Add netty websocket game server with web client

2026-06-09 06:15:06 +00:00 · 2025-02-05 13:54:13 +00:00
parent b829ebc717
commit 5ad793e069
8 changed files with 521 additions and 2 deletions
@@ -1,2 +1,52 @@
-# test-solver
-Test Solver
+# Netty WebSocket Game Server
+
+A simple game server implementation using Netty 4 with WebSocket support.
+
+## Features
+- WebSocket-based game server using Netty 4
+- JSON message protocol for client-server communication
+- Built-in HTTP server for serving the web client
+- Simple web-based test client
+
+## Prerequisites
+- Java 11 or higher
+- Maven 3.6 or higher
+
+## Building the Project
+```bash
+mvn clean package
+```
+
+## Running the Server
+```bash
+java -cp target/netty-game-server-1.0-SNAPSHOT.jar com.gameserver.GameServer
+```
+By default, the server runs on port 8080. You can specify a different port as a command-line argument:
+```bash
+java -cp target/netty-game-server-1.0-SNAPSHOT.jar com.gameserver.GameServer 9000
+```
+
+## Testing the Server
+1. Start the server using the instructions above
+2. Open a web browser and navigate to `http://localhost:8080`
+3. Use the web interface to send test messages to the server
+
+## Message Protocol
+The server uses a simple JSON-based message protocol:
+```json
+{
+    "type": "MESSAGE_TYPE",
+    "payload": "Message content"
+}
+```
+
+### Supported Message Types
+- `PING`: Basic ping message
+- Any other type will be echoed back with a `SERVER_RESPONSE` type
+
+## Project Structure
+- `GameServer.java`: Main server class that initializes Netty
+- `GameWebSocketHandler.java`: Handles WebSocket frame processing
+- `GameMessage.java`: Message model for client-server communication
+- `HttpStaticFileHandler.java`: Serves static web content
+- `index.html`: Web-based test client
@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.gameserver</groupId>
+    <artifactId>netty-game-server</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+        <netty.version>4.1.94.Final</netty.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.netty</groupId>
+            <artifactId>netty-all</artifactId>
+            <version>${netty.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>2.0.7</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.4.8</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.15.2</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.11.0</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>
@@ -0,0 +1,33 @@
+package com.gameserver;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public class GameMessage {
+    private final String type;
+    private final String payload;
+
+    @JsonCreator
+    public GameMessage(
+            @JsonProperty("type") String type,
+            @JsonProperty("payload") String payload) {
+        this.type = type;
+        this.payload = payload;
+    }
+
+    public String getType() {
+        return type;
+    }
+
+    public String getPayload() {
+        return payload;
+    }
+
+    @Override
+    public String toString() {
+        return "GameMessage{" +
+                "type='" + type + '\'' +
+                ", payload='" + payload + '\'' +
+                '}';
+    }
+}
@@ -0,0 +1,85 @@
+package com.gameserver;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.Channel;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelPipeline;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+import io.netty.handler.codec.http.HttpObjectAggregator;
+import io.netty.handler.codec.http.HttpServerCodec;
+import io.netty.handler.codec.http.websocketx.WebSocketServerProtocolHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class GameServer {
+    private static final Logger logger = LoggerFactory.getLogger(GameServer.class);
+    private final int port;
+    private EventLoopGroup bossGroup;
+    private EventLoopGroup workerGroup;
+
+    public GameServer(int port) {
+        this.port = port;
+    }
+
+    public void start() throws Exception {
+        bossGroup = new NioEventLoopGroup(1);
+        workerGroup = new NioEventLoopGroup();
+
+        try {
+            ServerBootstrap bootstrap = new ServerBootstrap();
+            bootstrap.group(bossGroup, workerGroup)
+                    .channel(NioServerSocketChannel.class)
+                    .childHandler(new ChannelInitializer<SocketChannel>() {
+                        @Override
+                        protected void initChannel(SocketChannel ch) {
+                            ChannelPipeline pipeline = ch.pipeline();
+                            // HTTP codec for WebSocket handshake and static files
+                            pipeline.addLast(new HttpServerCodec());
+                            pipeline.addLast(new HttpObjectAggregator(65536));
+                            
+                            // Static file handler for serving the web client
+                            pipeline.addLast(new HttpStaticFileHandler("src/main/resources/static"));
+                            
+                            // WebSocket protocol handler
+                            pipeline.addLast(new WebSocketServerProtocolHandler("/game", null, true));
+                            
+                            // Game handler for WebSocket frames
+                            pipeline.addLast(new GameWebSocketHandler());
+                        }
+                    });
+
+            Channel channel = bootstrap.bind(port).sync().channel();
+            logger.info("Game server started on port {}", port);
