netty学习

 监听器学习参考：https://blog.51cto.com/u_15116285/5964656

参考学习地址：https://www.bilibili.com/video/BV1bM411M7Dd?p=23&spm_id_from=pageDriver&vd_source=f97080956039c326589b5b26607d960b

参考学习：https://blog.csdn.net/crazymakercircle/article/details/124588880

例子：

import com.zygh.tscmp.handle.NettyClientHandler;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.timeout.IdleStateHandler;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.util.concurrent.TimeUnit;

/**
 * 系统建立连接
 */
@Component
@Slf4j
public class NettyConnectUtils {
    /**
     * 解决静态属性注入null问题
     */
    @Value("${netty.port}")
    private int sourcePort;
    @Value("${netty.url}")
    private String sourceUrl;
    private static Integer port;
    private static String url;


    @PostConstruct
    public void init() {
        url = sourceUrl;
        port = sourcePort;
    }

    /**
     * 创建连接
     */
    public static void doConnect() {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY, true)
                    .option(ChannelOption.RCVBUF_ALLOCATOR, new AdaptiveRecvByteBufAllocator(1024, 16 * 1024, 1024 * 1024))
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        public void initChannel(SocketChannel ch) throws Exception {
                            ChannelPipeline p = ch.pipeline();

                            //设置心跳检测30秒时间
                            p.addLast(new IdleStateHandler(30, 30, 0, TimeUnit.SECONDS));
                            p.addLast("decoder", new StringDecoder());
                            p.addLast("encoder", new StringEncoder());
                            p.addLast(new NettyClientHandler());
                        }
                    });

            ChannelFuture future = b.connect(url, port)
                    //增加重连监听器
                    .addListener((ChannelFuture futureListener) -> {
                        final EventLoop eventLoop = futureListener.channel().eventLoop();
                        if (!futureListener.isSuccess()) {
                            log.info("与服务端断开连接!在10s之后准备尝试重连!");
                            eventLoop.schedule(() -> doConnect(), 10, TimeUnit.SECONDS);
                        }
                    })
                    .sync();
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } finally {
            log.error("连接失败");
            group.shutdownGracefully();
        }
    }

}