Added Move Validaity

Bishop.java

 public class Bishop extends Piece{
-  public Bishop(char x, int y, String name){
-    super(x, y, name);
+  public Bishop(char x, int y, boolean color, String name){
+    super(x, y, color, name);
+  }
+
+  public boolean canMove(char x, int y){ // Ignore the presence of other pieces
+    if( Math.abs(this.x - x) / Math.abs(this.y - y) == 1 ){
+
+      return true;
+    }
+    return false;
+  }
+
+  public static boolean canMove(Piece p, char x, int y){ // Ignore the presence of other pieces
+    if( Math.abs(p.x - x) / Math.abs(p.y - y) == 1 ){
+
+      return true;
+    }
+    return false;
   }
 }

Board.java

@@ -13,56 +13,56 @@ public class Board{
     // White Players
     //  Pawns
     for(char ch = 'A'; ch < 'I'; ch++){
-      Pawn newPawn = new Pawn(ch, 2, "WP");
+      Pawn newPawn = new Pawn(ch, 2, true, "WP");
       this.whitePieces.add(newPawn);
     }
     //  Rook
     for(char ch = 'A'; ch < 'I'; ch += 7){
-      Rook newRook = new Rook(ch, 1, "WR");
+      Rook newRook = new Rook(ch, 1, true, "WR");
       this.whitePieces.add(newRook);
     }
     //  Knight
     for(char ch = 'B'; ch < 'H'; ch += 5){
-      Knight newKnight = new Knight(ch, 1, "WN");
+      Knight newKnight = new Knight(ch, 1, true, "WN");
       this.whitePieces.add(newKnight);
     }
     //  Bishop
     for(char ch = 'C'; ch < 'G'; ch += 3){
-      Bishop newBishop = new Bishop(ch, 1, "WB");
+      Bishop newBishop = new Bishop(ch, 1, true, "WB");
       this.whitePieces.add(newBishop);
     }
     //   Queen
-    Queen whiteQueen = new Queen('E', 1, "WQ");
+    Queen whiteQueen = new Queen('E', 1, true, "WQ");
     this.whitePieces.add(whiteQueen);
     //  King
-    King whiteKing = new King('D', 1, "WK");
+    King whiteKing = new King('D', 1, true, "WK");
     this.whitePieces.add(whiteKing);
     // Black Players
     //  Pawns
     for(char ch = 'A'; ch < 'I'; ch++){
-      Pawn newPawn = new Pawn(ch, 7, "BP");
+      Pawn newPawn = new Pawn(ch, 7, false, "BP");
       this.blackPieces.add(newPawn);
     }
     //  Rook
     for(char ch = 'A'; ch < 'I'; ch += 7){
-      Rook newRook = new Rook(ch, 8, "BR");
+      Rook newRook = new Rook(ch, 8, false, "BR");
       this.blackPieces.add(newRook);
     }
     //  Knight
     for(char ch = 'B'; ch < 'H'; ch += 5){
-      Knight newKnight = new Knight(ch, 8, "BN");
+      Knight newKnight = new Knight(ch, 8, false, "BN");
       this.blackPieces.add(newKnight);
     }
     //  Bishop
     for(char ch = 'C'; ch < 'G'; ch += 3){
-      Bishop newBishop = new Bishop(ch, 8, "BB");
+      Bishop newBishop = new Bishop(ch, 8, false, "BB");
       this.blackPieces.add(newBishop);
     }
     //   Queen
-    Queen blackQueen = new Queen('E', 8, "BQ");
+    Queen blackQueen = new Queen('E', 8, false, "BQ");
     this.blackPieces.add(blackQueen);
     //  King
-    King blackKing = new King('D', 8, "BK");
+    King blackKing = new King('D', 8, false, "BK");
     this.blackPieces.add(blackKing);
   }
 
@@ -138,6 +138,7 @@ public class Board{
     System.out.println("WN: White Knight\t|\tBN: Black Knight");
     System.out.println("WR: White Rook  \t|\tBR: Black Rook");
     System.out.println("WP: White Pawn  \t|\tBP: Black Pawn");
+    System.out.println("Acceptable Command: '2D 4D'(Move From 2D to 4D)");
   }
 
   public void printBoard(){
@@ -193,11 +194,18 @@ public class Board{
           if( found && !toBusy ){// Found and to is not busy
 
             for(Piece p : selector){
-              if( p.getY() == fromArray[0] - '0' && p.getX() == fromArray[1] ){
-
-                p.setY(toArray[0] - '0');
-                p.setX(toArray[1]);
-                return true;
+              if( p.getY() == fromArray[0] - '0' && p.getX() == fromArray[1] ){ // Find Piece in select
+
+                // To Do: Check if pathway is busy
+                // To Do: Check if king is checked and have to move king
+                if( p.canMove(toArray[1], toArray[0] - '0') ){ // Check if move is valid
+
+                  p.setY(toArray[0] - '0');
+                  p.setX(toArray[1]);
+                  return true;
+                }else{
+                  return false;
+                }
               }
             }
             return false;

