一、maven配置

<!-- springboot版本 -->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
    <relativePath />
</parent>

<!-- 设置编码及版本号 -->
<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <!--默认关掉单元测试 -->
    <skipTests>true</skipTests>
    <fastjson.version>1.2.31</fastjson.version>
    <netty.version>4.1.6.Final</netty.version>
</properties>

<!-- 依赖 -->
<dependencies>
    <!-- web项目必要的依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <!-- 热启动devtools -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <optional>true</optional>
        <scope>true</scope>
    </dependency>

    <!-- alibaba fastjson -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>${fastjson.version}</version>
    </dependency>

    <!-- netty -->
    <dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-all</artifactId>
        <version>${netty.version}</version>
    </dependency>
</dependencies>

<build>
    <finalName>${project.artifactId}</finalName>
    <plugins>
        <!-- 支持devtools -->
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
                <!-- 没有该配置,devtools不生效 -->
                <fork>true</fork>
            </configuration>
        </plugin>
    </plugins>
</build>

二、netty服务端编写

NettyServer

/**
 * netty服务端 . <br>
 * 
 * @author hkb
 */
@Component
public class NettyServer {

    /**
     * 日志
     */
    private Logger log = LoggerFactory.getLogger(getClass());

    /**
     * 端口号
     */
    @Value("${netty.port}")
    private int port;

    /**
     * 启动服务器方法
     * 
     * @param port
     */
    public void run() {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup, workerGroup);
            serverBootstrap.channel(NioServerSocketChannel.class);
            serverBootstrap.option(ChannelOption.SO_BACKLOG, 1024);
            serverBootstrap.handler(new LoggingHandler(LogLevel.INFO));
            serverBootstrap.childOption(ChannelOption.TCP_NODELAY, true);
            serverBootstrap.childOption(ChannelOption.SO_KEEPALIVE, true);
            serverBootstrap.childHandler(new NettyServerInitializer());
            // 绑定端口,开始接收进来的连接
            ChannelFuture channelFuture = serverBootstrap.bind(port).sync();
            log.info("netty服务启动: [port:" + port + "]");
            // 等待服务器socket关闭
            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            log.error("netty服务启动异常-" + e.getMessage());
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

}

NettyServerInitializer

/**
 * 服务端初始化 . <br>
 * 
 * @author hkb
 */
public class NettyServerInitializer extends ChannelInitializer<SocketChannel> {

    /**
     * 初始化channel
     */
    @Override
    public void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
        pipeline.addLast(new NettyServerHandler());
    }

}

NettyServerHandler

/**
 * 服务端处理器 . <br>
 * 
 * @author hkb
 */
public class NettyServerHandler extends SimpleChannelInboundHandler<String> {

    /**
     * 日志
     */
    private Logger log = LoggerFactory.getLogger(getClass());

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) {
        StringBuilder sb = null;
        Map<String, Object> result = null;
        try {
            // 报文解析处理
            sb = new StringBuilder();
            result = JSON.parseObject(msg);

            sb.append(result);
            sb.append("解析成功");
            sb.append("n");
            ctx.writeAndFlush(sb);
        } catch (Exception e) {
            String errorCode = "-1n";
            ctx.writeAndFlush(errorCode);
            log.error("报文解析失败: " + e.getMessage());
        }
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        InetSocketAddress insocket = (InetSocketAddress) ctx.channel().remoteAddress();
        String clientIp = insocket.getAddress().getHostAddress();
        log.info("收到客户端[ip:" + clientIp + "]连接");
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        // 当出现异常就关闭连接
        ctx.close();
    }

}

三、配置netty随tomcat启动

/**
 * netty服务监听器 . <br>
 * 
 * @author hkb
 */
@WebListener
public class NettyServerListener implements ServletContextListener {

    /**
     * 注入NettyServer
     */
    @Autowired
    private NettyServer nettyServer;

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        Thread thread = new Thread(new NettyServerThread());
        // 启动netty服务
        thread.start();
    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {

    }

    /**
     * netty服务启动线程 . <br>
     * 
     * @author hkb
     */
    private class NettyServerThread implements Runnable {

        @Override
        public void run() {
            nettyServer.run();
        }
    }

}

四、netty客户端测试

NettyClient

/**
 * netty客户端 . <br>
 * 
 * @author hkb
 */
public class NettyClient {

    /**
     * 主机
     */
    private String host;

    /**
     * 端口号
     */
    private int port;

    /**
     * 构造函数
     * 
     * @param host
     * @param port
     */
    public NettyClient(String host, int port) {
        this.host = host;
        this.port = port;
    }

    /**
     * 连接方法
     */
    public void connect() {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap bootstrap = new Bootstrap();
            bootstrap.group(group).channel(NioSocketChannel.class);
            bootstrap.option(ChannelOption.TCP_NODELAY, true);
            // bootstrap.option(ChannelOption.SO_KEEPALIVE, true);
            bootstrap.handler(new NettyClientInitializer());
            Channel channel = bootstrap.connect(host, port).sync().channel();
            // 发送json字符串
            String msg = "{"name":"admin","age":27}n";
            channel.writeAndFlush(msg);
            channel.closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            group.shutdownGracefully();
        }
    }

    /**
     * 测试入口
     * 
     * @param args
     */
    public static void main(String[] args) {
        String host = "127.0.0.1";
        int port = 8088;
        NettyClient nettyClient = new NettyClient(host, port);
        nettyClient.connect();
    }

}

NettyClientInitializer

/**
 * 客户端初始化 . <br>
 * 
 * @author hkb
 */
public class NettyClientInitializer extends ChannelInitializer<SocketChannel> {

    /**
     * 初始化channel
     */
    @Override
    public void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast(new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
        pipeline.addLast(new NettyClientHandler());
    }
}

NettyClientHandler

/**
 * 客户端处理器 . <br>
 * 
 * @author hkb
 */
public class NettyClientHandler extends SimpleChannelInboundHandler<String> {

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        System.out.println("收到服务端消息: " + msg);
    }
}

五、运行结果

服务端

客户端