Serializing and Sending a Protocol Buffers Message

问题

I have written this protobuf message in c#

C# client:

    public AddressBook InitializeAdressBook() { 

        Person newContact = new Person();
        AddressBook addressBookBuilder = new  AddressBook();
        Person john = new Person();
        john.id=1234;
        john.name="John Doe";
        john.email="jdoe@example.com";
        Person.PhoneNumber nr = new Person.PhoneNumber();
        nr.number="5554321";
        john.phone.Add(nr);
        addressBookBuilder.person.Add(john);
        TextBox.Text += ("Client: Initialisiert? " + addressBookBuilder.ToString()) + "\t" + "\n";
        TextBox.Text += " Erster Person " + addressBookBuilder.person.First().name + "\t" + "\n";

        return addressBookBuilder;
    }

Problem

I am trying to send a protobuf message from a c# client to this java server...

Java server

public ControllerThread(Socket s){
this.s = s; 
try {
        AddressBook adb = AddressBook.parseFrom(s.getInputStream());
        System.out.println("Server: Addressbook:" + adb.getPersonCount());

    } catch (IOException e) { 
        System.out.println("Server: BufferedReader oder PrintWriter von ThermoClient konnte nicht erstellt werden");
        e.printStackTrace(); } 
    }

}

Question:

I should serialize this message to a byte array, so that i can send it to the java server... Unfortunately the method ProtoBuf.Serializer.Serialize dont return a byte array back. So how can i serialize it as a byte array and send it to my Java Server? Any help appreciated thanks!

回答1:

protobuf-net (aka ProtoBuf.Serializer.Serialize) writes to streams. If you have the socket available as a NetworkStream, you can just write directly to that. If you really want a byte[], then use MemoryStream:

byte[] data;
using(var ms = new MemoryStream()) {
     Serializer.Serialize(ms, obj);
     data = ms.ToArray();
}

回答2:

First you had better double check the protocol of the Java server. As described here protobuf is not self-delimiting. This means if you have a TCP connection and are sending multiple protobuf messages, there must be some other underlying protocol to take care of framing - determining where one message ends and another begins.

Let's ignore that problem for now. The actual code to serialize the message depends on which C#/protobuf library you are using. If you are using Jon Skeet's protobuf-csharp-port you might serialize it this way:

AddressBook book = InitializeAddressBook();
byte[] bookBytes = book.ToByteArray();

bookBytes is the address book, serialized to a byte array. Then use whatever socket library you want (for example TcpClient) to send the data (bookBytes) to the Java server.

I'm not convinced this will work because I think there are details about the Java server that you are not telling us.

来源：https://stackoverflow.com/questions/13165690/serializing-and-sending-a-protocol-buffers-message

标签

serialization

network-programming

protocol-buffers

protobuf-net