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Thread: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

  1. #1
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    Default Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Maze.java
     
    import javax.swing.*;
     
    public class Maze
    {
    	public static void main(String[] args)
      {
    	 JFrame mainframe = new JFrame();
    	 mainframe.add(new Board());
    	 mainframe.setTitle("Noah's Game");
    	 mainframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    	 mainframe.setSize(512,512);
    	 mainframe.setLocationRelativeTo(null);
    	 mainframe.setVisible(true);
     
      }
     
    }

    Board.java
    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics;
    import java.awt.event.*;
    import javax.swing.*;
    import java.*;
     
    public class Board extends JPanel implements ActionListener {
    	private Map m;
    	private Timer timer;
    	private Player p;
    	private String Message = "Winner!";
    	private boolean Win = false;
    	private Font font = new Font("Serif", Font.BOLD,48);
     
    	public Board() {
    		timer = new Timer(25, this);
    		timer.start();
    		m = new Map();
    		p = new Player();
    		addKeyListener(new Al());
    		setFocusable(true);
     
    	}
     
    	public void actionPerformed(ActionEvent e) {
    		repaint();
    		if(m.getMap(p.getTileX(), p.getTileY()).equals("f"))
    		{
    			Message = "Winner!";
    			Win = true;
    		}
    	}
     
    	public void paint(Graphics g) {
    		super.paint(g);
     
    		if(!Win){
    		for (int y = 0; y < 16; y++) {
    			for (int x = 0; x < 16; x++) {
     
    				if (m.getMap(x, y).equals("f")) {
    					g.drawImage(m.getFinish(), x * 32, y * 32, null);
    				}
    				if (m.getMap(x, y).equals("g")) {
    					g.drawImage(m.getDirt(), x * 32, y * 32, null);
    				}
     
    				if (m.getMap(x, y).equals("w")) {
    					g.drawImage(m.getWall(), x * 32, y * 32, null);
    				}
    			}
    		}
    		g.drawImage(p.getPlayer(), p.getTileX() * 32, p.getTileY() * 32, null);
    		}
     
    		if(Win){
    		g.setColor(Color.MAGENTA);
    		g.setFont(font);
    		g.drawString(Message, 150, 300);
     
    		}
     
     
     
    	}
     
    	public class Al extends KeyAdapter {
    		public void keyPresed(KeyEvent e) {
     
    			if (e.getKeyCode() == KeyEvent.VK_W) {
    				if (!m.getMap(p.getTileX(), p.getTileY() - 1).equals("w"))
    					;
    				p.move(0, -1);
     
    			}
     
    			if (e.getKeyCode() == KeyEvent.VK_A) {
    				if (!m.getMap(p.getTileX(), p.getTileY() + 1).equals("w"))
    					;
    				p.move(0, 1);
     
    			}
     
    			if (e.getKeyCode() == KeyEvent.VK_S) {
    				if (!m.getMap(p.getTileX() - 1, p.getTileY()).equals("w"))
    					;
    				p.move(-1, 0);
     
    			}
     
    			if (e.getKeyCode() == KeyEvent.VK_D) {
    				if (!m.getMap(p.getTileX() + 1, p.getTileY()).equals("w"))
    					;
    				p.move(1, 0);
     
    			}
     
    		}
     
    		public void keyReleased(KeyEvent e) {
     
    		}
     
    		public void keyTyped(KeyEvent e) {
     
    		}
     
    	}
    }


    Map.java
    import java.util.*;
    import java.awt.*;
    import java.io.*;
     
    import javax.swing.ImageIcon;
     
    public class Map
    {
     
    	private Scanner m;
    	private String 	Map[] = new String[16];
    	private Image dirt ,
    	              wall,
    	             finish;
     
    	public void map()
    	{
    		ImageIcon img = new ImageIcon("C://Noah's World//dirt.png");
    		dirt = img.getImage();
    		img = new ImageIcon("C://Noah's World//wall.png");
    		wall = img.getImage();
    		img = new ImageIcon("C://Noah's World//finish.png");
    		finish = img.getImage();
     
     
    		openFile();
    		readFile();
    		closeFile();
     
