## 綁定端口并啟動 ``` public void start() { try { // 綁定端口，同步等待成功 ChannelFuture future = server.bind(new InetSocketAddress(8888)).sync(); // 等待服務監聽端口關閉 future.channel().closeFuture().sync(); } catch (InterruptedException e) { e.printStackTrace(); } finally { // 優雅退出，釋放線程池資源 mainGroup.shutdownGracefully(); subGroup.shutdownGracefully(); } } ``` ### 遇到過的問題 使用`new InetSocketAddress(8888)`無法啟動： 原因：多網卡； ``` public void start() { this.future = server.bind("192.168.30.51",8888); if (future.isSuccess()) { log.info("啟動 Netty 成功"); } } ``` ## Netty線程組啟動時，默認線程為多少？ ``` public abstract class MultithreadEventLoopGroup extends MultithreadEventExecutorGroup implements EventLoopGroup { private static final InternalLogger logger = InternalLoggerFactory.getInstance(MultithreadEventLoopGroup.class); private static final int DEFAULT_EVENT_LOOP_THREADS; static { DEFAULT_EVENT_LOOP_THREADS = Math.max(1, SystemPropertyUtil.getInt( "io.netty.eventLoopThreads", NettyRuntime.availableProcessors() * 2)); if (logger.isDebugEnabled()) { logger.debug("-Dio.netty.eventLoopThreads: {}", DEFAULT_EVENT_LOOP_THREADS); } } ... } ``` 默認取-Dio.netty.eventLoopThreads，如果該系統參數也沒有指定，則為可用的CPU內核數 × 2。 ## 其他資料 1. [netty源碼淺析--線程啟動](https://blog.csdn.net/c275046758/article/details/52262167)