【闪电侠学netty】第5章客户端启动流程

阿里云国内75折回扣微信号：monov8

阿里云国际，腾讯云国际，低至75折。AWS 93折免费开户实名账号代冲值优惠多多微信号：monov8 飞机：@monov6

1. 内容概要

1　客户端启动Demo

启动客户端步骤

Step1线程模型服务器引导类Bootstrap
Step2IO 模型
Step3IO 处理逻辑
Step4建立连接

public class NettyClient {
    private static final int MAX_RETRY = 5;//最大重连次数


    public static void main(String[] args) {
        NioEventLoopGroup workerGroup = new NioEventLoopGroup();

        Bootstrap bootstrap = new Bootstrap();
        bootstrap
                // 1.指定线程模型
                .group(workerGroup)
                // 2.指定 IO 类型为 NIO
                .channel(NioSocketChannel.class)
                // 绑定自定义属性到 channel
                .attr(AttributeKey.newInstance("clientName"), "nettyClient")
                // 设置TCP底层属性
                .option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000)
                .option(ChannelOption.SO_KEEPALIVE, true)
                .option(ChannelOption.TCP_NODELAY, true)
                // 3.IO 处理逻辑
                .handler(new ChannelInitializer<SocketChannel>() {
                    @Override
                    public void initChannel(SocketChannel ch) {
                    }
                });

        // 4.建立连接
        connect(bootstrap, "juejin.im", 80, MAX_RETRY);
    }

    private static void connect(Bootstrap bootstrap, String host, int port, int retry) {
        bootstrap.connect(host, port).addListener(future -> {
            if (future.isSuccess()) {
                System.out.println("连接成功!");
            } else if (retry == 0) {
                System.err.println("重试次数已用完放弃连接");
            } else {
                // 第几次重连
                int order = (MAX_RETRY - retry) + 1;
                // 本次重连的间隔
                int delay = 1 << order;
                System.err.println(new Date() + ": 连接失败第" + order + "次重连……");
                bootstrap.config().group().schedule(() -> connect(bootstrap, host, port, retry - 1), delay, TimeUnit
                        .SECONDS);
            }
        });
    }
}