Basics of client server communication and drawing of gamestates finished

Server/src/game/TicTacToe_Server.java

@@ -0,0 +1,41 @@
+package game;
+
+import java.nio.charset.StandardCharsets;
+
+public class TicTacToe_Server {
+
+    private String gameState;
+
+    public TicTacToe_Server(){
+        gameState = "---------";
+    }
+
+    public void setGameState(String gameState) {
+        this.gameState = gameState;
+    }
+
+    public String getGameState() {
+        return gameState;
+    }
+
+    public int makeClientMove(String input) {
+        int column = Double.valueOf(input.split("\\|")[0]).intValue() / 300;
+        int row = Double.valueOf(input.split("\\|")[1]).intValue() / 300;
+        int index = column * 3 + row;
+
+        if (isLegalMove(column, row)) {
+            byte[] gameStateBytes = gameState.getBytes();
+            gameStateBytes[index] = (byte) 'x';
+            gameState = new String(gameStateBytes, StandardCharsets.UTF_8);
+            return 200;
+        } else {
+            return 404;
+        }
+    }
+
+    private boolean isLegalMove(int column, int row){
+        int index = column * 3 + row;
+        return gameState.charAt(index) == '-';
+    }
+
+}