用Netty实现一个简单全双工通信
如题，需要注意在ByteBuf使用的过程中要使用buf.retain()保证buf引用计数大于0，才能够正常使用否则会报异常，原因是pipeline上的handler都是使用NIO线程执行的，因此使用buf的handler和tail handler（最后调用buf release的handler）是不同的线程，因此是异步的就会出现上面的问题
EchoServer.class
/**
* @description: some desc
* @author: admin
* @email: 819574539@qq.com
* @date: 2023/11/20 21:16
*/
@Slf4j
public class EchoServer {
public static void main(String[] args) {
new ServerBootstrap()
.group(new NioEventLoopGroup())
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel ch) throws Exception {
ch.pipeline()
.addLast(new ChannelInboundHandlerAdapter() {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof ByteBuf) {
var buf = (ByteBuf) msg;
var str = buf.toString(Charset.defaultCharset());
log.debug(str);
buf.retain();
ctx.writeAndFlush(ByteBufAllocator.DEFAULT.buffer().writeBytes(("Hello, I'm Server:" + str).getBytes()));
}
super.channelRead(ctx, msg);
}
});
}
}).bind(8080);
}
}
EchoClient.class
/**
* @description: some desc
* @author: admin
* @email: 819574539@qq.com
* @date: 2023/11/20 21:16
*/
@Slf4j
public class EchoClient {
public static void main(String[] args) throws InterruptedException {
var channelFuture = new Bootstrap()
.group(new NioEventLoopGroup())
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<NioSocketChannel>() {
@Override
protected void initChannel(NioSocketChannel ch) throws Exception {
ch.pipeline().addLast(new StringEncoder())
.addLast(new ChannelInboundHandlerAdapter() {
@Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
if (msg instanceof ByteBuf) {
var buf = (ByteBuf) msg;
buf.retain();
log.debug(buf.toString(Charset.defaultCharset()));
}
super.channelRead(ctx, msg);
}
});
}
}).connect(new InetSocketAddress(8080));
var channel = channelFuture.sync()
.channel();
while (true) {
Scanner sc = new Scanner(System.in);
var input = sc.next();
if ("q".equals(input)) {
break;
}
channel.writeAndFlush(input);
}
}
}