Protocol Buffer Java实例

大家要先下载protobuffer，在这里：

https://code.google.com/p/protobuf/downloads/list

注意，需要下载两个，一个是complier，另外一个是source code (我下载的是2.5的版本);

讲complier对应的 protoc.exe 拷贝至 source code 对应的./protobuf-2.5.0/src目录下（mvn 编译需要）;

cd 到 ./protobuf-2.5.0/java 目录， 执行 mvn clean package 命令打包；

到target目录获取生成的protobuf-java-2.5.0.jar包（Java代码对protobuf依赖的jar包）；

person.proto文件

package com.shine.pb;
option java_package = "com.shine.pb.person";
option java_outer_classname = "MyPerson";

message Person {
    required int32 id = 1;
    required string name = 2;
    optional string email = 3;

    enum PhoneType {
        MOBILE = 0;
        FIXED = 1;
    }

    message PhoneInfo {
        required string number = 1;
        required PhoneType type = 2 [default=MOBILE];
    }

    optional PhoneInfo phone = 4;
}

到protoc.exe所在目录，执行 protoc --java_out=./output/java ./messages/MyMessage.proto

可生成proto文件对应的Java类；

copy到自己eclipse对应src后；写main方法测试，代码如下：

package com.shine.pb.person;

import com.google.protobuf.InvalidProtocolBufferException;
import com.shine.pb.person.MyPerson.Person.PhoneType;

public class Test {

    public static void main(String[] args) throws InvalidProtocolBufferException {
        MyPerson.Person.Builder  builder = MyPerson.Person.newBuilder();
        builder.setId(1);
        builder.setName("shine");
        builder.setEmail("chenguodong@baidu.com");
        MyPerson.Person.PhoneInfo.Builder phoneInfoBuilder = MyPerson.Person.PhoneInfo.newBuilder();
        phoneInfoBuilder.setNumber("13899999999");
        phoneInfoBuilder.setType(PhoneType.MOBILE);
        builder.setPhone(phoneInfoBuilder.build());

        MyPerson.Person shine = builder.build();

        System.out.println(shine.getSerializedSize());
        System.out.println(shine.getEmail());
        System.out.println(shine.getName());
        System.out.println(shine.getPhone().getNumber());

        System.out.println("=============================================");

        byte[] data = shine.toByteArray();
        builder = MyPerson.Person.newBuilder();
        MyPerson.Person person = MyPerson.Person.parseFrom(data);
        System.out.println(person.getSerializedSize());
        System.out.println(person.getEmail());
        System.out.println(person.getName());
        System.out.println(person.getPhone().getNumber());
    }

}