Question

I’m making a text-based, menu driven program which uses the scanner class to take in both ints and strings. The ints correspond to the menu options, while the strings are used to take in user-input.

private static Scanner userInput = new Scanner(System.in);

public static void main(String[] args)
{
    //Will be used to initiate the while-loop
    int start = 1;

    while(start == 1)
    {
        System.out.print(Messages.printMenu());
        **int choice = new Integer(userInput.nextLine());**

        switch(choice)
        {
            case 1:

                System.out.println(Messages.askForAuthor());
                String author = userInput.nextLine();

                System.out.println(Messages.askForRecepName());
                String recepName = userInput.nextLine();

                System.out.println(Messages.askForEmailAdd());
                String recepEmail = userInput.nextLine(); 

                System.out.println(Messages.askForSubject());
                String subject = userInput.nextLine();

                System.out.println(Messages.askForTextBody());
                String textBody = "";
                ***while(!userInput.hasNext("end") && !userInput.hasNext("END"))***
                {
                    textBody +=  userInput.nextLine() + "\n";
                }

                System.out.println(author);
                System.out.println(recepName);
                System.out.println(recepEmail); 
                System.out.println(subject);
                System.out.println(textBody);
                break;

The parts surrounded by “**” is where the problem occurs. The program runs just fine during the first run, but when it goes into the while loop again for the second time, it causes a type mismatch error because “end”/”END” is still in the Scanner’s stack(I’m guessing it’s a stack) and choice looks for an int.

Here’s the output:

Document Storage System Menu
============================
1 - Create and store an e-mail
2 - Create and store a memo
3 - Create and store a report
4 - Display a document
5 - List all active documents
6 - List all archived documents
7 - Locate documents containing a specific word or phrase
8 - Archive a document
9 - Retrieve a document from the archive
10 - Clear the archive
99 - Quit

Enter your choice: 1
Please enter author: 
Agent Smith
Please enter the recipient's name: 
Neo
Please enter the recipient's e-mail address: 
[e-mail]
Please enter the subject: 
Notification for Eviction!
Please enter Enter text body (type END on separate line to stop): 
All your base are belong to us
end
Agent Smith
Neo
[e-mail]
Notification for Eviction!
All your base are belong to us

Document Storage System Menu
============================
1 - Create and store an e-mail
2 - Create and store a memo
3 - Create and store a report
4 - Display a document
5 - List all active documents
6 - List all archived documents
7 - Locate documents containing a specific word or phrase
8 - Archive a document
9 - Retrieve a document from the archive
10 - Clear the archive
99 - Quit

Enter your choice: Exception in thread "main" java.lang.NumberFormatException: For input string: "end"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.Integer.parseInt(Integer.java:449)
    at java.lang.Integer.<init>(Integer.java:660)
    at proj4.Project4.main(Project4.java:20)***

Answer 1

You should be able to do this:

while(!userInput.hasNext("end") && !userInput.hasNext("END"))
{
    textBody +=  userInput.nextLine() + "\n";
}
userInput.nextLine();

Since at this point you know that either “end” or “END” is still waiting in the Scanner, you can just read the next line and do nothing with it. There are still issues about failing more gracefully if the wrong input is given, but this should solve the given problem.