipOutputStream, Path filePath, Path fileName) throws Exception method in the ZipFileManager class.
It must:
1.1. Create an InputStream for the file named fileName located in the filePath directory
1.2. Create a new ZipEntry, using fileName as the name after converting it to a String
1.3. Copy the data from the InputStream (from step 1.1) to the zipOutputStream parameter
1.4. Close the zip entry
1.5. Close the InputStream using try-with-resources
2. Replace part of the createZip method's code with a call to the addNewZipEntry method. Pass source.getParent() as the filePath parameter, and source.getFileName() as the filename.
3. Implement a private void copyData(InputStream in, OutputStream out) throws Exception method. It must read data from "in" and write to "out", until it reads through everything.
4. Replace part of the addNewZipEntry method's code with a call to the copyData method.
5. Let's return to createZip:
5.1. At the beginning of the method, check to see if the directory (zipFile.getParent()) where we will create zipFile exists; if not, then create it.
5.2. If source is a regular file (use Files.isRegularFile to check), then simply call addNewZipEntry.
5.3. If source is a directory (use Files.isDirectory to check), then:
5.3.1. Create a FileManager object, passing source to the constructor
5.3.2. Get a list of files from the file manager, and save them to the fileNames variable
5.3.3. Call addNewZipEntry(zipOutputStream, source, fileName) for each element of fileNames.
5.4. If source isn't a folder or a file, throw a PathNotFoundException.

Requirements:

Add a private void addNewZipEntry(ZipOutputStream zipOutputStream, Path filePath, Path fileName) throws Exception method to the ZipFileManager class.
The addNewZipEntry method must be implemented according to the task conditions.
Replace part of the createZip method's code with a call to the addNewZipEntry method.
Add a private void copyData(InputStream in, OutputStream out) throws Exception method to the ZipFileManager class.
The copyData method must read data from "in" and write to "out" until it reads all of the bytes.
Replace part of the addNewZipEntry method's code with a call to the new copyData method.
The createZip method in the ZipFileManager class must be completed according to the task conditions.

package com.codegym.task.task31.task3110; import com.codegym.task.task31.task3110.exception.NoSuchZipFileException; import java.io.IOException; public class Archiver { public static void main(String[] args) throws IOException { Operation operation = null; do { try { operation = askOperation(); CommandExecutor.execute(operation); } catch (NoSuchZipFileException e) { ConsoleHelper.writeMessage("You didn't select an archive or you selected an invalid file."); } catch (Exception e) { ConsoleHelper.writeMessage("An error occurred. Please check the entered data."); } } while (operation != Operation.EXIT); } public static Operation askOperation() throws IOException { ConsoleHelper.writeMessage(""); ConsoleHelper.writeMessage("Select an operation:"); ConsoleHelper.writeMessage(String.format("\t %d - Zip files into an archive", Operation.CREATE.ordinal())); ConsoleHelper.writeMessage(String.format("\t %d - Add a file to an archive", Operation.ADD.ordinal())); ConsoleHelper.writeMessage(String.format("\t %d - Remove a file from an archive", Operation.REMOVE.ordinal())); ConsoleHelper.writeMessage(String.format("\t %d - Extract an archive", Operation.EXTRACT.ordinal())); ConsoleHelper.writeMessage(String.format("\t %d - View the contents of an archive", Operation.CONTENT.ordinal())); ConsoleHelper.writeMessage(String.format("\t %d - Exit", Operation.EXIT.ordinal())); return Operation.values()[ConsoleHelper.readInt()]; } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

7 April 2021, 15:52

1.1) filePath is the directory. fileName is a file that exists in that directory. Example: filePath = "C:\\users\me\destop\zipFile" fileName = "fileToAdd.txt" You are going to need to combine these before opening an input stream: "C:\\users\me\destop\zipFile\fileToAdd.txt" ***be aware that the task says to use fileName as the ZipEntry, not the combined value*** 5.1) Line 20 is checking if the parent does not exists..... it should create the parent if this is the true. 5.2) This should be further understood when you understand subtask 1.1 5.3.2) I don't know if this is necessary as your code handles it properly. What is is asking for is this (lines 28-32 of the above code):

else if (Files.isDirectory(source)){
   FileManager fileManager = new FileManager(source);
   List<Path> fileNames = fileManager.getFileList(); // << this
   for (Path path : fileNames){
      addNewZipEntry(zipOutputStream, source, path);
   }
}

But your code is functionally identical so it probably doesn't matter either way.

