python 怎么关闭 打开的 shelll 脚本

很高兴回答您的问题。下面是Java Netty实现将文件从一个路径发送到另一个路径的示例代码：

发送端代码：

// 需要导入相关包
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.serialization.ObjectEncoder;

public class MyNettyClient {
    public void run() throws InterruptedException, FileNotFoundException {
        String host = "127.0.0.1";  // 服务器地址
        int port = 8080;  // 服务器端口号

        EventLoopGroup workerGroup = new NioEventLoopGroup();

        try {
            Bootstrap b = new Bootstrap(); // 启动NIO客户端的辅助启动类
            b.group(workerGroup); // 传递了一个NioEventLoopGroup实例以处理事件的处理
            b.channel(NioSocketChannel.class); // 使用NioSocketChannel来作为连接用的channel类
            b.option(ChannelOption.SO_KEEPALIVE, true); // 设置客户端套接字参数
            b.handler(new ChannelInitializer<SocketChannel>() { // 有连接到服务端的时候，在处理连接的数据

                @Override
                protected void initChannel(SocketChannel ch) throws Exception {
                    ChannelPipeline pipeline = ch.pipeline();
                    // 为pipeline添加一个ObjectEncoder，以将Object转换为ByteBuf用于发送
                    pipeline.addLast("encoder", new ObjectEncoder());
                }
            });

            // 启动客户端连接服务端
            ChannelFuture f = b.connect(host, port).sync();

            // 创建文件输入流
            File file = new File("D:\\test.txt");
            FileInputStream inputStream = new FileInputStream(file);
            byte[] bytes = new byte[(int) file.length()];
            inputStream.read(bytes);
            inputStream.close();

            // 发送文件，将文件内容封装到FileMessage对象中，通过byteBuf发送到服务端
            FileMessage fileMessage = new FileMessage();
            fileMessage.setFileName(file.getName());
            fileMessage.setContent(bytes);
            ChannelFuture future = f.channel().writeAndFlush(Unpooled.copiedBuffer(fileMessage.serialize()));
            future.sync();

            // 等待客户端通道关闭
            f.channel().closeFuture().sync();

        } finally {
            // 优雅的关闭客户端
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws InterruptedException, FileNotFoundException {
        new MyNettyClient().run();
    }
}

接收端代码：

// 需要导入相关包
import java.io.File;
import java.io.FileOutputStream;
import java.util.UUID;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.serialization.ClassResolver;
import io.netty.handler.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;

public class MyNettyServer {
    public void run() throws Exception {
        int port = 8080; // 定义服务端监听端口

        EventLoopGroup bossGroup = new NioEventLoopGroup(); // 创建boss线程组用于处理连接工作
        EventLoopGroup workerGroup = new NioEventLoopGroup(); // 创建worker线程组用于处理数据读写

        try {
            ServerBootstrap b = new ServerBootstrap(); // 创建服务端启动辅助类
            b.group(bossGroup, workerGroup) // 设置使用的group
             .channel(NioServerSocketChannel.class) // 指明使用的channel类型
             .option(ChannelOption.SO_BACKLOG, 128) // 设置客户端连接队列长度
             .childOption(ChannelOption.SO_KEEPALIVE, true) // 设置连接状态检查
             .childHandler(new ChannelInitializer<SocketChannel>() { // worker线程组的处理类

                @Override
                protected void initChannel(SocketChannel ch) throws Exception {
                    ChannelPipeline pipeline = ch.pipeline();
                    // 添加自定义handler处理文件读写
                    pipeline.addLast(new MyServerHandler());
                   // 反序列化，将ByteBuf转换为Object对象，采用LengthFieldBasedFrameDecoder解决半包读写的问题
                    pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4));
                    pipeline.addLast("decoder", new ObjectDecoder(Integer.MAX_VALUE,
                            ClassResolvers.weakCachingConcurrentResolver(null)));
                }
            });

            // 绑定端口，开始接收进来的连接
            ChannelFuture f = b.bind(port).sync();

            // 等待服务器socket关闭
            f.channel().closeFuture().sync();

        } finally {
            // 关闭线程池资源
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        new MyNettyServer().run();
    }
}

// 自定义Handler，用于处理文件的读写
class MyServerHandler extends ChannelInboundHandlerAdapter {
    // 文件存储路径
    private static final String DIRECTORY = "D:\\Netty\\server\\";

    // 文件名
    private String fileName;

    // 文件内容
    private byte[] content;

    // 文件内容长度
    private int contentLength;

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        if (msg instanceof ByteBuf) {
            ByteBuf byteBuf = (ByteBuf)msg;
            
            // 判断是否已经读取到文件名
            if (fileName == null) {
                // 读取文件名
                int fileNameLength = byteBuf.readInt();
                byte[] bytes = new byte[fileNameLength];
                byteBuf.readBytes(bytes);
                fileName = new String(bytes);
            }
            // 判断是否已经读取到文件内容的长度
            if (content == null && byteBuf.readableBytes() >= 4) {
                contentLength = byteBuf.readInt();
                content = new byte[contentLength];
            }

            // 读取文件内容
            if (content != null && byteBuf.readableBytes() >= contentLength) {
                byteBuf.readBytes(content);
                // 写入保存到本地
                File file = new File(DIRECTORY + fileName);
                if (!file.exists()) {
                    file.createNewFile();
                }
                FileOutputStream fileOutputStream = new FileOutputStream(file);
                fileOutputStream.write(content, 0, contentLength);
                fileOutputStream.flush();
                fileOutputStream.close();
                ctx.close();
            }
        }
    }

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

// 定义文件消息承载类
class FileMessage implements java.io.Serializable {

    private static final long serialVersionUID = -6247471178633849179L;

    // 文件名
    private String fileName;

    // 文件内容
    private byte[] content;

    public String getFileName() {
        return fileName;
    }

    public void setFileName(String fileName) {
        this.fileName = fileName;
    }

    public byte[] getContent() {
        return content;
    }

    public void setContent(byte[] content) {
        this.content = content;
    }

    // 序列化为ByteBuf，用于网络传输
    public ByteBuf serialize() {
        int fileNameLength = fileName.getBytes().length;
        int contentLength = content.length;
        ByteBuf buf = Unpooled.buffer(4 + fileNameLength + 4 + contentLength);
        buf.writeInt(fileNameLength);
        buf.writeBytes(fileName.getBytes());
        buf.writeInt(contentLength);
        buf.writeBytes(content);
        return buf;
    }
}

以上是Java Netty实现将文件从一个路径发送到另一个路径的示例代码，您可以根据实际需求进行参考和修改。