Netty之网络编程阻塞篇

阻塞模式下，相关方法都会导致线程暂停

ServerSocketChannel.accept 会在没有连接建立时让线程暂停SocketChannel.read 会在通道中没有数据可读时让线程暂停阻塞的表现其实就是线程暂停了，暂停期间不会占用 cpu，但线程相当于闲置。 2.通过设置serverSocketChannel.configureBlocking(false)设置成非阻塞模式

package netty.io;

import lombok.extern.slf4j.Slf4j;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.ByteBuffer;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.ArrayList;
import java.util.List;
@Slf4j
public class ZuSeServer {
    public static void main(String[] args) throws IOException {
        //0Bytebuffer
        ByteBuffer byteBuffer=ByteBuffer.allocate(16);
        //1创建了服务器
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(false);//设置成非阻塞模式
        //2绑定端口
        serverSocketChannel.bind(new InetSocketAddress(8080));
        //3连接的集合 存放channel
        List channels=new ArrayList<>();
        while(true){
            //4 accept建立于客户端连接
            log.info("connetcing...");
//            System.out.println("connecting...");
            SocketChannel sc = serverSocketChannel.accept();//也是阻塞
            sc.configureBlocking(false);
            log.info("connected...");
            channels.add(sc);
            for(SocketChannel channel:channels){
                //5接受客户端发送的数据
                log.info("before read",channel);
                channel.read(byteBuffer);//也是阻塞
                byteBuffer.flip();
//                ByteBufferUtil.debugAll(byteBuffer);
                byteBuffer.clear();
                log.info("after read");
            }
        }

    }
}