Question

我正在使用Java跟踪Googles有关Protocol Buffers的教程：https://developers.google.com/protocol-buffers/docs/javatutorial

我正在努力研究教程如何写入文件（即获取用户输入）？你写的是什么类型的文件？ a .proto或.txt（或者你想保存你的数据）。

addressbook.proto：

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;
}

我不打算将这个文件粘贴到Stack上，我用protoc编译成java。我用

完成了

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

在终端。

 Generated File Link - http://pastebin.com/1w7ibDru
 I've also downloaded the Protobuf 2.5.0 jar and added it as a library to my project

AddPerson.java：

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();
  }
}

我明显得到错误：

Usage:  AddPerson ADDRESS_BOOK_FILE

我认为AddPerson类在main中接受一个文件（也许是.txt？）并且没有文件，为什么？

// 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.

评论说文件，但我不知道什么类型的文件？

有人可以告诉我我想要实际写入文件的内容。我不太确定要写入哪种类型的文件。

那里没有那么多Protobuf教程：/

请原谅我，如果这个问题很简单，我从未使用过原型缓冲区。

谢谢。

写入Google协议缓冲区中的文件？

0 个答案: