CODEWITHSUNDEEP
javamultithreadinggraphicsappletstack-overflow
rupinderjeet
rupinderjeet

Reputation: 2838

StackOverFlowException while filling color using Graphics - Code Included

I want to fill an applet with blue color. I am doing this using paint(Graphics g) method. While filling the applet, i get StackOverFlowException after 8-10 seconds. I want to get rid of it. Please suggest me what to do or correct me if i am doing wrong. I asked someone about this, he said it store locations and removing them later, so that stack is always nearly empty. Please help me.

Code:

import java.applet.Applet;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;

public class Flooding extends Applet
{
    boolean[][] mark;
    boolean justOnce = true;

    @Override
    public void init()
    {
        mark = new boolean[800][600];

        this.setSize(100, 500);
        this.setPreferredSize(new Dimension(100, 500));
        this.setVisible(true);
    }

    @Override
    public void start()
    {
        setBackground(Color.WHITE);
        setForeground(Color.BLACK);
    }

    @Override
    public void paint(Graphics g)
    {
        if(justOnce)
        {
            super.paint(g);
            justOnce = false;
        }

        for (int row=0; row<500; row++)
        {
            for (int col=0; col<100; col++) 
            {
                flood(mark, row, col, g);
            }
        }
    }

    private static void sleep(int msec)
    {
        try 
        {
            Thread.currentThread().sleep(msec);
        }
        catch (InterruptedException e) { }
    }

    public void flood( boolean[][] mark, int row, int col, Graphics g)
    {
        if (row < 0) return;
        if (col < 0) return;
        if (row > 100) return;
        if (col > 500) return;

        if (mark[row][col]) return;

        g.setColor(Color.BLUE);
        g.drawLine(row, col, row, col);

        mark[row][col] = true;

        repaint();
        sleep(1);

        flood(mark, row - 1, col, g);
        flood(mark, row, col, g);
        flood(mark, row + 1, col, g);
        flood(mark, row-1, col-1, g);
        flood(mark, row, col-1, g);
        flood(mark, row+1, col-1, g);
        flood(mark, row-1, col + 1, g);
        flood(mark, row, col + 1, g);
        flood(mark, row+1, col + 1, g);
    }
}

Upvotes: 0

Views: 67

Answers (1)

Axel
Axel

Reputation: 14169

Look at your code: first call to flood() is with coordinates (0, 0) which later calls flood() with coordinates (1, 0) which calls flood()... With your dimensions, you get to a recursion 500 levels deep. Change your code to not using recursion.

(You can of course increase the stack size with -Xss, but your code is broken, so fix that instead.)

Upvotes: 1

Related Questions