Protocol Buffers(即protobuf)是Google开源的序列化库，是一种轻便高效的结构化数据存储格式，可以用于结构化数据序列化/反序列化。它很适合做数据存储或RPC的数据交换格式，常用作通信协议、数据存储等领域。 相比于常见的XML格式，ProtocolBuffers官方网站这样描述它的优点：
- 平台无关、语言无关；
- 高性能；
- 体积小；
- 使用简单；
- 兼容性好。
现在尝试一下Protocol Buffers支持的各种数据类型。
test.proto
package com.yqu.proto;
option java_package = "com.yqu.proto";
option java_outer_classname="TestProtos";
message Test {
required double doubleVar = 1;
required float floatVar = 2;
required int32 int32Var = 3;
required int64 int64Var = 4;
required uint32 uint32Var = 5;
required uint64 uint64Var = 6;
required sint32 sint32Var = 7;
required sint64 sint64Var = 8;
required fixed32 fixed32Var = 9;
required fixed64 fixed64Var = 10;
required sfixed32 sfixed32Var = 11;
required sfixed64 sfixed64Var = 12;
required bool booleanVar = 13;
required string stringVar = 14;
required bytes bytesVar = 15;
enum Suit {
SPADES = 0;
HEARTS = 1;
DIAMONDS = 2;
CLUBS = 3;
}
required Suit enumVar = 16 [default = HEARTS];
repeated int32 int32ArrayVar = 17;
repeated uint32 uint32ArrayVar = 18 [packed=true];
repeated string stringArrayVar = 19;
message MsgVar {
required string url = 1;
optional string title = 2;
}
repeated MsgVar msgVar = 20;
}
使用Google提供的Protocol Buffers编译器生成Java语言：
protoc -java_ out=. person. proto
TestProtos.java
