客户端发送消息 
服务端接收客户端消息并打印 ，不响应 

服务端 
AioServer.java
AcceptHandler.java
ReadHandler.java
客户端 
AioClient2.java



AioServer.java

import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousServerSocketChannel;
public class AioServer {
    static final int PORT = 8050;
    public static void main(String[] args) throws Exception {
        System.out.println(Thread.currentThread().getName() + " AioServer start,port="+PORT);
        AsynchronousServerSocketChannel serverChannel = AsynchronousServerSocketChannel.open();
        serverChannel.bind(new InetSocketAddress(PORT));
        serverChannel.accept(null, new AcceptHandler());
        Thread.sleep(Integer.MAX_VALUE);
    }
}


AcceptHandler.java

import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;

public class AcceptHandler implements CompletionHandler< AsynchronousSocketChannel, Void> {

    @Override
    public void completed(java.nio.channels.AsynchronousSocketChannel clientChannel, java.lang.Void attachment) {
        System.out.println(Thread.currentThread().getName() + " client is connected");
        // 预分配缓冲区 用于读取
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        clientChannel.read(buffer, buffer, new ReadHandler(clientChannel));
    }

    @Override
    public void failed(Throwable exc, java.lang.Void attachment) {
        System.out.println("accept fail");
    }
}



ReadHandler.java


import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.nio.charset.StandardCharsets;

public class ReadHandler implements CompletionHandler< Integer, ByteBuffer> {

    final AsynchronousSocketChannel clientChannel;

    public ReadHandler(final AsynchronousSocketChannel clientChannel){
        this.clientChannel = clientChannel;
    }

    @Override
    public void completed(Integer result, ByteBuffer buffer) {
        // flip 翻转  ，写模式转为读取模式
        buffer.flip();
        byte[] data = new byte[buffer.remaining()];
        buffer.get(data);
        System.out.println(Thread.currentThread().getName() + " received:" + new String(data, StandardCharsets.UTF_8));
        // 继续新的读取
        ByteBuffer bufferNew = ByteBuffer.allocate(1024);
        clientChannel.read(bufferNew,bufferNew,this);
    }

    @Override
    public void failed(Throwable exc, ByteBuffer buffer) {
        System.out.println("ReadHandler.failed,"+exc);
    }
}


AioClient2.java 


import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.charset.StandardCharsets;
import java.time.LocalDateTime;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;

public class AioClient2 {

    static final String HOST = "127.0.0.1";
    static final int PORT = 8050;

    static final int MAX = 1000000;
    static final AtomicInteger NO = new AtomicInteger(0);

    public static void main(String[] args) throws Exception {
        System.out.println("AioClient start,server host="+HOST+",port="+PORT);
        AsynchronousSocketChannel channel = AsynchronousSocketChannel.open();
        channel.connect(new InetSocketAddress(HOST, PORT));

        for(int i=0;i f = channel.write(buffer);
            Integer result = f.get();
            System.out.println("write done,"+result+","+NO.get());
        }
    }
}




https://gitee.com/dyyx/work2024/blob/master/demo/aiodemo/src/main/java/demo1/server/AioServer.java