netty之Netty与SpringBoot整合

前言

在实际的开发中，我们需要对netty服务进行更多的操作，包括；获取它的状态信息、启动/停止、对客户端用户强制下线等等，为此我们需要把netty服务加入到web系统中。

MyChannelInitializer

java 复制代码

public class MyChannelInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel channel) {
        // 基于换行符号
        channel.pipeline().addLast(new LineBasedFrameDecoder(1024));
        // 解码转String，注意调整自己的编码格式GBK、UTF-8
        channel.pipeline().addLast(new StringDecoder(Charset.forName("GBK")));
        // 解码转String，注意调整自己的编码格式GBK、UTF-8
        channel.pipeline().addLast(new StringEncoder(Charset.forName("GBK")));
        // 在管道中添加我们自己的接收数据实现方法
        channel.pipeline().addLast(new MyServerHandler());
    }

}

MyServerHandler

java 复制代码

public class MyServerHandler extends ChannelInboundHandlerAdapter {

    private Logger logger = LoggerFactory.getLogger(MyServerHandler.class);

    /**
     * 当客户端主动链接服务端的链接后，这个通道就是活跃的了。也就是客户端与服务端建立了通信通道并且可以传输数据
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        SocketChannel channel = (SocketChannel) ctx.channel();
        logger.info("链接报告开始");
        logger.info("链接报告信息：有一客户端链接到本服务端");
        logger.info("链接报告IP:{}", channel.localAddress().getHostString());
        logger.info("链接报告Port:{}", channel.localAddress().getPort());
        logger.info("链接报告完毕");
        //通知客户端链接建立成功
        String str = "通知客户端链接建立成功" + " " + new Date() + " " + channel.localAddress().getHostString() + "\r\n";
        ctx.writeAndFlush(str);
    }

    /**
     * 当客户端主动断开服务端的链接后，这个通道就是不活跃的。也就是说客户端与服务端的关闭了通信通道并且不可以传输数据
     */
    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        logger.info("客户端断开链接{}", ctx.channel().localAddress().toString());
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        //接收msg消息{与上一章节相比，此处已经不需要自己进行解码}
        logger.info(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + " 服务端接收到消息：" + msg);
        //通知客户端链消息发送成功
        String str = "服务端收到：" + new Date() + " " + msg + "\r\n";
        ctx.writeAndFlush(str);
    }

    /**
     * 抓住异常，当发生异常的时候，可以做一些相应的处理，比如打印日志、关闭链接
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
        logger.info("异常信息：\r\n" + cause.getMessage());
    }

}

java 复制代码

@Component("nettyServer")
public class NettyServer {

    private Logger logger = LoggerFactory.getLogger(NettyServer.class);

    //配置服务端NIO线程组
    private final EventLoopGroup parentGroup = new NioEventLoopGroup(); //NioEventLoopGroup extends MultithreadEventLoopGroup Math.max(1, SystemPropertyUtil.getInt("io.netty.eventLoopThreads", NettyRuntime.availableProcessors() * 2));
    private final EventLoopGroup childGroup = new NioEventLoopGroup();
    private Channel channel;

    public ChannelFuture bing(InetSocketAddress address) {
        ChannelFuture channelFuture = null;
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(parentGroup, childGroup)
                    .channel(NioServerSocketChannel.class)    //非阻塞模式
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childHandler(new MyChannelInitializer());

            channelFuture = b.bind(address).syncUninterruptibly();
            channel = channelFuture.channel();
        } catch (Exception e) {
            logger.error(e.getMessage());
        } finally {
            if (null != channelFuture && channelFuture.isSuccess()) {
                logger.info("server start done. {关注明哥 获取源码}");
            } else {
                logger.error("server start error. {关注明哥 获取源码}");
            }
        }
        return channelFuture;
    }

    public void destroy() {
        if (null == channel) return;
        channel.close();
        parentGroup.shutdownGracefully();
        childGroup.shutdownGracefully();
    }

    public Channel getChannel() {
        return channel;
    }

}

java 复制代码

@SpringBootApplication
@ComponentScan("com.lm")
public class NettyApplication implements CommandLineRunner {

    @Value("${netty.host}")
    private String host;
    @Value("${netty.port}")
    private int port;
    @Autowired
    private NettyServer nettyServer;

    public static void main(String[] args) {
        SpringApplication.run(NettyApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        InetSocketAddress address = new InetSocketAddress(host, port);
        ChannelFuture channelFuture = nettyServer.bing(address);
        Runtime.getRuntime().addShutdownHook(new Thread(() -> nettyServer.destroy()));
        channelFuture.channel().closeFuture().syncUninterruptibly();
    }

}

java 复制代码

@RestController
@RequestMapping(value = "/nettyserver", method = RequestMethod.GET)
public class NettyController {

    @Resource
    private NettyServer nettyServer;

    @RequestMapping("/localAddress")
    public String localAddress() {
        return "nettyServer localAddress " + nettyServer.getChannel().localAddress();
    }

    @RequestMapping("/isOpen")
    public String isOpen() {
        return "nettyServer isOpen " + nettyServer.getChannel().isOpen();
    }

}

测试结果

启动SpringBoot *NettyApplication.main >run

启动ApiTest

Web访问 *http://localhost:8080/nettyserver/localAddress

Web访问 *http://localhost:8080/nettyserver/isOpen

好了到这里就结束了netty之Netty与SpringBoot整合的学习，大家一定要跟着动手操作起来。需要的源码的可si我获取；