语法

Message

syntax = "proto3";

message SearchRequest {
  string query = 1;
  int32 page_number = 2;
  int32 result_per_page = 3;
}

Field Rules

repeated querys = 1;

Enumerations

message SearchRequest {
  string query = 1;
  int32 page_number = 2;
  int32 result_per_page = 3;
  enum Corpus {
    UNIVERSAL = 0;
    WEB = 1;
    IMAGES = 2;
    LOCAL = 3;
    NEWS = 4;
    PRODUCTS = 5;
    VIDEO = 6;
  }
  Corpus corpus = 4;
}

Other Message Types

message SearchResponse {
  repeated Result results = 1;
}

message Result {
  string url = 1;
  string title = 2;
  repeated string snippets = 3;
}

Importing

import "myproject/other_protos.proto";

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
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
uint32	Uses variable-length encoding.	uint32	int[1]	int/long[3]	uint32	Fixnum or Bignum	(as required)	uint
uint64	Uses variable-length	encoding.	uint64	long[1]	int/long[3]	uint64	Bignum	ulong
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
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
fixed32	Always four bytes. More efficient than uint32 if values are often greater than	228.	uint32	int[1]	int	uint32	Fixnum or Bignum (as required)	uint
fixed64	Always eight bytes. More efficient than uint64 if values are often greater than	256.	uint64	long[1]	int/long[3]	uint64	Bignum	ulong
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
bytes	May contain any arbitrary sequence of bytes.	string	ByteString	str	[]byte	String	(ASCII-8BIT)	ByteString

默认值

strings	bytes	bools	numeric types	enums	message fields
empty string	empty bytes	false	zero	first defined enum value,must be 0	language-dependent

选项

• java_package

  option java_package = "com.example.foo";
  

• java_multiple_files

  option java_multiple_files = true;
  

• java_outer_classname

  option java_outer_classname = "Ponycopter";
  

• optimize_for

  • SPEED (default)

  • CODE_SIZE

  • LITE_RUNTIME

    option optimize_for = CODE_SIZE;
    

• cc_enable_arenas

• objc_class_prefix

• deprecated

    int32 old_field = 6 [deprecated=true];
  

编译

protoc --proto_path=IMPORT_PATH --cpp_out=DST_DIR --java_out=DST_DIR --python_out=DST_DIR --go_out=DST_DIR --ruby_out=DST_DIR --javanano_out=DST_DIR --objc_out=DST_DIR --csharp_out=DST_DIR path/to/file1.proto path/to/file2.proto path/to/file3.proto

选项	描述
--proto_path	编译环境的工作目录，跟proto文件中的import有关，跟后面的参数无关。
--<language>_out	编译后文件输出目录
<message.proto>	需要编译的proto文件

Done