protobuf协议java版本使用说明

超、凢脫俗 2022-05-19 10:06 538阅读 0赞

### 1. 初始话协议字段 ###

xxx .proto

syntax = "proto3"; //protobuf版本
    
    option java_package = "com.xxx.protobuf"; //生成java代码的数据包路径
    option java_outer_classname = "XxxProtocol"; //java类名
    
    message Xxx { //具体协议
    
        string id = 1; 
    
    }

### 2. 代码生成 ###

[protoc.exe下载地址][protoc.exe]

windows下借助protoc.exe的生成java代码
    
    protoc --proto_path=./ --java_out=d:\xxx\src\main\java xxx .proto

### 3. 字段类型 ###

.proto Type Notes   C++ Type    Java Type   Python Type[2]  Go Type Ruby Type   C# Type PHP Type
    double      double  double  float   float64 Float   double  float
    float       float   float   float   float32 Float   float   float
    int32   Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead. int32   int int int32   Fixnum or Bignum (as required)  int integer
    int64   Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead. int64   long    int/long[3] int64   Bignum  long    integer/string[5]
    uint32  Uses variable-length encoding.  uint32  int[1]  int/long[3] uint32  Fixnum or Bignum (as required)  uint    integer
    uint64  Uses variable-length encoding.  uint64  long[1] int/long[3] uint64  Bignum  ulong   integer/string[5]
    sint32  Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s.    int32   int int int32   Fixnum or Bignum (as required)  int integer
    sint64  Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s.    int64   long    int/long[3] int64   Bignum  long    integer/string[5]
    fixed32 Always four bytes. More efficient than uint32 if values are often greater than 228. uint32  int[1]  int/long[3] uint32  Fixnum or Bignum (as required)  uint    integer
    fixed64 Always eight bytes. More efficient than uint64 if values are often greater than 256.    uint64  long[1] int/long[3] uint64  Bignum  ulong   integer/string[5]
    sfixed32    Always four bytes.  int32   int int int32   Fixnum or Bignum (as required)  int integer
    sfixed64    Always eight bytes. int64   long    int/long[3] int64   Bignum  long    integer/string[5]
    bool        bool    boolean bool    bool    TrueClass/FalseClass    bool    boolean
    string A string must always contain UTF-8 encoded or 7-bit ASCII text. string  String  str/unicode[4]  string  String (UTF-8)  string  string
    bytes   May contain any arbitrary sequence of bytes.    string  ByteString  str []byte  String (ASCII-8BIT) ByteString  string

### 4. 使用pom依赖 ###

<dependency>
       <groupId>com.google.protobuf</groupId>
         <artifactId>protobuf-java</artifactId>
         <version>3.2.0</version>
     </dependency>
            
     <dependency>
           <groupId>com.googlecode.protobuf-java-format</groupId>
           <artifactId>protobuf-java-format</artifactId>
           <version>1.4</version>
     </dependency>

[protoc.exe]: https://github.com/google/protobuf/tags