ProtoBuffer

序列化数据的要求

1.        效率  时间空间
2.        多语言相互操作
3.        使用方便

ProtoBuffer 使用：

1. Designing objects

   Person:
   Id
   Name
   Age
   Email
   Phone(s)
   

   　　

2. Describing objects

   Person:
   required int32 id
   required string name
   optional string email
   repeated string phone

3. Compiling the description

   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 --java_out=$DST_DIR addressbook.proto

4. Obtaining the generated source-code

5. Importing objects into your project

6. Instantiating objects

   Person  john = Person.newBuilder()
   .setId(12345)
   .setName
   .setEmail
   .addPhone(Person.PhoneNumber.newBuilder()
   .setNumber("+351 999 999 999")
   .setType(Person.PhoneType.HOME)
   .build())
   .build();

7. Using objects

   // Writing data to a file
   FileOutputStream  aOutput  = new FileOutputStream（"theFilename")
   Person  aPerson = Person.newBuilder.set()....   //instance  a Person
   aPerson.writeTo(aOutput);
   aOutput.close();
   
   // Reading data from a file
   Person  aPerson = Person.parseFrom(new FileInputStream("theFilename"))
   // Do something with the received Person

ProtoBuffer 重点在

1. Efficiency (space and time)   效率 （空间和时间）

2. Language interoperability     多语言互操作性
3. Usability                             方便使用

其它解决方案

1. Avro (http://avro.apache.org/)

2. Thrift (http://thrift.apache.org/)
3. Kryo (https://github.com/EsotericSoftware/kryo)