netty服务端长链接和短链接java代码实现

下面是Netty服务端长连接和短连接的Java代码实现示例：

1. 长连接

public class LongConnectionServer {
    public static void main(String[] args) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup)
                     .channel(NioServerSocketChannel.class)
                     .childHandler(new ChannelInitializer<SocketChannel>() {
                         @Override
                         protected void initChannel(SocketChannel ch) throws Exception {
                             ChannelPipeline pipeline = ch.pipeline();
                             pipeline.addLast(new LongConnectionServerHandler());
                         }
                     })
                     .option(ChannelOption.SO_BACKLOG, 128)
                     .childOption(ChannelOption.SO_KEEPALIVE, true);

            ChannelFuture future = bootstrap.bind(8080).sync();
            future.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }
}

public class LongConnectionServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        // 处理请求
        // ...

        // 返回响应
        ByteBuf response = Unpooled.copiedBuffer("Hello World".getBytes());
        ctx.write(response);
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

2. 短连接

public class ShortConnectionServer {
    public static void main(String[] args) throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup)
                     .channel(NioServerSocketChannel.class)
                     .childHandler(new ChannelInitializer<SocketChannel>() {
                         @Override
                         protected void initChannel(SocketChannel ch) throws Exception {
                             ChannelPipeline pipeline = ch.pipeline();
                             pipeline.addLast(new ShortConnectionServerHandler());
                         }
                     })
                     .option(ChannelOption.SO_BACKLOG, 128);

            ChannelFuture future = bootstrap.bind(8080).sync();
            future.channel().closeFuture().sync();
        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }
}

public class ShortConnectionServerHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        // 处理请求
        // ...

        // 返回响应
        ByteBuf response = Unpooled.copiedBuffer("Hello World".getBytes());
        ctx.write(response);
        ctx.flush();
        ctx.close();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

以上示例中，LongConnectionServer和LongConnectionServerHandler实现了长连接的服务端和处理器，ShortConnectionServer和ShortConnectionServerHandler实现了短连接的服务端和处理器。需要注意的是，长连接需要在childOption中设置SO_KEEPALIVE选项来保持连接，短连接中不需要。