got error in java.lang.NullPointerExceptions

Question

i had a problem of my program it is process completed but it has runtime exception the java.lang.NullPointerException. Anyone can help me ? this is my code so far .

  import javax.swing.*;
import java.lang.Character;
import java.io.*;
public class CoproHW
{
    public static String c;
    public static int NOc;
    public static String vince;
    public static void main(String args [])throws IOException
    {

        String vince = JOptionPane.showInputDialog("Enter Your File path :");
         c = JOptionPane.showInputDialog("Enter a character");

        briefer();
    }
    public static void briefer()
    {

        for(int v = 1; v<c.length(); v++)
        {
            char x = c.charAt(v);
            if(Character.isSpaceChar(x))
            {
                NOc++;
            }


            char z = c.charAt(v);
            if(Character.isLetter(z))
            {
                NOc++;
            }
        }

        panty();
    }
    public static void panty()
    {
        File file = new File(vince);

        if(!file.exists())
        {
            JOptionPane.showMessageDialog(null,"Wrong file path !");
        }
        else
        {
            JOptionPane.showMessageDialog(null, "The Number of Characters in "+ c +" is "+ NOc);

            try
            {
                RandomAccessFile gui = new RandomAccessFile(file," ");

                gui.writeBytes("The number of Characters in "+ c + " is " +NOc);
                gui.close();
            }

            catch(IOException m)
            {
                System.out.print(m.getMessage());
                System.exit(0);
            }
        }
    }
}

NOc in an int here, so that cannot be the source of the exception. Please post the stacktrace. I think your intent is to do File file = new File(c); rather than File file = new File(vince); — Kishore
– Kishore, Commented Feb 7, 2014 at 3:46

Weibo Li · Accepted Answer · 2014-02-07 03:45:23Z

2

Because you didn't assign value to your global vince variable. Instead, you assigned the expected value to a local variable:

String vince = JOptionPane.showInputDialog("Enter Your File path :");

Modify the code to:

vince = JOptionPane.showInputDialog("Enter Your File path :");

And then it will work.

answered Feb 7, 2014 at 3:45

Weibo Li

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Comments

irvana · Accepted Answer · 2014-02-07 03:51:36Z

0

Remove the String at the main method.

vince = JOptionPane.showInputDialog("Enter Your File path :");

It is a global variable you have been declared.

answered Feb 7, 2014 at 3:51

irvana

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2 Comments

takendarkk Over a year ago

I'm just curious, did this add anything that wasn't already in the answer that was provided and has upvotes?

irvana Over a year ago

Ya, i realize this thing after i post my answer. Dont know there is another answer because when i read this post, there is no answer posted.

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