ProtoBuf学习之"Hello World"

1、下载对应的包文件，比如我这里下载的是protoc-3.6.1-win32.zip，解压后将其bin路径加入到系统的PATH环境变量中；

      在cmd窗口中执行protoc --version来检查protoc是否正确安装；

2、编写protoBuf文件：

 1 syntax = "proto2";
 2 
 3 package protocol;
 4 
 5 option java_package = "com.demo.prototest";
 6 option java_outer_classname = "BaseRequestProto";
 7 
 8 message RequestProtocol {
 9     required int32 requestId = 2;
10     required string regMsg = 1;
11 }

 1 syntax = "proto2";
 2 
 3 package protocol;
 4 
 5 option java_package = "com.demo.prototest";
 6 option java_outer_classname = "BaseResponseProto";
 7 
 8 message ResponseProtocol {
 9     required int32 responseId = 2;
10     required string resMsg = 1;
11 }

3、编译proto文件：

          protoc --java_out=/dev BaseRequestProto.proto BaseResponseProto.proto

protoc 命令将刚才定义的协议格式转换为 Java 代码，并生成在 /dev 目录。

4、引入POM文件：

1 <dependency>
2     <groupId>com.google.protobuf</groupId>
3     <artifactId>protobuf-java</artifactId>
4     <version>3.4.0</version>
5 </dependency>

5、实现protoBuf编码解码测试代码：

 1 public static void main(String[] args) throws InvalidProtocolBufferException {
 2     BaseRequestProto.RequestProtocol protocol = BaseRequestProto.RequestProtocol.newBuilder()
 3             .setRequestId(123)
 4             .setRegMsg("hello, protobuf and world")
 5             .build();
 6 
 7     byte[] encode = encode(protocol);
 8 
 9     BaseRequestProto.RequestProtocol parseFrom = decode(encode);
10 
11     System.out.println(protocol.toString());
12     System.out.println(protocol.toString().equals(parseFrom.toString()));
13 }
14 
15 public static byte[] encode(BaseRequestProto.RequestProtocol protocol){
16     return protocol.toByteArray() ;
17 }
18 
19 public static BaseRequestProto.RequestProtocol decode(byte[] bytes) throws InvalidProtocolBufferException {
20     return BaseRequestProto.RequestProtocol.parseFrom(bytes);
21 }