springboot集成netty实现websocket消息推送，请给出具体代码

您好，以下是Spring Boot集成Netty实现WebSocket消息推送的示例代码：

1. 首先，在pom.xml文件中添加以下依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>4.1.25.Final</version>
</dependency>

2. 创建WebSocket处理器类：

@Component
@ChannelHandler.Sharable
public class WebSocketHandler extends SimpleChannelInboundHandler<TextWebSocketFrame> {

    private static final Logger logger = LoggerFactory.getLogger(WebSocketHandler.class);

    private WebSocketServerHandshaker handshaker;

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        logger.info("WebSocket连接已建立");
        WebSocketManager.add(ctx.channel());
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        logger.info("WebSocket连接已关闭");
        WebSocketManager.remove(ctx.channel());
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, TextWebSocketFrame msg) throws Exception {
        logger.info("收到消息：" + msg.text());
        // 处理消息
        // ...
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        logger.error("WebSocket异常", cause);
        ctx.close();
    }

    public void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
        if (!req.decoderResult().isSuccess()) {
            sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST));
            return;
        }

        WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(getWebSocketLocation(req), null, true);
        handshaker = wsFactory.newHandshaker(req);
        if (handshaker == null) {
            WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel());
        } else {
            handshaker.handshake(ctx.channel(), req);
        }
    }

    private static void sendHttpResponse(ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
        if (res.status().code() != 200) {
            ByteBuf buf = Unpooled.copiedBuffer(res.status().toString(), CharsetUtil.UTF_8);
            res.content().writeBytes(buf);
            buf.release();
            HttpUtil.setContentLength(res, res.content().readableBytes());
        }

        ChannelFuture f = ctx.channel().writeAndFlush(res);
        if (!HttpUtil.isKeepAlive(req) || res.status().code() != 200) {
            f.addListener(ChannelFutureListener.CLOSE);
        }
    }

    private static String getWebSocketLocation(FullHttpRequest req) {
        String location = req.headers().get(HttpHeaderNames.HOST) + "/websocket";
        return "ws://" + location;
    }
}

3. 创建WebSocket管理器类：

@Component
public class WebSocketManager {

    private static final Logger logger = LoggerFactory.getLogger(WebSocketManager.class);

    private static final List<Channel> channels = new CopyOnWriteArrayList<>();

    public static void add(Channel channel) {
        channels.add(channel);
    }

    public static void remove(Channel channel) {
        channels.remove(channel);
    }

    public static void broadcast(String message) {
        logger.info("广播消息：" + message);
        TextWebSocketFrame frame = new TextWebSocketFrame(message);
        for (Channel channel : channels) {
            if (channel.isActive()) {
                channel.writeAndFlush(frame);
            }
        }
    }
}

4. 创建WebSocket配置类：

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {

    @Autowired
    private WebSocketHandler webSocketHandler;

    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(webSocketHandler, "/websocket").setAllowedOrigins("*");
    }
}

5. 在需要推送消息的地方调用WebSocketManager的broadcast方法即可：

WebSocketManager.broadcast("Hello, WebSocket!");

希望这个示例能够帮助到您。