adding main logic

src/main/java/com/tictactoe/Field.java

@@ -31,7 +31,6 @@ public int getEmptyFieldIndex() {
                 .map(Map.Entry::getKey)
                 .findFirst().orElse(-1);
     }
-
     public List<Sign> getFieldData() {
         return field.entrySet().stream()
                 .sorted(Map.Entry.comparingByKey())

src/main/java/com/tictactoe/InitServlet.java

@@ -0,0 +1,29 @@
+package com.tictactoe;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+@WebServlet(name="InitServlet", value = "/start")
+public class InitServlet extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        HttpSession session = req.getSession(true);
+
+        Field field = new Field();
+        Map<Integer, Sign> fieldData = field.getField();
+        List<Sign> data = field.getFieldData();
+
+        session.setAttribute("field", field);
+        session.setAttribute("data", data);
+        session.setAttribute("queue", Sign.CROSS);
+
+        getServletContext().getRequestDispatcher("/index.jsp").forward(req, resp);
+    }
+}

src/main/java/com/tictactoe/LogicServlet.java

@@ -0,0 +1,92 @@
+package com.tictactoe;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+import java.io.IOException;
+import java.util.List;
+
+@WebServlet(name = "LogicServlet", value = "/logic")
+public class LogicServlet extends HttpServlet {
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        HttpSession session = req.getSession();
+        Field field = extractField(session);
+
+        int index = getSelectedIndex(req);
+        if(checkWin(resp, session, field)){
+            return;
+        }
+        Sign currentSign = field.getField().get(index);
+
+        if(Sign.EMPTY != currentSign) {
+            RequestDispatcher dispatcher = req.getServletContext().getRequestDispatcher("/index.jsp");
+            dispatcher.forward(req, resp);
+            return;
+        }
+        if(session.getAttribute("queue")  == Sign.CROSS) {
+            field.getField().put(index, Sign.CROSS);
+            if(checkWin(resp, session, field)){
+                return;
+            }
+            else {
+                session.setAttribute("queue", Sign.NOUGHT);
+            }
+        }
+        else {
+            field.getField().put(index, Sign.NOUGHT);
+            if(checkWin(resp, session, field)){
+                return;
+            }
+            else {
+                session.setAttribute("queue", Sign.CROSS);
+            }
+        }
+        if(field.getEmptyFieldIndex() == -1){
+            session.setAttribute("draw", true);
+            List<Sign> data = field.getFieldData();
+
+            session.setAttribute("data", data);
+            resp.sendRedirect("/index.jsp");
+            return;
+        }
+        List<Sign> data = field.getFieldData();
+
+        session.setAttribute("data", data);
+        session.setAttribute("field", field);
+
+        resp.sendRedirect("/index.jsp");
+    }
+    private boolean checkWin(HttpServletResponse response, HttpSession session, Field field) throws IOException {
+        Sign winner = field.checkWin();
+        if(Sign.CROSS == winner || Sign.NOUGHT == winner) {
+            session.setAttribute("winner", winner);
+
+            List<Sign> data = field.getFieldData();
+
+            session.setAttribute("data", data);
+            response.sendRedirect("/index.jsp");
+            return true;
+        }
+        return false;
+    }
+
+    private int getSelectedIndex(HttpServletRequest request) {
+        String click = request.getParameter("click");
+        boolean isNumeric = click.chars().allMatch(Character::isDigit);
+        return isNumeric ? Integer.parseInt(click) : 0;
+    }
+
+    private Field extractField(HttpSession session) {
+        Object fieldAttribute = session.getAttribute("field");
+        if(Field.class != fieldAttribute.getClass()) {
+            session.invalidate();
+            throw new RuntimeException("Session is broken, try one more time");
+        }
+        return (Field) fieldAttribute;
+    }
+}

src/main/java/com/tictactoe/RestartServlet.java

@@ -0,0 +1,17 @@
+package com.tictactoe;
+
+import javax.servlet.ServletException;
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+@WebServlet(name = "RestartServlet", value = "/restart")
+public class RestartServlet extends HttpServlet {
+    @Override
+    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
+        req.getSession().invalidate();
+        resp.sendRedirect("/start");
+    }
+}

src/main/webapp/index.jsp

@@ -1,16 +1,73 @@
+<%@ page import="com.tictactoe.Sign" %>
 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
 
