Netty5 + Protobuf 使用

1. 安装开发环境

1.1 Netty环境
　　这里我使用Netty5.0.0版本 到这里下载即可http://netty.io/ 下载netty-all-5.0.0.Alpha2.jar 这个jar包简单配置一下即可使用。
1.2 Protobuf环境
　　这个就比较麻烦了，这里说一下我的做法。 可以在这里下载最新版https://github.com/google/protobuf 或者使用 v2.6.1稳定版 https://github.com/google/protobuf/tree/v2.6.1
　　也可以在这里下载http://pkgs.fedoraproject.org/repo/pkgs/protobuf/protobuf-2.6.1.tar.bz2/
　　在这里下载对应的Protobuf-java.jar http://central.maven.org/maven2/com/google/protobuf/protobuf-java/
　　http://mvnrepository.com/artifact/com.google.protobuf/protobuf-java

1.3 Protoc 工具
　　Linux和Windows都差不多，编译源代码即可。
　　以Windows为例，打开\protobuf-2.6.1\vsprojects\protobuf.sln

　　这样生成解决方案。

　　在Debug里面这些文件是有用的

2. protobuf初始化

SubscribeReq.proto

 package netty;
 option java_package = "com.jieli.nettytest.protobuf";
 option java_outer_classname = "SubscribeReqProto";

 message SubscribeReq{
     required int32 subReqID = 1;
     required string userName = 2;
     required string productName = 3;
     repeated string address = 4;
 }

SubscribeResq.proto

 package netty;
 option java_package = "com.jieli.nettytest.protobuf";
 option java_outer_classname = "SubscribeResqProto";

 message SubscribeResq{
     required int32 subReqID = 1;
     required int32 respCode = 2;
     required string desc = 3;
 }

　　用protobuf.exe进行编译

 protoc.exe --java_out=. --cpp_out=. SubscribeReq.proto
 protoc.exe --java_out=. --cpp_out=. SubscribeResq.proto

3. Protobuf 测试

　　TestSubscribeReqProto.java

 package com.jieli.nettytest.protobuf;

 import java.util.ArrayList;
 import java.util.List;
 import com.google.protobuf.InvalidProtocolBufferException;

 public class TestSubscribeReqProto {

     private static byte[] encode(SubscribeReqProto.SubscribeReq req){
         return req.toByteArray();
     }

     private static SubscribeReqProto.SubscribeReq decode(byte[] body)
             throws InvalidProtocolBufferException {
         return SubscribeReqProto.SubscribeReq.parseFrom(body);
     }

     private static SubscribeReqProto.SubscribeReq createSubscribeReq(){
         SubscribeReqProto.SubscribeReq.Builder builder =
                 SubscribeReqProto.SubscribeReq.newBuilder();
         builder.setSubReqID(1);
         builder.setUserName("Lilinfeng");
         builder.setProductName("netty book");
         List<String> address = new ArrayList<>();
         address.add("NanJing YuHuaTai");
         address.add("beijin lilili");
         address.add("asdfasdf");
         builder.addAllAddress(address);
         return builder.build();
     }

     public static void main(String[] args) {
         try {
             SubscribeReqProto.SubscribeReq req = createSubscribeReq();
             System.out.println("befor encode:" + req.toString());
             SubscribeReqProto.SubscribeReq req2 = decode(encode(req));
             System.out.println("After decode :"+req.toString());
             System.out.println("assert equal : ==>" + req2.equals(req));
         } catch (Exception e) {
             e.printStackTrace();
         }
     }
 }

　　运行结果

　　项目目录结构

4. java-java通信例子(跟书本上是差不多一样的)

　　SubReqServer.java

 package com.jieli.nettytest.protobuf;

