public void initGraph(String path){
            
            BufferedReader file ;
            String line;
            String name, id;
            int y = 0;
            try
            {
                file = new BufferedReader(new FileReader(path)) ;
                while ((line = file.readLine()) != null) 
                {
                    for(int i = 0; i < line.length(); i++){

                        id = (i + " : " + y + " : ");
                        if(line.charAt(i) == ' '){
                            name = "void";
                            this.registerNode(new Node(id, name));
                        }else if(line.charAt(i) == 'G'){
                            name = "grass";
                            this.registerNode(new Node(id, name));
                        }else if(line.charAt(i) == 'A'){
                            name = "end";
                            this.registerNode(new Node(id, name));
                        }else if(line.charAt(i) == 'D'){
                            name = "start";
                            this.registerNode(new Node(id, name));
                        }else{
                            name = "wall";
                            this.registerNode(new Node(id, name));
                        }                            
                    }
                    y++;
                }
                file.close();
            }//try
            catch (NullPointerException a)
            {
                    System.out.println("Erreur : pointeur null");
            }
            catch (IOException a) 
            {
                    System.out.println("Problème d'IO  en lecture");
            }
        }