protocol buffer基本科普

.proto Type  Notes  C++ Type  Java Type  Python Type[2]  Go Type  Ruby Type  C# Type  PHP Type  Dart Type
double    double  double  float  float64  Float  double  float  double
float    float  float  float  float32  Float  float  float  double
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  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  integer/string[5]  Int64
uint32  Uses variable-length encoding.  uint32  int[1]  int/long[3]  uint32  Fixnum or Bignum (as required)  uint  integer  int
uint64  Uses variable-length encoding.  uint64  long[1]  int/long[3]  uint64  Bignum  ulong  integer/string[5]  Int64
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  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  integer/string[5]  Int64
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  int
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]  Int64
sfixed32  Always four bytes.  int32  int  int  int32  Fixnum or Bignum (as required)  int  integer  int
sfixed64  Always eight bytes.  int64  long  int/long[3]  int64  Bignum  long  integer/string[5]  Int64
bool    bool  boolean  bool  bool  TrueClass/FalseClass  bool  boolean  bool
string  A string must always contain UTF-8 encoded or 7-bit ASCII text, and cannot be longer than 232.  string  String  str/unicode[4]  string  String (UTF-8)  string  string  String
bytes  May contain any arbitrary sequence of bytes no longer than 232.  string  ByteString  str  []byte  String (ASCII-8BIT)  ByteString  string

syntax = "proto3";
option java_package = "app.api";

message Menu{
 int32 id = 1;
 string name = 2;
 int32 status = 3;
 int32 parent = 4;
 string link = 5;
}
message MainMenu{
 int32 id = 1;
 string name = 2;
 int32 status = 3;
 int32 parent = 4;
 string link = 5;
 repeated Menu subs = 6;
}

message MenuEntity{
repeated MainMenu menus = 1;
}

 protoc --proto_path=./ --java_out=./ *.proto 

  mutableListOf<MenuOuterClass.MainMenu.Builder>()
        categories.forEach {
            var mainMenu = MenuOuterClass.MainMenu.newBuilder()
            mainMenu.id = it.id
            mainMenu.name = it.name
            mainMenu.status = it.status
            mainMenu.parent = it.parent
            mainMenu.link = it.link
            it.subs.forEach { menu ->
                var subMenu = MenuOuterClass.Menu.newBuilder()
                subMenu.id = menu.id
                if (!menu.name.isNullOrBlank()) {
                    subMenu.name = menu.name
                }
                subMenu.status = menu.status
                subMenu.parent = menu.parent
                if (!menu.link.isNullOrBlank()) {

                    subMenu.link = menu.link
                }
                mainMenu.addSubs(subMenu)
            }
            menus.addMenus(mainMenu)
        }

        response.contentType = "application/x-protobuf"
        menus.build().writeTo(response.outputStream)
        response.flushBuffer()

      val decodeEntity =  MenuOuterClass.MenuEntity.parseFrom(byteString)