Netty进行文件传输

本次是利用TCP在客户端发送文件流，服务端就接收流，写入相应的文件。

实验的源文件是一个图片，假设地址是D:\\Koala.jpg，接收保存后的图片为D:\\test.jpg

原理就是将文件读取成byte，通过bytebuffer发送即可

客户端

package net.xjdsz.file;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
/**
 * Created by dingshuo on 2017/7/6.
 */
public class UploadClient {
    public static void main(String[] args) throws Exception{
        UploadClient client=new UploadClient();
        client.connect();
    }
    public void connect(){
        EventLoopGroup group=new NioEventLoopGroup();
        try{
            Bootstrap b=new Bootstrap();
            b.group(group).channel(NioSocketChannel.class)
                    .option(ChannelOption.TCP_NODELAY,true)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter(){
                                @Override
                                public void channelActive(ChannelHandlerContext ctx) throws Exception {
                                    ByteBuf msg;
                                    InputStream in = new FileInputStream("D:\\Koala.jpg");
                                    ByteArrayOutputStream out = new ByteArrayOutputStream();
                                    byte[] buffer = new byte[1024 * 100];
                                    int n = 0;
                                    while ((n = in.read(buffer)) != -1) {
                                        msg= Unpooled.buffer(buffer.length);
                                        //这里读取到多少，就发送多少，是为了防止最后一次读取没法满填充buffer，
                                        //导致将buffer中的处于尾部的上一次遗留数据也发送走
                                        msg.writeBytes(buffer,0,n);
                                        ctx.writeAndFlush(msg);
                                        msg.clear();
                                    }
                                    System.out.println(n);
                                }
                            });
                        }
                    });
            ChannelFuture f=b.connect("127.0.0.1",20000).sync();
            f.channel().closeFuture().sync();
        }catch (Exception e){
        }finally {
            group.shutdownGracefully();
        }
    }
}

服务端

package net.xjdsz.file;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
/**
 * Created by dingshuo on 2017/7/6.
 */
public class UploadServer {
    public void bind(int port) throws Exception{
        EventLoopGroup bossGroup=new NioEventLoopGroup();
        EventLoopGroup workerGroup=new NioEventLoopGroup();
        try{
            ServerBootstrap b=new ServerBootstrap();
            b.group(bossGroup,workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG,1024)
                    .handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter(){
                                @Override
                                public void channelActive(ChannelHandlerContext ctx) throws Exception {
                                    super.channelActive(ctx);
                                }
                                @Override
                                public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                                    super.channelInactive(ctx);
                                }
                                @Override
                                public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                                    String path="D:\\test.jpg";
                                    File file=new File(path);
                                    if(!file.exists()){
                                        file.createNewFile();
                                    }
                                    FileOutputStream fos=new FileOutputStream(file,true);
//                                    BufferedOutputStream bufferedOutputStream=new BufferedOutputStream(fos);
                                    ByteBuf buf=(ByteBuf)msg;
                                    byte[] bytes=new byte[buf.readableBytes()];
                                    buf.readBytes(bytes);
                                    System.out.println("本次接收内容长度：" + bytes.length);
                                    try {
//                                        bufferedOutputStream.write(bytes, 0, bytes.length);
//                                        buf.release();
                                        fos.write(bytes);
                                        fos.flush();
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    }
                                }
                            });
                        }
                    });
            //绑定端口，同步等待成功
            ChannelFuture f=b.bind(port).sync();
            //等待服务端监听端口关闭
            f.channel().closeFuture().sync();
        }finally {
            //退出，释放资源
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }
    public static void main(String[] args) throws Exception{
        UploadServer uploadServer=new UploadServer();
        uploadServer.bind(20000);
    }
}