From b8053f1e84cc74f3ea5f7aaf4a7024e1dfa174e5 Mon Sep 17 00:00:00 2001
From: Kirill Buslovskii <k.buslovsky@yandex.ru>
Date: Mon, 12 Jan 2026 23:21:08 +0300
Subject: [PATCH 1/2] create InitServlet and LogicServlet, read some logic.
 some feature in index.jsp and pom

---
 pom.xml                                       | 22 +++++----
 src/main/java/com/tictactoe/InitServlet.java  | 30 ++++++++++++
 src/main/java/com/tictactoe/LogicServlet.java | 47 +++++++++++++++++++
 src/main/webapp/index.jsp                     | 21 ++++++++-
 src/main/webapp/static/main.css               | 11 +++++
 5 files changed, 122 insertions(+), 9 deletions(-)
 create mode 100644 src/main/java/com/tictactoe/InitServlet.java
 create mode 100644 src/main/java/com/tictactoe/LogicServlet.java

diff --git a/pom.xml b/pom.xml
index cb226e88..6bedcc42 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,21 +12,27 @@
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.target>18</maven.compiler.target>
-        <maven.compiler.source>18</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <maven.compiler.source>21</maven.compiler.source>
     </properties>
 
+
     <dependencies>
         <dependency>
-            <groupId>javax.servlet</groupId>
-            <artifactId>javax.servlet-api</artifactId>
-            <version>4.0.1</version>
+            <groupId>jakarta.servlet</groupId>
+            <artifactId>jakarta.servlet-api</artifactId>
+            <version>6.0.0</version>
             <scope>provided</scope>
         </dependency>
         <dependency>
-            <groupId>javax.servlet</groupId>
-            <artifactId>jstl</artifactId>
-            <version>1.2</version>
+            <groupId>jakarta.servlet.jsp.jstl</groupId>
+            <artifactId>jakarta.servlet.jsp.jstl-api</artifactId>
+            <version>3.0.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.glassfish.web</groupId>
+            <artifactId>jakarta.servlet.jsp.jstl</artifactId>
+            <version>3.0.1</version>
         </dependency>
     </dependencies>
 
diff --git a/src/main/java/com/tictactoe/InitServlet.java b/src/main/java/com/tictactoe/InitServlet.java
new file mode 100644
index 00000000..9e44c1e4
--- /dev/null
+++ b/src/main/java/com/tictactoe/InitServlet.java
@@ -0,0 +1,30 @@
+package com.tictactoe;
+
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebServlet;
+import jakarta.servlet.http.HttpServlet;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import jakarta.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 currentSession = req.getSession(true);
+
+        Field field = new Field();
+        Map<Integer, Sign> fieldData = field.getField();
+
+        List<Sign> data = field.getFieldData();
+
+        currentSession.setAttribute("field", field);
+        currentSession.setAttribute("data", data);
+
+        getServletContext().getRequestDispatcher("/index.jsp").forward(req, resp);
+    }
+}
diff --git a/src/main/java/com/tictactoe/LogicServlet.java b/src/main/java/com/tictactoe/LogicServlet.java
new file mode 100644
index 00000000..979bbaed
--- /dev/null
+++ b/src/main/java/com/tictactoe/LogicServlet.java
@@ -0,0 +1,47 @@
+package com.tictactoe;
+
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebServlet;
+import jakarta.servlet.http.HttpServlet;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import jakarta.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 currentSession = req.getSession();
+
+        Field field = extractField(currentSession);
+
+        int index = getSelectedIndex(req);
+
+        field.getField().put(index, Sign.CROSS);
+
+        List<Sign> data = field.getFieldData();
+
+        currentSession.setAttribute("data", data);
+        currentSession.setAttribute("field", field);
+
+        resp.sendRedirect("/index.jsp");
+    }
+
+    private Field extractField(HttpSession currentSession) {
+        Object fieldAttribute = currentSession.getAttribute("field");
+        if (Field.class != fieldAttribute.getClass()) {
+            currentSession.invalidate();
+            throw new RuntimeException("Session is broken, try one more time");
+        }
+        return (Field) fieldAttribute;
+    }
+
+    private int getSelectedIndex(HttpServletRequest request) {
+        String click = request.getParameter("click");
+        boolean isNumeric = click.chars().allMatch(Character::isDigit);
+        return isNumeric ? Integer.parseInt(click) : 0;
+    }
+}
diff --git a/src/main/webapp/index.jsp b/src/main/webapp/index.jsp
index 964cc071..89371816 100644
--- a/src/main/webapp/index.jsp
+++ b/src/main/webapp/index.jsp
@@ -4,10 +4,29 @@
 <html>
 <head>
     <title>Tic-Tac-Toe</title>
+    <meta charset="UTF-8">
+    <link href="static/main.css" rel="stylesheet">
+    <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 </head>
 <body>
 <h1>Tic-Tac-Toe</h1>
-
+<table>
+    <tr>
+        <td onclick="window.location='/logic?click=0'">${data.get(0).getSign()}</td>
+        <td onclick="window.location='/logic?click=1'">${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>
 