    	}
     
    	public Image getFinish()
    	{
    		return finish;
    	}
    	public Image getDirt()
    	{
    		return dirt;
    	}
    	public Image getWall()
    	{
    		return wall;
    	}
     
     
    	public String getMap(int x, int y)
    	{
    			String index = Map[y].substring(x ,x + 1);
    			return index;
    	}
     
    	public void openFile()
    	{
    		try{
    		m = new Scanner(new File("C://Noah's World//Map.txt"));
    		}catch(Exception e)
    		{
    			System.out.println("error loading map");
    		}
    	}
     
    	public void readFile()
    	{
    		while(m.hasNext())
    		{
    			for(int i = 0; i < 14; i++)
    			{
    				Map[i] = m.next();
    			}
    		}
    	}
     
    	public void closeFile()
    	{
    		m.close();
    	}
    }


    Player.ja
    import java.awt.Image;
     
    import javax.swing.ImageIcon;
     
    public class Player {
    	private int tileX, tileY;
    	private Image player;
     
    	public Player() {
     
    		ImageIcon img = new ImageIcon("C://Noah's World//Player.png");
    		player = img.getImage();
     
    		tileX = 1;
    		tileY = 1;
    	}
     
    	public Image getPlayer() {
    		return player;
    	}
     
    	public int getTileX() {
    		return tileX;
    	}
     
    	public int getTileY() {
    		return tileY;
    	}
     
    	public void move(int dx, int dy) {
     
     
    		tileX += dx;
    		tileY += dy;
    	}
    }


    Error Report
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    	at Map.getMap(Map.java:48)
    	at Board.actionPerformed(Board.java:28)
    	at javax.swing.Timer.fireActionPerformed(Timer.java:312)
    	at javax.swing.Timer$DoPostEvent.run(Timer.java:244)
    	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
    	at java.awt.EventQueue.access$000(EventQueue.java:102)
    	at java.awt.EventQueue$3.run(EventQueue.java:662)
    	at java.awt.EventQueue$3.run(EventQueue.java:660)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    	at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
    	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    	at Map.getMap(Map.java:48)
    	at Board.paint(Board.java:42)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paint(JComponent.java:1063)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paint(JComponent.java:1063)
    	at javax.swing.JLayeredPane.paint(JLayeredPane.java:585)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paintToOffscreen(JComponent.java:5228)
    	at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1482)
    	at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1413)
    	at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    	at javax.swing.JComponent.paint(JComponent.java:1040)
    	at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:39)
    	at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:78)
    	at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:115)
    	at java.awt.Container.paint(Container.java:1967)
    	at java.awt.Window.paint(Window.java:3877)
    	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:781)
    	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    	at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    	at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    	at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
    	at java.awt.EventQueue.access$000(EventQueue.java:102)
    	at java.awt.EventQueue$3.run(EventQueue.java:662)
    	at java.awt.EventQueue$3.run(EventQueue.java:660)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    	at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
    	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    	at Map.getMap(Map.java:48)
    	at Board.paint(Board.java:42)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paint(JComponent.java:1063)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paint(JComponent.java:1063)
    	at javax.swing.JLayeredPane.paint(JLayeredPane.java:585)
    	at javax.swing.JComponent.paintChildren(JComponent.java:887)
    	at javax.swing.JComponent.paintToOffscreen(JComponent.java:5228)
    	at javax.swing.RepaintManager$PaintManager.paintDoubleBuffered(RepaintManager.java:1482)
    	at javax.swing.RepaintManager$PaintManager.paint(RepaintManager.java:1413)
    	at javax.swing.RepaintManager.paint(RepaintManager.java:1206)
    	at javax.swing.JComponent.paint(JComponent.java:1040)
    	at java.awt.GraphicsCallback$PaintCallback.run(GraphicsCallback.java:39)
    	at sun.awt.SunGraphicsCallback.runOneComponent(SunGraphicsCallback.java:78)
    	at sun.awt.SunGraphicsCallback.runComponents(SunGraphicsCallback.java:115)
    	at java.awt.Container.paint(Container.java:1967)
    	at java.awt.Window.paint(Window.java:3877)
    	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:781)
    	at javax.swing.RepaintManager.paintDirtyRegions(RepaintManager.java:728)
    	at javax.swing.RepaintManager.prePaintDirtyRegions(RepaintManager.java:677)
    	at javax.swing.RepaintManager.access$700(RepaintManager.java:59)
    	at javax.swing.RepaintManager$ProcessingRunnable.run(RepaintManager.java:1621)
    	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
    	at java.awt.EventQueue.access$000(EventQueue.java:102)
    	at java.awt.EventQueue$3.run(EventQueue.java:662)
    	at java.awt.EventQueue$3.run(EventQueue.java:660)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    	at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
    	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)


  2. #2
    Super Moderator curmudgeon's Avatar
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Your Map array never gets filled. That's likely because the Map class has no constructor. Give it a valid constructor and this problem may well be fixed.

