Erreur de lecture d'un tableau multidimensionnel

Version imprimable

Salut à tous !

J'ai un petit bug de lecture dans un programme qui se compile parfaitement (une map pour un jeu 2D). Quand j'arrive à la ligne en gras

Code:

System.out.println(tab_map[i][j]);

, j'ai un énorme message d'erreur : "Exeption in thread "AWT-Queue-0" java.lang.NullPointerException" etc...
NB : je bosse avec Java sans IDE ni aucun logiciel : juste un notepad amélioré et la console de commande (l'obligation ne vient pas de moi :whistle)...

Code:

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import javax.swing.*;
import java.awt.*;

public class PanneauJeu1 extends JPanel 
	{
	
	public int tab_map[][];

	
	// constructeur
        public PanneauJeu1()	{
        
          int tab_map[][] = {
          {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
          };



        }
        
        
	
	public void paintComponent(Graphics g) 
		{
		super.paintComponent(g);
		
		
		for(int i = 0; i<18; i++)
      {
       for(int j = 0; j<26; j++)
          {
          System.out.println(tab_map[i][j]);
          //if(tab_map[i][j] == 1) {
          // g.drawImage(Toolkit.getDefaultToolkit().getImage("images/game/tile_arbres.jpg"),j*30+7,i*30+17,this);
          //} else if(tab_map[i][j] == 0) {
          //g.drawImage(Toolkit.getDefaultToolkit().getImage("images/game/tile_herbe1.jpg"),j*30+7,i*30+17,this);
          //}
          
          }
      }
      
      
		
		
		}
		
		
		}

Merci d'av',
Bonne soirée =)
Val'

10/06/2009, 19h58
william44290

as tu essayé d'inversé ton i et ton j ?
10/06/2009, 20h01
Celeborn

C'est normal ton tableau tab_map (attribut de class est null). Dans ton constructeur c'est une variable locale (qui a le même nom que ton attribut) que tu initialises.

P.S. Attention à la nomenclature de tes variables littleCamel!
10/06/2009, 20h02
Celeborn

Citation:

Envoyé par william44290

as tu essayé d'inversé ton i et ton j ?

Cela aurait provoqué une indexOut...Exception
10/06/2009, 20h03
tchize_

vu que ton tab_map est public, vérifie que t'as pas du code ailleurs qui le met à null.

comme ça ça marche

Code:

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import javax.swing.*;
import java.awt.*;
 
public class PanneauJeu1 extends JPanel 
	{
 
	public int[][] tab_map;
 
 
	// constructeur
        public PanneauJeu1()	{
 
          this.tab_map= new int[][]{
          {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1},
          {1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1},
          };
 
 
 
        }
 
 
 
	public void paintComponent(Graphics g) 
		{
		super.paintComponent(g);
 
 
		for(int i = 0; i<18; i++)
      {
       for(int j = 0; j<26; j++)
          {
          System.out.println(tab_map[i][j]);
          //if(tab_map[i][j] == 1) {
          // g.drawImage(Toolkit.getDefaultToolkit().getImage("images/game/tile_arbres.jpg"),j*30+7,i*30+17,this);
          //} else if(tab_map[i][j] == 0) {
          //g.drawImage(Toolkit.getDefaultToolkit().getImage("images/game/tile_herbe1.jpg"),j*30+7,i*30+17,this);
          //}
 
          }
      }
 
 
 
 
		}
 
		}

10/06/2009, 22h17
Valenten

Okay, je venais de trouver avec l'indication de Celeborn ;)
Merci à tous, bonne soirée :p

Val =)
10/06/2009, 22h20
michel.di

merci bonne soirée a toi aussi