Netty with protobuf（二）

http://my.oschina.net/xinxingegeya/blog/295031

上一篇了解了protobuf，现在结合netty做一个例子。

关键就是配置netty的编解码器，因为netty提供了protobuf的编解码器，所以我们可以很容易的使用netty提供的编解码器使用protobuf数据交换协议进行通信。。

下面是示例代码，对于了解的netty的同学应该不难看懂。

服务器端程序：

ProtobufNettyServer.java

package com.example.tutorial;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import telnet.TelnetServerInitializer;

/**
 * Created with IntelliJ IDEA.
 * User: ASUS
 * Date: 14-7-22
 * Time: 下午8:26
 * To change this template use File | Settings | File Templates.
 */
public class ProtobufNettyServer {
    private final int port;

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

    public void run() throws Exception {
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ProtobufNettyServerInitializer());

            b.bind(port).sync().channel().closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = Integer.parseInt(args[0]);
        } else {
            port = 8999;
        }
        new ProtobufNettyServer(port).run();
    }

}

ProtobufNettyServerInitializer.java

package com.example.tutorial;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.LengthFieldPrepender;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.codec.protobuf.ProtobufEncoder;

/**
 * Created with IntelliJ IDEA.
 * User: ASUS
 * Date: 14-7-22
 * Time: 下午8:46
 * To change this template use File | Settings | File Templates.
 */
public class ProtobufNettyServerInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast("frameEncoder", new LengthFieldPrepender(4));
        pipeline.addLast("protobufEncoder", new ProtobufEncoder());
        pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(1048576, 0, 4, 0, 4));
        pipeline.addLast("protobufDecoder", new ProtobufDecoder(
                AddressBookProtos.AddressBook.getDefaultInstance()));
        pipeline.addLast("protobufHandler", new ProtobufNettyServerHandler());
    }
}

ProtobufNettyServerHandler.java

package com.example.tutorial;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

/**
 * Created with IntelliJ IDEA.
 * User: ASUS
 * Date: 14-7-22
 * Time: 下午9:19
 * To change this template use File | Settings | File Templates.
 */
public class ProtobufNettyServerHandler extends SimpleChannelInboundHandler<AddressBookProtos.AddressBook> {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, AddressBookProtos.AddressBook msg) throws Exception {
        System.out.println("服务器端接受到的数据是：" + msg.toString());
        AddressBookProtos.Person person = msg.getPerson(0);

        //把电话薄中的第一个人返回给客户端
        ctx.channel().writeAndFlush(person);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);    //To change body of overridden methods use File | Settings | File Templates.
    }
}

客户端程序：

ProtobufNettyClient.java

package com.example.tutorial;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * Created with IntelliJ IDEA.
 * User: ASUS
 * Date: 14-7-22
 * Time: 下午9:18
 * To change this template use File | Settings | File Templates.
 */
public class ProtobufNettyClient {

    private final String host;
    private final int port;

    public ProtobufNettyClient(String host, int port) {
        this.host = host;
        this.port = port;
    }

    public void run() throws Exception {
        EventLoopGroup group = new NioEventLoopGroup();
        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ProtobufNettyClientInitializer());

            ChannelFuture f = b.connect(host, port).sync();
            f.channel().closeFuture().sync();
        } finally {
            group.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        // Print usage if no argument is specified.
        if (args.length != 2) {
            System.err.println("Usage: " + ProtobufNettyClient.class.getSimpleName() + " <host> <port>");
            return;
        }
        // Parse options.
        String host = args[0];
        int port = Integer.parseInt(args[1]);
        new ProtobufNettyClient(host, port).run();
    }
}

ProtobufNettyClientInitializer.java

package com.example.tutorial;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.LengthFieldPrepender;
import io.netty.handler.codec.protobuf.ProtobufDecoder;
import io.netty.handler.codec.protobuf.ProtobufEncoder;

/**
 * Created with IntelliJ IDEA.
 * User: ASUS
 * Date: 14-7-22
 * Time: 下午9:18
 * To change this template use File | Settings | File Templates.
 */
public class ProtobufNettyClientInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast("frameEncoder", new LengthFieldPrepender(4));
        pipeline.addLast("protobufEncoder", new ProtobufEncoder());
        pipeline.addLast("frameDecoder", new LengthFieldBasedFrameDecoder(1048576, 0, 4, 0, 4));
        pipeline.addLast("protobufDecoder", new ProtobufDecoder(
                AddressBookProtos.Person.getDefaultInstance()));
        pipeline.addLast("protobufHandler", new ProtobufNettyClientHandler());
    }
}

ProtobufNettyClientHandler.java

package com.example.tutorial;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

public class ProtobufNettyClientHandler extends SimpleChannelInboundHandler<AddressBookProtos.Person> {

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        AddressBookProtos.AddressBook.Builder addressBookBuilder = AddressBookProtos.AddressBook.newBuilder();


        AddressBookProtos.Person.PhoneNumber.Builder phoneNumberBuilder = AddressBookProtos.
                Person.PhoneNumber.newBuilder();

        AddressBookProtos.Person.Builder personBuilder = AddressBookProtos.Person.newBuilder();
        personBuilder.setEmail("744858873@qq.com").setId(123456789).setName("hellolyx");
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330465").setType(AddressBookProtos.Person.PhoneType.HOME).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330466").setType(AddressBookProtos.Person.PhoneType.WORK).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330467").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330468").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330469").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.setPhone(0, phoneNumberBuilder.setNumber("110").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());

        //向电话薄里添加一个联系人
        addressBookBuilder.addPerson(personBuilder.build());

        personBuilder.setEmail("78655676@qq.com").setId(123456789).setName("hellodog");
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330465").setType(AddressBookProtos.Person.PhoneType.HOME).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330466").setType(AddressBookProtos.Person.PhoneType.WORK).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330467").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330468").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330469").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.setPhone(0, phoneNumberBuilder.setNumber("119").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());

        //再次向电话薄里添加一个联系人
        addressBookBuilder.addPerson(personBuilder.build());

        personBuilder.setEmail("78655676@qq.com").setId(123456789).setName("hellopig");
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330465").setType(AddressBookProtos.Person.PhoneType.HOME).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330466").setType(AddressBookProtos.Person.PhoneType.WORK).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330467").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330468").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.addPhone(phoneNumberBuilder.setNumber("15840330469").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());
        personBuilder.setPhone(0, phoneNumberBuilder.setNumber("124").setType(AddressBookProtos.Person.PhoneType.MOBILE).build());

        addressBookBuilder.addPerson(personBuilder.build());
        /**
         * 一个电话薄里添加了三个人
         */
        AddressBookProtos.AddressBook addressBook = addressBookBuilder.build();
        ctx.channel().writeAndFlush(addressBook);
    }

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, AddressBookProtos.Person msg) throws Exception {
        //打印接受到的数据
        System.out.println(msg);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);    //To change body of overridden methods use File | Settings | File Templates.
    }
}

这就是全部的代码了。关键就是编解码的配置部分，

客户端的解码器一定要配置正确：

pipeline.addLast("protobufDecoder", new ProtobufDecoder(
                AddressBookProtos.Person.getDefaultInstance()));

===END===

来源：oschina

链接：https://my.oschina.net/u/1469576/blog/295032