io.netty.example.filetransfer.FileServer Maven / Gradle / Ivy

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/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.example.filetransfer;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.BufType;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.util.CharsetUtil;

import java.io.File;
import java.io.FileInputStream;

/**
 * Server that accept the path of a file an echo back its content.
 */
public class FileServer {

    private final int port;

    public FileServer(int port) {
        this.port = port;
    }

    public void run() throws Exception {
        // Configure the server.
        ServerBootstrap b = new ServerBootstrap();
        try {
            b.group(new NioEventLoopGroup(), new NioEventLoopGroup())
             .channel(NioServerSocketChannel.class)
             .option(ChannelOption.SO_BACKLOG, 100)
             .handler(new LoggingHandler(LogLevel.INFO))
             .childHandler(new ChannelInitializer() {
                 @Override
                 public void initChannel(SocketChannel ch) throws Exception {
                     ch.pipeline().addLast(
                             new StringEncoder(BufType.BYTE, CharsetUtil.UTF_8),
                             new LineBasedFrameDecoder(8192),
                             new StringDecoder(CharsetUtil.UTF_8),
                             new FileHandler());
                 }
             });

            // Start the server.
            ChannelFuture f = b.bind(port).sync();

            // Wait until the server socket is closed.
            f.channel().closeFuture().sync();
        } finally {
            // Shut down all event loops to terminate all threads.
            b.shutdown();
        }
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = Integer.parseInt(args[0]);
        } else {
            port = 8080;
        }
        new FileServer(port).run();
    }

    private static final class FileHandler extends ChannelInboundMessageHandlerAdapter {
        @Override
        public void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception {
            File file = new File(msg);
            if (file.exists()) {
                if (!file.isFile()) {
                    ctx.write("Not a file: " + file + '\n');
                    return;
                }
                ctx.write(file + " " + file.length() + '\n');
                ctx.sendFile(new DefaultFileRegion(new FileInputStream(file).getChannel(), 0, file.length()));
                ctx.write("\n");
            } else {
                ctx.write("File not found: " + file + '\n');
            }
        }

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