    Remember that constructors have no return type and that Java is case sensitive, in other words map != Map.

    Also you should edit your code so that your identifier naming conforms with Java naming standards: class names begin with upper case letters while variable and method names begin with lower case letters. Else your code will be very difficult to read and understand.

  3. #3
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    i added this as the constructer

    public Map()
    	{
    		ImageIcon img = new ImageIcon("C://Noah's World//dirt.png");
    		dirt = img.getImage();
    		img = new ImageIcon("C://Noah's World//wall.png");
    		wall = img.getImage();
    		img = new ImageIcon("C://Noah's World//finish.png");
    		finish = img.getImage();
     
     
    		openFile();
    		readFile();
    		closeFile();
     
    	}


    but im still gettting errors
    Exception in thread "main" java.util.NoSuchElementException
    	at java.util.Scanner.throwFor(Scanner.java:907)
    	at java.util.Scanner.next(Scanner.java:1416)
    	at Map.readFile(Map.java:68)
    	at Map.<init>(Map.java:27)
    	at Board.<init>(Board.java:19)
    	at Maze.main(Maze.java:9)
    Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
    	at Board.actionPerformed(Board.java:28)
    	at javax.swing.Timer.fireActionPerformed(Timer.java:312)
    	at javax.swing.Timer$DoPostEvent.run(Timer.java:244)
    	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
    	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:701)
    	at java.awt.EventQueue.access$000(EventQueue.java:102)
    	at java.awt.EventQueue$3.run(EventQueue.java:662)
    	at java.awt.EventQueue$3.run(EventQueue.java:660)
    	at java.security.AccessController.doPrivileged(Native Method)
    	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    	at java.awt.EventQueue.dispatchEvent(EventQueue.java:671)
    	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

  4. #4
    Super Moderator Norm's Avatar
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Exception in thread "main" java.util.NoSuchElementException
    at java.util.Scanner.throwFor(Scanner.java:907)
    at java.util.Scanner.next(Scanner.java:1416)
    at Map.readFile(Map.java:68)
    At line 68 the code calls the Scanner class's next() method. The method throws: NoSuchElementException
    Read the API doc for a description of what that means.

    Basically you need to test if there is something to be read before trying to read it. The Scanner class has some methods: (names begin with has) that will tell you if there is something available to read so you can skip calling next() when there is no more to read.
    If you don't understand my answer, don't ignore it, ask a question.

  5. #5
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Quote Originally Posted by Norm View Post
    At line 68 the code calls the Scanner class's next() method. The method throws: NoSuchElementException
    Read the API doc for a description of what that means.

    Basically you need to test if there is something to be read before trying to read it. The Scanner class has some methods: (names begin with has) that will tell you if there is something available to read so you can skip calling next() when there is no more to read.
    I don't understand how to put this method into my code. im still a beginner. If you could tell me where it would go into the code and/or what to put. Thanks!

  6. #6
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Before calling next() you need to make sure there is data to be read. Call the hasNext method first to determine if there is anything to read. If hasNext() returns false, do not call the next() method.
    If you don't understand my answer, don't ignore it, ask a question.

  7. #7
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Quote Originally Posted by Norm View Post
    Before calling next() you need to make sure there is data to be read. Call the hasNext method first to determine if there is anything to read. If hasNext() returns false, do not call the next() method.
    i have added has next so it looks like this :
    public void readFile()
    	{
    		while(m.hasNext())
    		{
    			for(int i = 0; i < 14; i++)
    			{
    				Map[i] = m.next();
    			}
    		}
    	}

    but i get the same error i think i have not implemented it correctly if you know how to fix this then please help me thx

  8. #8
    Super Moderator Norm's Avatar
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    You must call hasNext() for each time that you call next(). The posted code only calls it once before the inner loop calls it 14 times.
    If you don't understand my answer, don't ignore it, ask a question.

  9. #9
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    How do i write that in code??

  10. #10
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    Default Re: Exception in thread "AWT-EventQueue-0" at Map.getMap(Map.java:48)

    Some thing like this:
    while(input.hasNext() {
      data = input.next();
     // more stuff here
    }
    If you don't understand my answer, don't ignore it, ask a question.

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