protobuf for java

package tutorial;

option java_package = "com.example.tutorial";

option java_outer_classname = "AddressBookProtos";

message Person {

  required string name = 1;

  required int32 id = 2;

  optional string email = 3;

  enum PhoneType {

    MOBILE = 0;

    HOME = 1;

    WORK = 2;

  }

  message PhoneNumber {

    required string number = 1;

    optional PhoneType type = 2 [default = HOME];

  }

  repeated PhoneNumber phone = 4;

}

message AddressBook {

  repeated Person person = 1;

}

protoc -I=$SRC_DIR --java_out=$DST_DIR $SRC_DIR/addressbook.proto

// required string name = 1; public boolean hasName(); public java.lang.String getName(); public Builder setName(String value); public Builder clearName();
// required int32 id = 2; public boolean hasId(); public int getId(); public Builder setId(int value); public Builder clearId();
// optional string email = 3; public boolean hasEmail(); public String getEmail(); public Builder setEmail(String value); public Builder clearEmail();
// repeated .tutorial.Person.PhoneNumber phone = 4; public List<PhoneNumber> getPhoneList(); public int getPhoneCount(); public PhoneNumber getPhone(int index); public Builder setPhone(int index, PhoneNumber value); public Builder addPhone(PhoneNumber value); public Builder addAllPhone(Iterable<PhoneNumber> value); public Builder clearPhone();

public static enum PhoneType {   MOBILE(0, 0),   HOME(1, 1),   WORK(2, 2),   ;   ... }

Person john =   Person.newBuilder()     .setId(1234)     .setName("John Doe")     .setEmail("jdoe@example.com")     .addPhone(       Person.PhoneNumber.newBuilder()         .setNumber("555-4321")         .setType(Person.PhoneType.HOME))     .build();

import com.example.tutorial.AddressBookProtos.AddressBook; import com.example.tutorial.AddressBookProtos.Person; import java.io.BufferedReader; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.InputStreamReader; import java.io.IOException; import java.io.PrintStream;
class AddPerson {   // This function fills in a Person message based on user input.   static Person PromptForAddress(BufferedReader stdin,                                  PrintStream stdout) throws IOException {     Person.Builder person = Person.newBuilder();
    stdout.print("Enter person ID: ");     person.setId(Integer.valueOf(stdin.readLine()));
    stdout.print("Enter name: ");     person.setName(stdin.readLine());
    stdout.print("Enter email address (blank for none): ");     String email = stdin.readLine();     if (email.length() > 0) {       person.setEmail(email);     }
    while (true) {       stdout.print("Enter a phone number (or leave blank to finish): ");       String number = stdin.readLine();       if (number.length() == 0) {         break;       }
      Person.PhoneNumber.Builder phoneNumber =         Person.PhoneNumber.newBuilder().setNumber(number);
      stdout.print("Is this a mobile, home, or work phone? ");       String type = stdin.readLine();       if (type.equals("mobile")) {         phoneNumber.setType(Person.PhoneType.MOBILE);       } else if (type.equals("home")) {         phoneNumber.setType(Person.PhoneType.HOME);       } else if (type.equals("work")) {         phoneNumber.setType(Person.PhoneType.WORK);       } else {         stdout.println("Unknown phone type.  Using default.");       }
      person.addPhone(phoneNumber);     }
    return person.build();   }
  // Main function:  Reads the entire address book from a file,   //   adds one person based on user input, then writes it back out to the same   //   file.   public static void main(String[] args) throws Exception {     if (args.length != 1) {       System.err.println("Usage:  AddPerson ADDRESS_BOOK_FILE");       System.exit(-1);     }
    AddressBook.Builder addressBook = AddressBook.newBuilder();
    // Read the existing address book.     try {       addressBook.mergeFrom(new FileInputStream(args[0]));     } catch (FileNotFoundException e) {       System.out.println(args[0] + ": File not found.  Creating a new file.");     }
    // Add an address.     addressBook.addPerson(       PromptForAddress(new BufferedReader(new InputStreamReader(System.in)),                        System.out));
    // Write the new address book back to disk.     FileOutputStream output = new FileOutputStream(args[0]);     addressBook.build().writeTo(output);     output.close();   } }

import com.example.tutorial.AddressBookProtos.AddressBook; import com.example.tutorial.AddressBookProtos.Person; import java.io.FileInputStream; import java.io.IOException; import java.io.PrintStream;
class ListPeople {   // Iterates though all people in the AddressBook and prints info about them.   static void Print(AddressBook addressBook) {     for (Person person: addressBook.getPersonList()) {       System.out.println("Person ID: " + person.getId());       System.out.println("  Name: " + person.getName());       if (person.hasEmail()) {         System.out.println("  E-mail address: " + person.getEmail());       }
      for (Person.PhoneNumber phoneNumber : person.getPhoneList()) {         switch (phoneNumber.getType()) {           case MOBILE:             System.out.print("  Mobile phone #: ");             break;           case HOME:             System.out.print("  Home phone #: ");             break;           case WORK:             System.out.print("  Work phone #: ");             break;         }         System.out.println(phoneNumber.getNumber());       }     }   }
  // Main function:  Reads the entire address book from a file and prints all   //   the information inside.   public static void main(String[] args) throws Exception {     if (args.length != 1) {       System.err.println("Usage:  ListPeople ADDRESS_BOOK_FILE");       System.exit(-1);     }
    // Read the existing address book.     AddressBook addressBook =       AddressBook.parseFrom(new FileInputStream(args[0]));
    Print(addressBook);   } }