 <!DOCTYPE html>
 <html>
 <head>
+    <link href="static/main.css" rel="stylesheet">
+    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
     <title>Tic-Tac-Toe</title>
+    <script src="<c:url value="/static/jquery-3.6.0.min.js"/>"></script>
 </head>
-<body>
+<body class="<c:choose>
+                <c:when test='${queue == Sign.CROSS}'>cross-turn</c:when>
+                <c:when test='${queue == Sign.NOUGHT}'>nought-turn</c:when>
+            </c:choose>">
 <h1>Tic-Tac-Toe</h1>
+<table>
+    <tr>
+        <td onclick="window.location='/logic?click=motherfucker'">${data.get(0).getSign()}</td>
+        <td onclick="window.location='/logic?click=1'">${data.get(1).getSign()}</td>
+        <td onclick="window.location='/logic?click=2'">${data.get(2).getSign()}</td>
+    </tr>
+    <tr>
+        <td onclick="window.location='/logic?click=3'">${data.get(3).getSign()}</td>
+        <td onclick="window.location='/logic?click=4'">${data.get(4).getSign()}</td>
+        <td onclick="window.location='/logic?click=5'">${data.get(5).getSign()}</td>
+    </tr>
+    <tr>
+        <td onclick="window.location='/logic?click=6'">${data.get(6).getSign()}</td>
+        <td onclick="window.location='/logic?click=7'">${data.get(7).getSign()}</td>
+        <td onclick="window.location='/logic?click=8'">${data.get(8).getSign()}</td>
+    </tr>
+</table>
 
+<hr>
+<c:set var="CROSSES" value="<%=Sign.CROSS%>"/>
+<c:set var="NOUGHTS" value="<%=Sign.NOUGHT%>"/>
 
-<script>
+<c:if test="${queue == CROSSES}">
+    <h1>Ход Х</h1>
+</c:if>
 
+<c:if test="${queue == NOUGHTS}">
+    <h1>Ход О</h1>
+</c:if>
+<c:if test="${winner == CROSSES}">
+    <h1>CROSSES WIN!</h1>
+    <button onclick="restart()">Start again</button>
+</c:if>
+<c:if test="${winner == NOUGHTS}">
+    <h1>NOUGHTS WIN!</h1>
+    <button onclick="restart()">Start again</button>
+</c:if>
+<c:if test="${draw}">
+    <h1>IT'S A DRAW</h1>
+    <br>
+    <button onclick="restart()">Start again</button>
+</c:if>
+<script>
+    function restart() {
+        $.ajax({
+            url: '/restart',
+            type: 'POST',
+            contentType: 'application/json;charset=UTF-8',
+            async: false,
+            success: function () {
+                location.reload();
+            }
+        });
+    }
 </script>
 
 </body>

src/main/webapp/static/main.css

@@ -0,0 +1,68 @@
+body {
+    font-family: Arial, sans-serif;
+    text-align: center;
+    background-color: #f0f0f0;
+    margin: 0;
+    padding: 20px;
+}
+h1 {
+    color: #333;
+}
+
+table {
+    margin: 20px auto;
+    border-collapse: collapse;
+}
+
+td {
+    width: 100px;
+    height: 100px;
+    border: 2px solid #333;
+    font-size: 2em;
+    font-weight: bold;
+    text-align: center;
+    vertical-align: middle;
+    cursor: pointer;
+    transition: background-color 0.3s ease;
+}
+
+td:hover {
+    background-color: #e0e0e0;
+}
+
+button {
+    background-color: #4CAF50;
+    color: white;
+    padding: 10px 20px;
+    margin-top: 20px;
+    border: none;
+    border-radius: 5px;
+    font-size: 1em;
+    cursor: pointer;
+    transition: background-color 0.3s ease;
+}
+
+button:hover {
+    background-color: #45a049;
+}
+
+hr {
+    margin: 20px 0;
+    border: none;
+    border-top: 2px solid #333;
+}
+
+h1:first-of-type {
+    margin-top: 0;
+}
+
+h1:last-of-type {
+    margin-bottom: 20px;
+}
+body.cross-turn {
+    background-color: #f0f8ff; /* Цвет фона для хода крестиков */
+}
+
+body.nought-turn {
+    background-color: #fffaf0; /* Цвет фона для хода ноликов */
+}