protobuf在Python和Java之间通信测试

cixiren

一 准备protobuf环境
1 下载protobuf-2.6.1,解压，进入vsprojects目录，用VC打开工程，编译出 protoc.exe
2 生成.proto文件
message TestMsg
{
   required string name = 1;
}
放到自己的目录，此例子中放到了f:根目录下。
然后执行:
protoc.exe -I=f:\ --python_out=f:\ f:\TestMsgProto.proto
生成 TestMsgProto_pb2.py，给python用
protoc.exe -I=f:\ --java_out=f:\ f:\TestMsgProto.proto
生成TestMsgProto.java，给java工程用

3 生成对应c++,python,java的class文件

二 python
1 copy protoc.exe到protobuf-2.6.1/python
2 python setup.py build
3 python setup.py install
4 测试用客户端代码:

import google.protobuf
import TestMsgProto_pb2
import socket
address = ('127.0.0.1', 8800)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(address)
msg = TestMsgProto_pb2.TestMsg()
msg.name='name'
test_str = msg.SerializeToString()
print test_str
ret=s.send(test_str)
print ret
s.close()


三 java环境
可参考：https://github.com/vincepeng/gameNettyDemo
主要看 https://github.com/vincepeng/gameNettyDemo/tree/master/GameNettyServer/bin/com/server/java/netty
这下面的几个文件，可以直接放到自己工程里，或者自己稍改动一下。

注意事项：
新建myeclipse maven工程，pom.xml增加：
<dependency>
   <groupId>io.netty</groupId>
   <artifactId>netty-all</artifactId>
   <version>4.0.30.Final</version>
   <scope>compile</scope>
    </dependency>
<dependency>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-java</artifactId>
   <version>2.6.1</version>
</dependency>


然后，主要处理:decoder和encoder,相比gameNettyDemo做了些减化，下面是做过修改的代码:
//NettyMsgEncoder
public class NettyMsgEncoder extends MessageToByteEncoder<String> {
@Override
protected void encode(ChannelHandlerContext ctx, String name, ByteBuf byteBuf) throws Exception {

TestMsgProto.TestMsg.Builder builder = TestMsgProto.TestMsg.newBuilder();
builder.setName(name);

TestMsgProto.TestMsg msg = builder.build();
byteBuf.writeBytes(msg.toByteArray());
}
}


// NettyMsgDecoder
public class NettyMsgDecoder extends LengthFieldBasedFrameDecoder {
//以下两个构造函数，在本例中用不上
public NettyMsgDecoder(ByteOrder byteOrder, int maxFrameLength, int lengthFieldOffset, int lengthFieldLength, int lengthAdjustment, int initialBytesToStrip, boolean failFast) {
super(byteOrder, maxFrameLength, lengthFieldOffset, lengthFieldLength, lengthAdjustment, initialBytesToStrip, failFast);
}

public NettyMsgDecoder() {
this(ByteOrder.BIG_ENDIAN, 100000, 0, 4, 2, 4, true);
}

@Override
protected Object decode(ChannelHandlerContext ctx, ByteBuf byteBuf) throws Exception {
if (byteBuf != null && byteBuf.readableBytes()>0){
int len = byteBuf.readableBytes();
byte[] data = new byte[len];
byteBuf.readBytes(data);
TestMsgProto.TestMsg msg = TestMsgProto.TestMsg.parseFrom(data);


//return msg.getName();
return msg;
}
return null;
}


}


//NettyServerInitializer
public class NettyServerInitializer extends ChannelInitializer<SocketChannel> {


@Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast("decoder", new NettyMsgDecoder())// 解码器
.addLast("encoder", new NettyMsgEncoder())// 编码器
.addLast("handler", new ServerHanlder());
}
}
//ServerHanlder
@Sharable
public class ServerHanlder extends SimpleChannelInboundHandler<TestMsgProto.TestMsg> {
@Override
protected void channelRead0(ChannelHandlerContext ctx, TestMsgProto.TestMsg msg)
throws Exception {
if (msg != null)
System.out.println(msg.getName());

}
}

//SimpleChatServer
public class SimpleChatServer {
private int port;


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


    public void run() throws Exception {


        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             //.childHandler(new SimpleChatServerInitializer())
             .childHandler(new NettyServerInitializer())
             .option(ChannelOption.SO_BACKLOG, 128)         
             .childOption(ChannelOption.SO_KEEPALIVE, true);


            ChannelFuture f = b.bind(port).sync(); // (7)
            f.channel().closeFuture().sync();


        } finally {
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();


            System.out.println("SimpleChatServer 关闭了");
        }
    }
}


然后，在Myeclipse里运行java服务器程序
再启动python 远程连接，看接收情况。
从代码上看，小项目用python是多么方便。

上面例子只有java netty的server和python的client .
稍做修改，就能实现python的server和java的client，复杂的依然复杂，简洁的依然简洁。