+            channel.closeFuture().sync();
+        } finally {
+            shutdown();
+        }
+    }
+
+    public void shutdown() {
+        if (bossGroup != null) {
+            bossGroup.shutdownGracefully();
+        }
+        if (workerGroup != null) {
+            workerGroup.shutdownGracefully();
+        }
+        logger.info("Game server shutdown complete");
+    }
+
+    public static void main(String[] args) {
+        int port = 8080;
+        if (args.length > 0) {
+            port = Integer.parseInt(args[0]);
+        }
+
+        GameServer server = new GameServer(port);
+        try {
+            server.start();
+        } catch (Exception e) {
+            logger.error("Failed to start game server", e);
+        }
+    }
+}
@@ -0,0 +1,52 @@
+package com.gameserver;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.SimpleChannelInboundHandler;
+import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
+import io.netty.handler.codec.http.websocketx.WebSocketFrame;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class GameWebSocketHandler extends SimpleChannelInboundHandler<WebSocketFrame> {
+    private static final Logger logger = LoggerFactory.getLogger(GameWebSocketHandler.class);
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    protected void channelRead0(ChannelHandlerContext ctx, WebSocketFrame frame) {
+        if (frame instanceof TextWebSocketFrame) {
+            String text = ((TextWebSocketFrame) frame).text();
+            try {
+                GameMessage message = objectMapper.readValue(text, GameMessage.class);
+                logger.info("Received message: {}", message);
+                
+                // Create response message
+                GameMessage response = new GameMessage("SERVER_RESPONSE", "Received: " + message.getType());
+                String responseJson = objectMapper.writeValueAsString(response);
+                ctx.channel().writeAndFlush(new TextWebSocketFrame(responseJson));
+            } catch (Exception e) {
+                logger.error("Error processing message: {}", e.getMessage());
+                ctx.channel().writeAndFlush(new TextWebSocketFrame("Error processing message"));
+            }
+        } else {
+            String message = "Unsupported frame type: " + frame.getClass().getName();
+            throw new UnsupportedOperationException(message);
+        }
+    }
+
+    @Override
+    public void handlerAdded(ChannelHandlerContext ctx) {
+        logger.info("Client connected: {}", ctx.channel().remoteAddress());
+    }
+
+    @Override
+    public void handlerRemoved(ChannelHandlerContext ctx) {
+        logger.info("Client disconnected: {}", ctx.channel().remoteAddress());
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
+        logger.error("Channel exception: {}", cause.getMessage());
+        ctx.close();
+    }
+}
@@ -0,0 +1,143 @@
+package com.gameserver;
+
+import io.netty.channel.*;
+import io.netty.handler.codec.http.*;
+import io.netty.handler.stream.ChunkedFile;
+import io.netty.handler.ssl.SslHandler;
+
+import java.io.*;
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+
+import static io.netty.handler.codec.http.HttpHeaderNames.*;
+import static io.netty.handler.codec.http.HttpHeaderValues.KEEP_ALIVE;
+import static io.netty.handler.codec.http.HttpResponseStatus.*;
+import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
+
+public class HttpStaticFileHandler extends SimpleChannelInboundHandler<FullHttpRequest> {
+    private final String staticPath;
+
+    public HttpStaticFileHandler(String staticPath) {
+        this.staticPath = staticPath;
+    }
+
+    @Override
+    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest request) throws Exception {
+        if (!request.decoderResult().isSuccess()) {
+            sendError(ctx, BAD_REQUEST);
+            return;
+        }
+
+        if (!HttpMethod.GET.equals(request.method())) {
+            sendError(ctx, METHOD_NOT_ALLOWED);
+            return;
+        }
+
+        final String uri = request.uri();
+        final String path = sanitizeUri(uri);
+        if (path == null) {
+            sendError(ctx, FORBIDDEN);
+            return;
+        }
+
+        File file = new File(staticPath + path);
+        if (!file.exists()) {
+            sendError(ctx, NOT_FOUND);
+            return;
+        }
+
+        if (file.isDirectory()) {
+            if (uri.endsWith("/")) {
+                file = new File(file, "index.html");
+            } else {
+                sendRedirect(ctx, uri + '/');
+                return;
+            }
+        }
+
+        if (!file.isFile()) {
+            sendError(ctx, FORBIDDEN);
+            return;
+        }
+
+        try {
+            RandomAccessFile raf = new RandomAccessFile(file, "r");
+            long fileLength = raf.length();
+
+            HttpResponse response = new DefaultHttpResponse(HTTP_1_1, OK);
+            HttpUtil.setContentLength(response, fileLength);
+            setContentTypeHeader(response, file);
+
+            if (HttpUtil.isKeepAlive(request)) {
+                response.headers().set(CONNECTION, KEEP_ALIVE);
+            }
+
+            ctx.write(response);
+            ChannelFuture sendFileFuture = ctx.write(new ChunkedFile(raf, 0, fileLength, 8192),
+                    ctx.newProgressivePromise());
+            ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
+
+            if (!HttpUtil.isKeepAlive(request)) {
