help me with last condition please

Question about the task

Archiver (part 8)

Java Multithreading, Level 7, Lesson 15

Resolved

"The main method must call the askOperation() method to get the current operation." but i am calling it!

To find out which command the user currently wants to execute, let's add an Operation
askOperation() method to the Archiver class. This method should display a list of available commands and
ask the user to choose one of them. For convenience, we will ask the user to enter the command's number, which is its
ordinal number in the Operation enum. You can get an enum field's ordinal number using the ordinal() method.
Now everything is ready to rewrite the main method using our latest scientific advancements, specifically
the CommandExecutor class and the askOperation() method.
1. Add a public static Operation askOperation() throws IOException method to the Archiver class.
It must: 1.1. Use the ConsoleHelper class's methods
1.2. Ask the user for the number of the desired operation.

Hint:
To display the number of the "Create archive" operation, use: Operation.CREATE.ordinal()

1.3. Return the selected operation.
Example output of the askOperation() method:


Select an operation:0 - Zip files into an archive
1 - Add a file to an archive
2 - Remove a file from an archive
3 - Extract an archive
4 - View the contents of an archive
5 - Exit

2. Rewrite the main() method:
2.1. Declare a local Operation variable
2.2. In a loop, use the askOperation() method to ask for a new value for the variable in step 2.1, and use CommandExecutor.execute() to perform the operation.
2.3. Allow the user to exit the loop by selecting the Operation.EXIT operation
2.4. Wrap the askOperation() and execute(operation) calls in a try-catch block. If a NoSuchZipFileException occurs, use ConsoleHelper to display "You didn't select an archive or you selected an invalid file." If any other exceptions occur, display "An error occurred. Please check the entered data."
2.5. Be sure that the program continues running (continues to a new iteration of the loop) after handling exceptions.
3. Run the program and verify that the "exit" command works.

Requirements:

You need to create a public static Operation askOperation() method in the Archiver class.
The askOperation method should display all of the possible operations and their numbers.
The askOperation method should read the selected operation's number from the keyboard and return it.
Rewrite the main method according to the task conditions.

package com.codegym.task.task31.task3110; import com.codegym.task.task31.task3110.command.Command; import com.codegym.task.task31.task3110.command.ExitCommand; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.nio.file.Path; import java.nio.file.Paths; public class Archiver { public static Operation askOperation() throws IOException { ConsoleHelper.writeMessage("Please type the number of the desired operation:"); ConsoleHelper.writeMessage("0 - Zip files into an archive"); ConsoleHelper.writeMessage("1 - Add a file to an archive"); ConsoleHelper.writeMessage("2 - Remove a file from an archive"); ConsoleHelper.writeMessage("3 - Extract an archive"); ConsoleHelper.writeMessage("4 - View the contents of an archive"); ConsoleHelper.writeMessage("5 - Exit"); int ordinal = ConsoleHelper.readInt(); Operation operation = null; for(Operation op : Operation.values()) { if(op.ordinal() == ordinal) operation = op; } return operation; } public static void main(String[] args) throws Exception { System.out.println("Please enter the full path to the archive (don't forget that the file name is also part of the full path!)."); BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); String fileName = reader.readLine(); String fileToZip = reader.readLine(); Path path = Paths.get(fileName); Path pathToZip = Paths.get(fileToZip); ZipFileManager zipFileManager = new ZipFileManager(path); System.out.println("Please enter the path to the file to be zipped (don't confuse this with the archive file, which we already entered!)."); zipFileManager.createZip(pathToZip); Operation operation; while (true) { try { operation = askOperation(); CommandExecutor.execute(operation); if(operation == Operation.EXIT) break; } catch (NoSuchFieldException 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."); } } ExitCommand exitCommand = new ExitCommand(); exitCommand.execute(); } }

Comments (7)

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dnlklnhfr

Level 30 , Karlsruhe, Germany

12 August 2020, 17:34

1. Your main-method contains a lot of code the validator doesn't want to see (lines 35-48 + 67-68). 2. Try using a do-while-loop instead of the infinite while(true) as already suggested by Roman here: https://codegym.cc/help/3921

Henrique

Level 41 , São Paulo, Brazil

12 August 2020, 17:38

Thanks for you answer! I noticed that and deleted all that stuff. And now I'm having the problem: "If any exception other than a NoSuchZipFileException occurs, then display "An error occurred. Please check the entered data."" But in my mind I AM displaying that. How can I do a do-while loop? I don't know how to do that. I googled and still cannot apply it here. Thanks!

public static void main(String[] args) throws Exception {
    Operation operation = null;

    while (operation != Operation.EXIT) {
        try {
            operation = askOperation();
            CommandExecutor.execute(operation);

            if(operation == Operation.EXIT)
                break;

        } catch (NoSuchFieldException 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.");
        }
    }

    ExitCommand exitCommand = new ExitCommand();
    exitCommand.execute();
}

Henrique

Level 41 , São Paulo, Brazil

12 August 2020, 17:41

I tried this do-while and it didn't work:

Operation operation = null;
do {
    try {
        operation = askOperation();
        CommandExecutor.execute(operation);

        if(operation == Operation.EXIT)
            break;

    } catch (NoSuchFieldException 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);

dnlklnhfr

Level 30 , Karlsruhe, Germany

12 August 2020, 19:06

almost there. just get rid of the duplicate line 7-8 as this is checked already in line 15 :)

Henrique

Level 41 , São Paulo, Brazil

12 August 2020, 19:20

I managed to pass it in some other way. I think I didn't use do-while. Just while(operation != Operation.EXIT) and some other things, like checking if Exception e was an instanceof NoSuchFieldException and then print the message. But the code was automatically changed for the next tasks, so I'm not able to recover my solution to show you. Thanks anyway!

Henrique

Level 41 , São Paulo, Brazil

12 August 2020, 19:22

If someone is stuck in here, here's a possible part of the solution:

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);
}

Dawid Bujnicki Junior Developer

18 October 2021, 17:03

That code above validator did not like for some reason. I solved it by merging catch blocks into one and checking if exception is the one we are looking for.