 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 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.protobuf.ProtobufDecoder;
 import io.netty.handler.codec.protobuf.ProtobufEncoder;
 import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
 import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;
 import io.netty.handler.logging.LogLevel;
 import io.netty.handler.logging.LoggingHandler;

 public class SubReqServer {

     public void bind(int port){
         EventLoopGroup bossGroup = new NioEventLoopGroup();
         EventLoopGroup workerGroup = new NioEventLoopGroup();
         try {
             ServerBootstrap b = new ServerBootstrap();
             b.group(bossGroup, workerGroup)
              .channel(NioServerSocketChannel.class)
              .option(ChannelOption.SO_BACKLOG, 100)
              .handler(new LoggingHandler(LogLevel.INFO))
              .childHandler(new ChannelInitializer<SocketChannel>() {
                 @Override
                 protected void initChannel(SocketChannel ch) throws Exception {
                     ch.pipeline().addLast(new ProtobufVarint32FrameDecoder());
                     //与c++通信时这里的varint32要注释掉，因为默认的protobuf是没有32位对齐的，如果要实现自动分包，那么要在C++客户端进行组装
                     ch.pipeline().addLast(new ProtobufDecoder(
                             SubscribeReqProto.SubscribeReq.getDefaultInstance()));
                     ch.pipeline().addLast(new ProtobufVarint32LengthFieldPrepender());
                     ch.pipeline().addLast(new ProtobufEncoder());
                     ch.pipeline().addLast(new SubReqServerHandler());
                 }
             });

             ChannelFuture f = b.bind(port).sync();

             f.channel().closeFuture().sync();
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             bossGroup.shutdownGracefully();
             workerGroup.shutdownGracefully();
         }
     }

     public static void main(String[] args) {
         new SubReqServer().bind(7777);
     }
 }

　　SubReqServerHandler.java

 package com.jieli.nettytest.protobuf;

 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;

 public class SubReqServerHandler extends ChannelHandlerAdapter{
     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg)
             throws Exception {
         SubscribeReqProto.SubscribeReq req = (SubscribeReqProto.SubscribeReq) msg;
         if("Lilinfeng".equalsIgnoreCase(req.getUserName())){
             System.out.println("Service accept client subscribe req:["+req.toString()+"]");
             //ctx.writeAndFlush(resp(req.getSubReqID()));
         }
     }

     private SubscribeResqProto.SubscribeResq resp(int subReqID){
         SubscribeResqProto.SubscribeResq.Builder builder =
                 SubscribeResqProto.SubscribeResq.newBuilder();
         builder.setSubReqID(subReqID);
         builder.setRespCode(0);
         builder.setDesc("Netty book order success..");
         return builder.build();
     }

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

　　SubReqClient.java

 package com.jieli.nettytest.protobuf;

 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 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.protobuf.ProtobufDecoder;
 import io.netty.handler.codec.protobuf.ProtobufEncoder;
 import io.netty.handler.codec.protobuf.ProtobufVarint32FrameDecoder;
 import io.netty.handler.codec.protobuf.ProtobufVarint32LengthFieldPrepender;
 import io.netty.handler.logging.LogLevel;
 import io.netty.handler.logging.LoggingHandler;

 public class SubReqClient {

     public void connect(int port, String host){
         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 LoggingHandler(LogLevel.INFO));
                     ch.pipeline().addLast(new ProtobufVarint32FrameDecoder());
                     ch.pipeline().addLast(new ProtobufDecoder(
                             SubscribeResqProto.SubscribeResq.getDefaultInstance()));
                     ch.pipeline().addLast(new ProtobufVarint32LengthFieldPrepender());
                     ch.pipeline().addLast(new ProtobufEncoder());
                     ch.pipeline().addLast(new SubReqClientHandler());
                 }
             });

             ChannelFuture f = b.connect(host, port).sync();

             f.channel().closeFuture().sync();
         } catch (Exception e) {
             e.printStackTrace();
         } finally {
             group.shutdownGracefully();
         }
     }

     public static void main(String[] args) {
         new SubReqClient().connect(7777, "localhost");
     }
 }

　　SubReqClientHandler.java

 package com.jieli.nettytest.protobuf;

 import java.util.ArrayList;
 import java.util.List;

 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;

 public class SubReqClientHandler extends ChannelHandlerAdapter{
     public SubReqClientHandler() {
     }

     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
         for(int i=0; i<10; i++){
             ctx.write(subReq(i));
         }
         ctx.flush();
     }

     private SubscribeReqProto.SubscribeReq subReq(int i){
         SubscribeReqProto.SubscribeReq.Builder builder =
                 SubscribeReqProto.SubscribeReq.newBuilder();
         builder.setSubReqID(i);
         builder.setUserName("Lilinfeng");
         builder.setProductName("Netty Book..");
         List<String> address = new ArrayList<>();
         address.add("NanJin LLLLLL");
         address.add("beijin lllllll");
         address.add("shenzhen jjjjjj");
         builder.addAllAddress(address);
         return builder.build();
     }

