Null Pointer Exception When no value is null

Question

I have the following code:

import java.io.File;

// Example of a BookStore main-class using CommandReader to read commands from input files.

public class BookStore {
    //Declarations
    String title;
    String seller;
    int price;

    public static void main(String[] args) throws BookStoreException {

        ListMultiIndex mi = new ListMultiIndex();   
        File file = new File ("Commands/commands_1_adds.txt");
        CommandReader reader = new CommandReader(file);
        String add = "add";
        String remove = "remove";
        while (reader.hasNext()){
            String [] command = reader.next();
            if((add).equals(command[0])){
               mi.add(command[1], command[2],Integer.parseInt(command[3])); 
               System.out.println("Book Added:");
               System.out.println("Title - " + command[1]);
               System.out.println("Seller - " + command[2]);
               System.out.println("Price - £" + command[3]);
               System.out.println("");

            }
            else if(command[0].equals(remove)){
                BookItem book = new BookItem(command[1], command[2], Integer.parseInt(command[3]));
                mi.remove(book);
                System.out.println("Book Removed:");
                System.out.println("Title - " + command[1]);
                System.out.println("Seller - " + command[2]); 
                System.out.println("Price - " + command[3]);
            }
            else System.out.println("Error:Retype the command, you've spelt 'add' or 'remove' wrong");
        }

    }

}

I keep getting Null Pointer Exception at: if((add).equals(command[0]))

Any help Appreciated, Thanks

The problem originates at `String[] command = reader.next();` — OneCricketeer, Oct 22 '15 at 20:43
Possible duplicate of [What is a Null Pointer Exception, and how do I fix it?](http://stackoverflow.com/questions/218384/what-is-a-null-pointer-exception-and-how-do-i-fix-it) — Kick Buttowski, Oct 22 '15 at 20:44
Command reader is what reads in the commands from the text file. — ally3601, Oct 22 '15 at 20:50
the input is of the format "add 'book title' seller price' this is from a text file — ally3601, Oct 22 '15 at 21:35

score 0 · Answer 1 · edited Oct 22 '15 at 20:43

0

Have you checked if command are null?

if(command != null && add.equals(command[0])){ ... }

edited Oct 22 '15 at 20:43

Kick Buttowski

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answered Oct 22 '15 at 20:42

caioquirino

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Yup. Could be due to unexpected line terminators. – Erick G. Hagstrom Oct 22 '15 at 20:43
i've tried this but now it just prints out the error else statement at the bottom – ally3601 Oct 22 '15 at 20:47

Null Pointer Exception When no value is null

1 Answers1