Netty进行文件传输

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我是靠谱客的博主无限绿草，最近开发中收集的这篇文章主要介绍Netty进行文件传输，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

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);
}
}