     @Override
     public void channelRead(ChannelHandlerContext ctx, Object msg)
             throws Exception {
         System.out.println("Receive server response:["+msg+"]");
     }

     @Override
     public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
         ctx.flush();
     }

 }

　　服务器运行结果

　　客户端运行结果

5. (C/C++)-java通信例子

　　本来想用mingw来实现的但是，试了几次，总是编译不过。就放弃了，使用VS2008来编译了。

　　新建一个控制台程序，配置下属性页， 下面这个图配置到protobuf源代码的src目录

　　下面这个图配置到用vs编译编译产生的中间文件，包含几个lib包的目录

　　将经过protoc.exe产生的*.h和*.cc文件放到对应的项目中

　　main.cpp代码

 #include <iostream>
 #include <windows.h>
 #include "SubscribeReq.pb.h"
 #include "SubscribeResq.pb.h"

 #pragma comment(lib, "ws2_32.lib")
 #pragma comment(lib,"libprotobuf.lib")
 #pragma comment(lib,"libprotobuf-lite.lib")

 using namespace std;
 using namespace netty;

 //打开连接
 SOCKET open_msg(char *host, int port)
 {
     //初始化Socket dll
     WSADATA wsaData;
     WORD socketVersion = MAKEWORD(,);
     if(WSAStartup(socketVersion,&wsaData)!=)
     {
         printf("Init socket dll error!");
         return -;
     }
     //创建socket
     SOCKET s = socket(AF_INET, SOCK_STREAM, ); //tcp
     if (SOCKET_ERROR == s)
     {
         printf("Create Socket Error!");
         return -;
     }
     //指定服务端的地址
     sockaddr_in server_addr;
     server_addr.sin_family = AF_INET;
     server_addr.sin_addr.S_un.S_addr = inet_addr(host);
     server_addr.sin_port = htons(port);

     char opt = ;
     int ret = setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(char));
     if(ret == -)
     {
         printf("ERROR\n");
         return -;
     }

     //连接
     if (SOCKET_ERROR == connect(s, (LPSOCKADDR)&server_addr, sizeof(server_addr)))
     {
         printf("Can Not Connect To Server IP!\n");
         return -;
     }
     return s;
 }
 //获取信息
 int recv_msg(SOCKET s,char *msg,int size)
 {
     int ret = recv(s,msg,size,);
     if(ret == SOCKET_ERROR)
     {
         printf("Recv Error.\n");
         return -;
     }
     return ret;
 }
 //发送信息
 int send_msg(SOCKET s,char *msg,int size)
 {
     int ret = send(s,msg,size,);
     if(ret == SOCKET_ERROR)
     {
         printf("Send Error.\n");
         return -;
     }
     return ret;
 }
 //关闭连接
 int close_msg(SOCKET s)
 {
     closesocket(s);
     return ;
 }

 int main()
 {
     SubscribeReq req ;
     req.set_username("Lilinfeng");
     req.add_address("asdf");
     req.set_subreqid();
     req.set_productname("laskjdfk111");

     SOCKET s = open_msg("127.0.0.1", );

     char msg[] = {};
     req.SerializePartialToArray(msg, );

     cout<<req.GetCachedSize()<<endl;
     send_msg(s, msg, req.GetCachedSize());

     close_msg(s);

     system("pause");
     return ;
 }

　　然后编译运行就可以发送protobuf对象到java服务器端，运行后服务器出现这个结果

　　找了很久原因，原来是服务器SubReqServer.java中的ProtobufVarint32***解码器对Protobuf包进行处理，导致格式不一致，解决的办法是注释掉这两行，不过这样又会产生书本上说到的问题，会出现粘包。我能想到的办法是1.在C++客户端中进行修改，使之对应到Java中对齐格式，这个要看源代码。 2.发送的包前面增加包头，然后包头信息描述Protobuf大小。

参考资料

　　Netty权威指南 – 第八章 Google Protobuf 编解码
　　http://blog.****.net/majianfei1023/article/details/45371743
　　http://www.cnblogs.com/lidabo/p/3911456.html

本文地址: http://www.cnblogs.com/wunaozai/p/5236494.html