+                lastContentFuture.addListener(ChannelFutureListener.CLOSE);
+            }
+        } catch (FileNotFoundException fnfe) {
+            sendError(ctx, NOT_FOUND);
+        }
+    }
+
+    private static void sendError(ChannelHandlerContext ctx, HttpResponseStatus status) {
+        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, status);
+        response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");
+        response.content().writeBytes(status.toString().getBytes(StandardCharsets.UTF_8));
+
+        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
+    }
+
+    private static void sendRedirect(ChannelHandlerContext ctx, String newUri) {
+        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, FOUND);
+        response.headers().set(LOCATION, newUri);
+
+        ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
+    }
+
+    private static String sanitizeUri(String uri) {
+        try {
+            uri = URLDecoder.decode(uri, StandardCharsets.UTF_8.name());
+        } catch (UnsupportedEncodingException e) {
+            try {
+                uri = URLDecoder.decode(uri, StandardCharsets.ISO_8859_1.name());
+            } catch (UnsupportedEncodingException ex) {
+                throw new Error(ex);
+            }
+        }
+
+        if (!uri.startsWith("/")) {
+            return null;
+        }
+
+        uri = uri.replace('/', File.separatorChar);
+        if (uri.contains(File.separator + '.') ||
+            uri.contains('.' + File.separator) ||
+            uri.startsWith(".") || uri.endsWith(".") ||
+            uri.contains("..")) {
+            return null;
+        }
+
+        return uri;
+    }
+
+    private static void setContentTypeHeader(HttpResponse response, File file) {
+        String name = file.getName().toLowerCase();
+        if (name.endsWith(".html") || name.endsWith(".htm")) {
+            response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
+        } else if (name.endsWith(".css")) {
+            response.headers().set(CONTENT_TYPE, "text/css; charset=UTF-8");
+        } else if (name.endsWith(".js")) {
+            response.headers().set(CONTENT_TYPE, "application/javascript; charset=UTF-8");
+        } else if (name.endsWith(".json")) {
+            response.headers().set(CONTENT_TYPE, "application/json; charset=UTF-8");
+        } else {
+            response.headers().set(CONTENT_TYPE, "application/octet-stream");
+        }
+    }
+}
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <!-- Set logging level for our game server -->
+    <logger name="com.gameserver" level="INFO"/>
+
+    <!-- Set Netty logging to WARN to reduce noise -->
+    <logger name="io.netty" level="WARN"/>
+
+    <root level="INFO">
+        <appender-ref ref="CONSOLE"/>
+    </root>
+</configuration>
@@ -0,0 +1,84 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Game Server Test Client</title>
+    <style>
+        #messages {
+            height: 300px;
+            overflow-y: scroll;
+            border: 1px solid #ccc;
+            margin-bottom: 10px;
+            padding: 10px;
+        }
+        .sent { color: blue; }
+        .received { color: green; }
+        .error { color: red; }
+    </style>
+</head>
+<body>
+    <h2>Game Server Test Client</h2>
+    <div id="messages"></div>
+    <div>
+        <label for="messageType">Message Type:</label>
+        <input type="text" id="messageType" value="PING" />
+        <label for="messagePayload">Payload:</label>
+        <input type="text" id="messagePayload" value="Hello server!" />
+        <button onclick="sendMessage()">Send</button>
+    </div>
+
+    <script>
+        let ws;
+        const messagesDiv = document.getElementById('messages');
+
+        function connect() {
+            ws = new WebSocket('ws://localhost:8080/game');
+            
+            ws.onopen = function() {
+                appendMessage('Connected to server', 'received');
+            };
+            
+            ws.onmessage = function(event) {
+                appendMessage('Received: ' + event.data, 'received');
+            };
+            
+            ws.onclose = function() {
+                appendMessage('Disconnected from server', 'error');
+                // Try to reconnect in 5 seconds
+                setTimeout(connect, 5000);
+            };
+            
+            ws.onerror = function(error) {
+                appendMessage('Error: ' + error.message, 'error');
+            };
+        }
+
+        function sendMessage() {
+            if (!ws || ws.readyState !== WebSocket.OPEN) {
+                appendMessage('Not connected to server', 'error');
+                return;
+            }
+
+            const type = document.getElementById('messageType').value;
+            const payload = document.getElementById('messagePayload').value;
+            const message = {
+                type: type,
+                payload: payload
+            };
+
+            ws.send(JSON.stringify(message));
+            appendMessage('Sent: ' + JSON.stringify(message), 'sent');
+        }
+
+        function appendMessage(message, className) {
+            const div = document.createElement('div');
+            div.className = className;
+            div.textContent = message;
+            messagesDiv.appendChild(div);
+            messagesDiv.scrollTop = messagesDiv.scrollHeight;
+        }
+
+        // Connect when page loads
+        connect();
+    </script>
+</body>
+</html>