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 12:26

public class ZipFileManager {

    private Path zipFile;

    public ZipFileManager(Path zipFile) {
        this.zipFile = zipFile;
    }

    public void createZip(Path source) throws Exception{
        if (!Files.exists(zipFile.getParent())){
            Files.createDirectories(zipFile.getParent());
        }

        try (ZipOutputStream zipOutputStream = new ZipOutputStream(Files.newOutputStream(zipFile))) {
            if (Files.isRegularFile(source)) {
                addNewZipEntry(zipOutputStream, source, source);
            }
            else if (Files.isDirectory(source)){
                FileManager fileManager = new FileManager(source);
                List<Path> fileNames = fileManager.getFileList();
                for (Path path : fileNames){
                    addNewZipEntry(zipOutputStream, path, path);
                }
            }
            else {
                throw new PathNotFoundException();
            }

        }
    }

    private void addNewZipEntry(ZipOutputStream zipOutputStream, Path filePath, Path fileName) throws Exception{
        try(InputStream inputStream = Files.newInputStream(fileName)) {
            ZipEntry zipEntry = new ZipEntry(fileName.getFileName().toString());
            zipOutputStream.putNextEntry(zipEntry);

            copyData(inputStream, zipOutputStream);

            zipOutputStream.closeEntry();
        }
    }

    private void copyData(InputStream in, OutputStream out) throws Exception{
        while (in.available() > 0){
            out.write(in.read());
        }
    }
}

This is my new code - it's still failing the same conditions

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 13:15

That is because line 33, 'fileName' does not exist by itself, it exists as a file inside "filePath". You need "filepath + filename" (don't combine them verbatim like this, use the proper method) to open the stream

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 13:19

also line 16 is still incorrect. Source is going to be the full qualified path to the file. This means that it would be something like this: "C:\\users\me\desktop\zipFile\fileToAdd.txt" If that were 'source' then this would need to be passed to line 16:

addNewZipEntry(zipOutputStream,"C:\\users\me\desktop\zipFile" , "fileToAdd.txt");

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 14:03

Tried changing it to:

public void createZip(Path source) throws Exception{
        if (!Files.exists(zipFile.getParent())){
            Files.createDirectories(zipFile.getParent());
        }

        try (ZipOutputStream zipOutputStream = new ZipOutputStream(Files.newOutputStream(zipFile))) {
            if (Files.isRegularFile(source)) {
                addNewZipEntry(zipOutputStream, source.getParent(), source);
            }
            else if (Files.isDirectory(source)){
                FileManager fileManager = new FileManager(source);
                List<Path> fileNames = fileManager.getFileList();
                for (Path path : fileNames){
                    addNewZipEntry(zipOutputStream, source, path);
                }
            }
            else {
                throw new PathNotFoundException();
            }

        }
    }

    private void addNewZipEntry(ZipOutputStream zipOutputStream, Path filePath, Path fileName) throws Exception{
        try(InputStream inputStream = Files.newInputStream(fileName.resolve(filePath))) {
            ZipEntry zipEntry = new ZipEntry(fileName.getFileName().toString());
            zipOutputStream.putNextEntry(zipEntry);

            copyData(inputStream, zipOutputStream);

            zipOutputStream.closeEntry();
        }
    }

still failing though

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 14:29

line 8: addNewZipEntry(zipOutputStream, source.getParent(), source.getFileName());

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 14:49

Didn't work unfortunately

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 14:52

Also, here's the updated code on pastebin, save me posting it each time

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 14:58

useful

The first one here definitely needs fixing, I added some more things that I see that could be issues (lines from pastebin): This is backwards, it should be: Line 41: try(InputStream inputStream = Files.newInputStream(filePath.resolve(fileName))) fileName is already the file name, it should be: Line 42: ZipEntry zipEntry = new ZipEntry(fileName.toString()); same with: Line 22: addNewZipEntry(zipOutputStream, source.getParent(), source);

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 15:19

I've made the changes and now just failing the last requirement. re your last point, I tried that as well as

addNewZipEntry(zipOutputStream, path.getParent(), path);

which I assumed made more sense, as "source" in this case is the directory, not the file. Either way it didn't work

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 15:47

solution

My bad... I messed up line 22. It should be:

addNewZipEntry(zipOutputStream, source, path);

Anthony Chalk

Level 30 , London, United Kingdom

8 April 2021, 15:51

Thank you!!! Isn't that the same as path.getParent()?

Guadalupe Gagnon

Level 37 , Tampa, United States

8 April 2021, 15:57

useful

no. The FileManager class returns the list of relative paths. That means they don't include the full path, just the path from the start point (which is "source"). So if source was: "C:\\users\me\desktop\zipFile" you get a list of only relative paths that would be something like this: "file1.txt" "folder\file2.txt" Where the full path of those would be pre-fixed with "source", but the relative paths are not. The first thing that addNewZipEntry() does is combine the source and file together.