 <script>
 
diff --git a/src/main/webapp/static/main.css b/src/main/webapp/static/main.css
index e69de29b..33049a9b 100644
--- a/src/main/webapp/static/main.css
+++ b/src/main/webapp/static/main.css
@@ -0,0 +1,11 @@
+td {
+    border: 3px solid black;
+    padding: 10px;
+    border-collapse: separate;
+    margin: 10px;
+    width: 100px;
+    height: 100px;
+    font-size: 50px;
+    text-align: center;
+    empty-cells: show;
+}
\ No newline at end of file

From d26d3dbec818c4a844632f3ca4fe6b03e2bd047d Mon Sep 17 00:00:00 2001
From: Kirill Buslovskii <k.buslovsky@yandex.ru>
Date: Tue, 13 Jan 2026 23:23:44 +0300
Subject: [PATCH 2/2] all done

---
 src/main/java/com/tictactoe/LogicServlet.java | 55 +++++++++++++++++--
 .../java/com/tictactoe/RestartServlet.java    | 18 ++++++
 src/main/webapp/index.jsp                     | 31 ++++++++++-
 3 files changed, 98 insertions(+), 6 deletions(-)
 create mode 100644 src/main/java/com/tictactoe/RestartServlet.java

diff --git a/src/main/java/com/tictactoe/LogicServlet.java b/src/main/java/com/tictactoe/LogicServlet.java
index 979bbaed..61feb3b5 100644
--- a/src/main/java/com/tictactoe/LogicServlet.java
+++ b/src/main/java/com/tictactoe/LogicServlet.java
@@ -1,5 +1,6 @@
 package com.tictactoe;
 
+import jakarta.servlet.RequestDispatcher;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.annotation.WebServlet;
 import jakarta.servlet.http.HttpServlet;
@@ -19,9 +20,37 @@ protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws Se
         Field field = extractField(currentSession);
 
         int index = getSelectedIndex(req);
+        Sign currentSign = field.getField().get(index);
+
+        if (Sign.EMPTY != currentSign) {
+            RequestDispatcher requestDispatcher = getServletContext().getRequestDispatcher("/index.jsp");
+            requestDispatcher.forward(req, resp);
+            return;
+        }
 
         field.getField().put(index, Sign.CROSS);
 
+        int emptyFieldIndex = field.getEmptyFieldIndex();
+
+        if (checkWin(resp, currentSession, field)) {
+            return;
+        }
+
+        if (emptyFieldIndex >= 0) {
+            field.getField().put(emptyFieldIndex, Sign.NOUGHT);
+            if (checkWin(resp, currentSession, field)) {
+                return;
+            }
+        } else {
+            currentSession.setAttribute("draw", true);
+
+            List<Sign> data = field.getFieldData();
+            currentSession.setAttribute("data", data);
+
+            resp.sendRedirect("/index.jsp");
+            return;
+        }
+
         List<Sign> data = field.getFieldData();
 
         currentSession.setAttribute("data", data);
@@ -30,6 +59,26 @@ protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws Se
         resp.sendRedirect("/index.jsp");
     }
 
+    private boolean checkWin(HttpServletResponse response, HttpSession currentSession, Field field) throws IOException {
+        Sign winner = field.checkWin();
+        if (Sign.CROSS == winner || Sign.NOUGHT == winner) {
+            currentSession.setAttribute("winner", winner);
+
+            List<Sign> data = field.getFieldData();
+            currentSession.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 currentSession) {
         Object fieldAttribute = currentSession.getAttribute("field");
         if (Field.class != fieldAttribute.getClass()) {
@@ -39,9 +88,5 @@ private Field extractField(HttpSession currentSession) {
         return (Field) fieldAttribute;
     }
 
-    private int getSelectedIndex(HttpServletRequest request) {
-        String click = request.getParameter("click");
-        boolean isNumeric = click.chars().allMatch(Character::isDigit);
-        return isNumeric ? Integer.parseInt(click) : 0;
-    }
+
 }
diff --git a/src/main/java/com/tictactoe/RestartServlet.java b/src/main/java/com/tictactoe/RestartServlet.java
new file mode 100644
index 00000000..4ca284ab
--- /dev/null
+++ b/src/main/java/com/tictactoe/RestartServlet.java
@@ -0,0 +1,18 @@
+package com.tictactoe;
+
+import jakarta.servlet.ServletException;
+import jakarta.servlet.annotation.WebServlet;
+import jakarta.servlet.http.HttpServlet;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.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");
+    }
+}
diff --git a/src/main/webapp/index.jsp b/src/main/webapp/index.jsp
index 89371816..e1dae259 100644
--- a/src/main/webapp/index.jsp
+++ b/src/main/webapp/index.jsp
@@ -1,3 +1,4 @@
+<%@ page import="com.tictactoe.Sign" %>
 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
 
 <!DOCTYPE html>
@@ -7,6 +8,7 @@
     <meta charset="UTF-8">
     <link href="static/main.css" rel="stylesheet">
     <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
+    <script src="<c:url value="/static/jquery-3.6.0.min.js"/>"></script>
 </head>
 <body>
 <h1>Tic-Tac-Toe</h1>
@@ -27,9 +29,36 @@
         <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="${winner == CROSSES}">
+    <h1>CROSSES WIN!</h1>
+    <button onclick="restart()">Start again</button>
+</c:if>
+<c:if test="${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>