00. 目錄
文章目錄
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- 01. 枚舉消息格式
- 02. 枚舉測試代碼
- 03. 編譯和測試
- 04. 包的消息格式
- 05. 包的測試程式
- 06. 編譯和測試
- 07. 附錄
當需要定義一個消息類型的時候，可能想為一個字段指定某“預定義值序列”中的一個值，這時候可以通過枚舉實作。
syntax = "proto3";//指定版本資訊，不指定會報錯 message Person //message為關鍵字，作用為定義一種消息類型 { string name = 1; //姓名 int32 id = 2; //id string email = 3; //郵件 enum PhoneType //枚舉消息類型 { MOBILE = 0; //proto3版本中，首成員必須為0，成員不應有相同的值 HOME = 1; WORK = 2; } message PhoneNumber { string number = 1; PhoneType type = 2; } repeated PhoneNumber phones = 4; //phones為數組 } message AddressBook { repeated Person people = 1; } 生成對應檔案
deng@itcast:/mnt/hgfs/LinuxHome/day03$ protoc addressbook.proto --cpp_out=./ deng@itcast:/mnt/hgfs/LinuxHome/day03$ #include "addressbook.pb.h" #include <iostream> #include <fstream> using namespace std; void set_addressbook() { AddressBook obj; Person *p1 = obj.add_people(); //新增加一個Person p1->set_name("tom"); p1->set_id(1); p1->set_email("[email protected]"); Person::PhoneNumber *phone1 = p1->add_phones(); //增加一個phone phone1->set_number("110"); phone1->set_type(Person::MOBILE); Person::PhoneNumber *phone2 = p1->add_phones(); //增加一個phone phone2->set_number("120"); phone2->set_type(Person::HOME); fstream output("pb.itcast", ios::out | ios::trunc | ios::binary); bool flag = obj.SerializeToOstream(&output);//序列化 if (!flag) { cerr << "Failed to write file." << endl; return; } output.close();//關閉檔案 } void get_addressbook() { AddressBook obj; fstream input("./pb.itcast", ios::in | ios::binary); obj.ParseFromIstream(&input); //反序列化 input.close(); //關閉檔案 for (int i = 0; i < obj.people_size(); i++) { const Person& person = obj.people(i);//取第i個people cout << "第" << i + 1 << "個資訊\n"; cout << "name = " << person.name() << endl; cout << "id = " << person.id() << endl; cout << "email = " << person.email() << endl; for (int j = 0; j < person.phones_size(); j++) { const Person::PhoneNumber& phone_number = person.phones(j); switch (phone_number.type()) { case Person::MOBILE: cout << " Mobile phone #: "; break; case Person::HOME: cout << " Home phone #: "; break; case Person::WORK: cout << " Work phone #: "; break; } cout << phone_number.number() << endl; } cout << endl; } } int main() { // Verify that the version of the library that we linked against is // compatible with the version of the headers we compiled against. GOOGLE_PROTOBUF_VERIFY_VERSION; set_addressbook(); //序列化 get_addressbook(); //反序列化 // Optional: Delete all global objects allocated by libprotobuf. google::protobuf::ShutdownProtobufLibrary(); return 0; } 編譯和測試結果
deng@itcast:/mnt/hgfs/LinuxHome/day03$ g++ test.cpp addressbook.pb.cc `pkg-config --libs --cflags protobuf` deng@itcast:/mnt/hgfs/LinuxHome/day03$ ./a.out 第1個資訊 name = tom id = 1 email = [email protected] Mobile phone #: 110 Home phone #: 120 deng@itcast:/mnt/hgfs/LinuxHome/day03$ 
.proto檔案新增一個可選的package聲明符，用來防止不同的消息類型有命名沖突。包的聲明符會根據使用語言的不同影響生成的代碼。對于C++，産生的類會被包裝在C++的命名空間中。
syntax = "proto3";//指定版本資訊，不指定會報錯 package tutorial; //package聲明符 message Person //message為關鍵字，作用為定義一種消息類型 { string name = 1; //姓名 int32 id = 2; //id string email = 3; //郵件 enum PhoneType //枚舉消息類型 { MOBILE = 0; //proto3版本中，首成員必須為0，成員不應有相同的值 HOME = 1; WORK = 2; } message PhoneNumber { string number = 1; PhoneType type = 2; } repeated PhoneNumber phones = 4; //phones為數組 } message AddressBook { repeated Person people = 1; } #include "addressbook.pb.h" #include <iostream> #include <fstream> using namespace std; void set_addressbook() { tutorial::AddressBook obj; tutorial::Person *p1 = obj.add_people(); //新增加一個Person p1->set_name("tom"); p1->set_id(1); p1->set_email("[email protected]"); tutorial::Person::PhoneNumber *phone1 = p1->add_phones(); //增加一個phone phone1->set_number("110"); phone1->set_type(tutorial::Person::MOBILE); tutorial::Person::PhoneNumber *phone2 = p1->add_phones(); //增加一個phone phone2->set_number("120"); phone2->set_type(tutorial::Person::HOME); fstream output("pb.itcast", ios::out | ios::trunc | ios::binary); bool flag = obj.SerializeToOstream(&output);//序列化 if (!flag) { cerr << "Failed to write file." << endl; return; } output.close();//關閉檔案 } void get_addressbook() { tutorial::AddressBook obj; fstream input("./pb.itcast", ios::in | ios::binary); obj.ParseFromIstream(&input); //反序列化 input.close(); //關閉檔案 for (int i = 0; i < obj.people_size(); i++) { const tutorial::Person& person = obj.people(i);//取第i個people cout << "第" << i + 1 << "個資訊\n"; cout << "name = " << person.name() << endl; cout << "id = " << person.id() << endl; cout << "email = " << person.email() << endl; for (int j = 0; j < person.phones_size(); j++) { const tutorial::Person::PhoneNumber& phone_number = person.phones(j); switch (phone_number.type()) { case tutorial::Person::MOBILE: cout << " Mobile phone #: "; break; case tutorial::Person::HOME: cout << " Home phone #: "; break; case tutorial::Person::WORK: cout << " Work phone #: "; break; } cout << phone_number.number() << endl; } cout << endl; } } int main() { // Verify that the version of the library that we linked against is // compatible with the version of the headers we compiled against. GOOGLE_PROTOBUF_VERIFY_VERSION; set_addressbook(); //序列化 get_addressbook(); //反序列化 // Optional: Delete all global objects allocated by libprotobuf. google::protobuf::ShutdownProtobufLibrary(); return 0; } 編譯和測試
deng@itcast:/mnt/hgfs/LinuxHome/day03$ g++ test.cpp addressbook.pb.cc `pkg-config --libs --cflags protobuf` deng@itcast:/mnt/hgfs/LinuxHome/day03$ ./a.out 第1個資訊 name = tom id = 1 email = [email protected] Mobile phone #: 110 Home phone #: 120 deng@itcast:/mnt/hgfs/LinuxHome/day03$ 