King.java

 public class King extends Piece{
-  public King(char x, int y, String name){
-    super(x, y, name);
+  public King(char x, int y, boolean color, String name){
+    super(x, y, color, name);
+  }
+
+  public boolean canMove(char x, int y){ // Ignore the presence of other pieces
+    if( Math.abs(this.x - x) < 2 && Math.abs(this.y - y) < 2 ){
+
+      return true;
+    }
+    return false;
   }
 }

Knight.java

 public class Knight extends Piece{
-  public Knight(char x, int y, String name){
-    super(x, y, name);
+  public Knight(char x, int y, boolean color, String name){
+    super(x, y, color, name);
+  }
+
+  public boolean canMove(char x, int y){
+    int X[] = { 2, 1, -1, -2, -2, -1, 1, 2 };
+    int Y[] = { 1, 2, 2, 1, -1, -2, -2, -1 };
+    for (int i = 0; i < 8; i++) {
+        if( y == this.y + Y[i] && x == (char)(this.x + X[i]) ){
+
+          return true;
+        }
+    }
+    return false;
   }
 }

Main.java

 import java.util.*;
+import java.util.concurrent.*;
+import java.io.IOException;
 
 public class Main{
-  public static void main(String[] args){
+  public static void main(String[] args) throws IOException, InterruptedException{
     Scanner sc = new Scanner(System.in);
     Board mainBoard = new Board();
     mainBoard.initPieces();
     // mainBoard.printHelp();
-    mainBoard.move("8D", "3A", "B");
-    mainBoard.printBoard();
+    String player = "W";
+    for(int i = 0; i < 500; i++){
+      while(true){
+        new ProcessBuilder("cmd", "/c", "cls").inheritIO().start().waitFor();
+        mainBoard.printBoard();
+        if( player.equals("W") ){
+
+          System.out.print("White ");
+        }else{
+          System.out.print("Black ");
+        }
+        System.out.print("Player Move: ");
+        String input = sc.nextLine();
+        if( mainBoard.move(input.split(" ")[0], input.split(" ")[1], player) ){
+          break;
+        }
+      }
+      if( player.equals("W") ){// Change PLayer
+
+        player = "B";
+      }else{
+        player = "W";
+      }
+    }
     sc.close();
   }
 }

Pawn.java

 public class Pawn extends Piece{
   private boolean firstMove;
-  public Pawn(char x, int y, String name){
-    super(x, y, name);
+  public Pawn(char x, int y, boolean color, String name){
+    super(x, y, color, name);
     this.firstMove = true;
   }
 
@@ -12,4 +12,26 @@ public class Pawn extends Piece{
   public boolean getFirstMove(){
     return this.firstMove;
   }
+
+  public boolean canMove(char x, int y){ // Ignore the presence of other pieces
+    if( this.x - x == 0 ){
+
+      if( Math.abs(this.y - y) == 1 || (this.firstMove && Math.abs(this.y - y) == 2) ){
+
+        if( (this.color && y - this.y > 0) || (!this.color && this.y - y > 0) ){ // Moving Backward
+
+          if( this.firstMove ){
+
+            this.firstMove = false;
+          }
+          return true;
+        }else{
+          return false;
+        }
+      }else{
+        return false;
+      }
+    }
+    return false;
+  }
 }

Piece.java

 public abstract class Piece{
-  private int y;
-  private char x;
+  protected int y;
+  protected char x;
+  protected boolean color;
   private String name;
 
-  public Piece(char x, int y, String name){
+  public Piece(char x, int y, boolean color, String name){
     setX(x);
     setY(y);
+    setColor(color);
     setName(name);
   }
 
@@ -21,6 +23,10 @@ public abstract class Piece{
     this.name = name;
   }
 
+  public void setColor(boolean color){
+    this.color = color;
+  }
+
   public int getY(){
     return this.y;
   }
@@ -32,4 +38,10 @@ public abstract class Piece{
   public String getName(){
     return this.name;
   }
+
+  public boolean getColor(){
+    return this.color;
+  }
+
+  abstract boolean canMove(char x, int y);
 }

Queen.java

 public class Queen extends Piece{
-  public Queen(char x, int y, String name){
-    super(x, y, name);
+  public Queen(char x, int y, boolean color, String name){
+    super(x, y, color, name);
+  }
+
+  public boolean canMove(char x, int y){ // Ignore the presence of other pieces
+    if( Rook.canMove(this, x, y) || Bishop.canMove(this, x, y) ){
+
+      return true;
+    }
+    return false;
   }
 }

Rook.java

 public class Rook extends Piece{
-  public Rook(char x, int y, String name){
-    super(x, y, name);
+  public Rook(char x, int y, boolean color, String name){
+    super(x, y, color, name);
+  }
+
+  public boolean canMove(char x, int y){ // Ignore the presence of other pieces
+    if( this.x - x == 0 || this.y - y == 0 ){
+
+      return true;
+    }
+    return false;
+  }
+
+  public static boolean canMove(Piece p, char x, int y){ // Ignore the presence of other pieces
+    if( p.x - x == 0 || p.y - y == 0 ){
+
+      return true;
+    }
+    return false;
   }
 }