I'm kind of stuck in a java project. I have this issue and I don't know how to work this out.
Basically I create a robot which goes from object to object listing them. Objects don't move but robots (agents in my code) do.
Some of the variables I use come from the FinalProject Class which is my main class.
I create a matrix of ArrayLists as my world and I want to add objects and agents to it. They both inherit from the class Entity. My problem is I don't know how to name them differently as I add them to the matrix. Here's my World class:
package finalproject;
import java.util.*;
public class World {
protected int cord_x , cord_y , agent_num , object_num , numero_x , numero_y, conta = 1, i = 0;
protected String op, nome;
protected String [] tipos;
public World (int cord_x, int cord_y, int agent_num, int object_num , String op){
this.cord_x = cord_x;
this.cord_y = cord_y;
this.agent_num = agent_num;
this.object_num = object_num;
this.op = op;
ArrayList<Entity>[][] mundo = (ArrayList<Entity>[][])new ArrayList<?>[cord_x][cord_y];
if (op.equals("s")){
gera_agent(agent_num , mundo);
gera_object(object_num, mundo);
}
}
private ArrayList<Entity>[][] gera_agent(int num , ArrayList<Entity>[][] mundo){
String [] cores = {"vermelho", "azul", "verde", "preto"};
String [] formas = {"triangulo", "quadrado", "retangulo", "losango"};
String [] estrategias = {"random", "hamming", "closest"};
i=0;
while (i<num){
int numeroY = new Random().nextInt(cord_x);
int numeroX = new Random().nextInt(cord_y);
int rcores = new Random().nextInt(cores.length);
int rformas = new Random().nextInt(formas.length);
int restrategias = new Random().nextInt(estrategias.length);
String cor = (cores[rcores]);
String forma = (formas[rformas]);
String estrategia = (estrategias[restrategias]);
nome = "Agente" + Integer.toString(conta);
Entity nome = new Agent(nome, cor, forma, numeroX, numeroY, conta, estrategia, FinalProject.raio);
mundo[numeroX][numeroY].add(nome);
conta++;
i++;
}
return mundo;
}
private ArrayList<Entity>[][] gera_object(int num , ArrayList<Entity>[][] mundo){
String [] cores = {"vermelho", "azul", "verde", "preto"};
String [] formas = {"triangulo", "quadrado", "rectangulo", "losango"};
if (FinalProject.op1.equals("planeta")){
tipos = new String[] {"rocha", "alien", "caratera"};
}
else if (FinalProject.op1.equals("catastrofe")){
tipos = new String []{"sobrevivente", "morto", "escombros"};
}
else if (FinalProject.op1.equals("domesticos")){
tipos = new String [] {"mesa", "cadeira", "vassora"};
}
i=0;
while (i<num){
int numeroX = new Random().nextInt(cord_x);
int numeroY = new Random().nextInt(cord_y);
int rcores = new Random().nextInt(cores.length);
int rformas = new Random().nextInt(formas.length);
int rtipo;
rtipo = new Random().nextInt(tipos.length);
String cor = (cores[rcores]);
String forma = (formas[rformas]);
String tipo = (tipos[rtipo]);
nome = "Object" + Integer.toString(conta);
Entity nome = new Object(nome, cor, forma, numeroX, numeroY, conta, estrategia, FinalProject.raio);
mundo[numeroX][numeroY].add(nome);
conta++;
i++;
}
return mundo;
}
Basically when I am doing this: Entity nome = new Agent(nome, cor, forma, numeroX, numeroY, conta, estrategia, FinalProject.raio); mundo[numeroX][numeroY].add(nome); - which is stupid. Do I need to name the object I want to add in the matrix? if I do, how do I do it?
at some point in my name I create the world using some input variables this way:
World mundo = new World(W_x , W_y , num_ag , num_ob , op2);
My Entity Class:
package finalproject;
import java.util.ArrayList;
public abstract class Entity {
protected String name;
protected String color;
protected String shape;
protected int xCoordenate;
protected int yCoordenate;
protected int id;
public Entity (String name, String color , String shape , int xCoordenate , int yCoordenate , int id){
this.name = name;
this.color = color;
this.shape = shape;
this.xCoordenate = xCoordenate;
this.yCoordenate = yCoordenate;
this.id = id;
}
I think the problem in your code is that you are not initializing the ArrayList before it's use e.g. One I have written in the snippet below:: mundo[i][j] = new ArrayList<Integer>();
int cord_x = 6, cord_y = 5, num = 10;
ArrayList<Integer>[][] mundo = (ArrayList<Integer>[][])
new ArrayList<?>[cord_x][cord_y];
for(int i = 0; i < cord_x; i++){
for(int j = 0; j < cord_y; j++){
//***Instantiate the ArrayList---This is required***
mundo[i][j] = new ArrayList<Integer>();
for(int k = 0; k < num; k++){
// Add the elements in the array list
mundo[i][j].add(new Integer(i+j+k));
}
}
}
//Check the elements
for(int i = 0; i < cord_x; i++){
for(int j = 0; j < cord_y; j++){
for(int k = 0; k < num; k++){
// prints the elements
System.out.println("mundo["+i+"]["+j+"]- place "
+k+" Element == " +mundo[i][j].get(k));
}
}
}
The above snippet populates the elements the first iteration and prints them in the second as:
mundo[0][0]- place 0 Element == 0
mundo[0][0]- place 1 Element == 1
mundo[0][0]- place 2 Element == 2
mundo[0][0]- place 3 Element == 3
......
I think you can adapt two approaches in your code.
Before mundo[numeroX][numeroY].add(nome); line add a check to see initialization as below
if(mundo[numeroX][numeroY] == null){
mundo[numeroX][numeroY] = new ArrayList<Entity>();
}
Before the while loop, you can initialize all the array list elements together by putting a initialization snippet as below:
for(int i = 0; i < cord_x; i++){
for(int j = 0; j < cord_y; j++){
mundo[i][j] = new ArrayList<Entity>(); // <-- Instantiate the ArrayList
}
}