java - Updating only items near the player -

since hit out of memory error, have been trying improve code items closest player update , not @ once, overloading system.

firstly world[][] multi-dimensional array holding random integer values inside, being: 0 (nothing), 1(star), 2(planet).

next take world[][] , individually create each planet , star own values in bodymanager class

that , until started adding features caused overload in memory. changed code nearby area scanned , when star found (since planets form around stars solar system) bodymanager class called , creates planets around star star itself.

i running types of issues trying method (eg. stars , planets not render, out of bounds errors world[][] etc.). seeking best method stop memory overloads loading map @ manageable pace. if think current approach on right track having problems loop in update() method running , not updating surroundings properly.

finally, there better way? if yes, please point me in right direction.

otherwise how can fix issues loop , getting items render?

please notify me if more information needed!

update , render methods in world class (where bodymanager called from)

// bodymanager constructor called earlier  public void update()     {         playerx = (int) entitymanager.getplayer().getx();         playery = (int) entitymanager.getplayer().gety();          (int x=(playerx - 30) / bodymanager.tile_width; x<(playerx + 31) / bodymanager.tile_width; x++)         {             (int y=(playery - 30) / bodymanager.tile_height; y<(playery + 31) / bodymanager.tile_height; y++)             {                 system.out.println(x);                 if (playerx < 0 || playerx > width || playery < 0 || playery > height)                     break;                 else if (world[x][y] == 1)                 {                     bodymanager.initbody(x, y);                 }             }         }          entitymanager.update();     }  public void render(graphics g)     {         int xstart = (int) math.max(0, handler.getgamecamera().getxoffset() / bodymanager.tile_width);         int xend = (int) math.min(width, (handler.getgamecamera().getxoffset() + handler.getwidth()) / bodymanager.tile_width + 1);         int ystart = (int) math.max(0, handler.getgamecamera().getyoffset() / bodymanager.tile_height);         int yend = (int) math.min(height, (handler.getgamecamera().getyoffset() + handler.getheight()) / bodymanager.tile_height + 1);          (int y=ystart; y<yend; y++)         {             (int x=xstart; x<xend; x++)             {                 bodymanager.render(g);             }         }         entitymanager.render(g);     } 

bodymanager class

public class bodymanager  {     //static     public final static int tile_width = 20, tile_height = 20;      //class     private handler handler;      private int[][] world;      private map<integer, arraylist<bodies>> map;      public bodymanager(handler handler, int[][] world)     {         this.handler = handler;         this.world = world;          map = new hashmap<>();         map.put(1, new arraylist<>()); //star         map.put(2, new arraylist<>()); //planet     }      public void initbody(int starx, int stary)     {         system.out.println("solar sytem initialized");          map.get(1).add(new star(                 handler,                 starx,                 stary,                 randint(512, 1024)                 ));          (int x=(starx-6); x<(starx+7); x++)         {             (int y=(stary - 6); y<(stary+7); y++)             {                 if (world[x][y] == 2)                 {                     map.get(2).add(new planet(                             handler,                             x,                             y,                             randint(256, 512),                             randfloat(0, 4),                             randint(0, 360)                             ));                 }             }         }     }      public void update()     {         (arraylist<bodies> bodies : map.values())         {              (int = 0; i<bodies.size(); i++)              {                  bodies b = bodies.get(i);                  b.update();              }         }     }      public void render(graphics g)     {         (arraylist<bodies> bodies : map.values())         {             (bodies b : bodies)             {                 b.render(g);             }         }     }      public float randfloat(int min, int max)     {         random rand = new random();         float randfloat = min + (max - min) * rand.nextfloat();         return randfloat;     }      public int randint (int min, int max)     {         random rand = new random();         int randint = rand.nextint((max - min) + 1) + min;         return randint;     } }