2D Tile Game Lag (Caused By Loop) - Rendering All Tile Rectangles

So the following is my code for the Terrian Generation of my game, however the way i have it rendering all the tile rectangles as opposed to just rendering whats visable on my JFrame causes lots of lag.

These are the variables and Rectangles inside _TerrianGen.class

//CHUNK
static int chunkx =2048;
static int chunky =2048;
 
//RECTANGLES
public static Rectangle[][] tile = new Rectangle[64][64];
static int[][] blockType = new int[64][64];
//0=Grass 1=Dirt 2=Stone 10=Brick 11=Coal 12=Iron 21=Gold 22=Diamond -1=null

This is the Init() code

for (int x =0; x < chunkx-32; x+=32){
for (int y=0; y < chunky-32; y+=32){
tile[y/32][x/32] = new Rectangle(x, y, 32, 32);
blockType[y/32][x/32] = -1;

[Code] ....