java.lang.NoClassDefFoundError

[Chris Bremer]

I am getting a runtime error java.lang.NoClassDefFoundError on this line (line 40) FileArray outputFile = new FileArray();
I have never seen this error before and when I researched it the solution were a bit over my head. any suggestions would be appreciated.

import java.util.*;

public class FileArrayDemo
{
    public static void main(String[] args)
    {
        Scanner keyboard = new Scanner(System.in);
        System.out.println("Please enter the file name to write to:");
        String fileName = keyboard.nextLine();
        System.out.println("How many numbers do you want to enter:");
        int arraySize = 0;
        try
        {
            arraySize = keyboard.nextInt();
            if (arraySize < 1)
            {
                throw new InputMismatchException();
            }
        }
        catch (InputMismatchException e)
        {
            System.out.println("Please enter only positive whole numbers");
            System.exit(1);
        }
        int[] array = new int[arraySize];
        for (int i = 0; i < arraySize; )
        {
            System.out.println("Enter next number:");
            try
            {
                array[i] = keyboard.nextInt();
                i++;
            }
            catch (InputMismatchException e)
            {
                System.out.println("Please enter only whole numbers");
                keyboard.nextLine();
            }
        }
        FileArray outputFile = new FileArray();   
        outputFile.writeArray(fileName, array);
    }
}


/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

import java.io.*;

public class FileArray
{
    public FileArray()
    {
    }
    public static void writeArray(String fileName, int[] writeArray)
    {
        DataOutputStream outputFile;   
        try
        {
            outputFile = new DataOutputStream(new FileOutputStream(fileName));
        }
        catch (FileNotFoundException e)
        { 
            System.out.println(e.getMessage());
        }
        System.out.println("Writing data to file...");
        try
        {
            for (int arrayOutIndex : writeArray)
            {
                outputFile.writeInt(arrayOutIndex);
            }
            outputFile.close(); 
        }
        catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
}

[Bear Bibeault]

It means your FileArray class is not in the classpath at run time.

This has little to do with your code, and more to do with how you are running it. So that's what you need to let us know.

[Campbell Ritchie]

And welcome to the Ranch