reorganized code

Board.java

@@ -0,0 +1,23 @@
+import java.awt.*;
+
+public class Board {
+  Piece[][] board;
+
+  public Board() {
+    board = new Piece[8][8];
+    for (int i = 0; i <= 7; i++) {
+      board[i][2] = new Pawn(i + 1, 2, "Black");
+    }
+    for (int i = 0; i <= 7; i++) {
+      board[i][7] = new Pawn(i + 1, 7, "Black");
+    }
+  }
+
+  public void draw(Graphics g) {
+    for (Piece[] row : board) {
+      for (Piece p : row) {
+        if (p != null) p.draw(g);
+      }
+    }
+  }
+}

Chess.java

@@ -1,15 +1,12 @@
 import java.awt.*;
 import java.awt.Color;
 import java.awt.event.*;
-import java.util.ArrayList;
 import javax.swing.*;
-import javax.swing.border.*;
 
 public class Chess extends JPanel implements ActionListener {
 
   // pieces stuff
-  ArrayList<Piece> white;
-  ArrayList<Piece> black;
+  Board board;
 
   // game vars
   int boardWidth, boardHeight;
@@ -25,15 +22,7 @@ public class Chess extends JPanel implements ActionListener {
     setBackground(Color.WHITE);
     setFocusable(true);
 
-    white = new ArrayList<>();
-    black = new ArrayList<>();
-
-    for (int i = 0; i <= 7; i++) {
-      white.add(new Pawn(i + 1, 2, "White"));
-    }
-    for (int i = 0; i <= 7; i++) {
-      black.add(new Pawn(i + 1, 7, "Black"));
-    }
+    board = new Board();
 
     gameTimer = new Timer(200, this);
 
@@ -54,8 +43,7 @@ public class Chess extends JPanel implements ActionListener {
     }
 
     // draw pieces
-    for (Piece p : white) p.draw(g);
-    for (Piece p : black) p.draw(g);
+    board.draw(g);
   }
 
   public void paintComponent(Graphics g) {