protobuf基于java入门

1. 编写protobuf文件——person.proto

package protobuf;
option java_package="com.sean.person";
option java_outer_classname = "PersonEntity";
message Person{
    required int32 id = 1;
    required string name = 2;
    optional string email=3;
    repeated string friends = 4;
}

2.将protobuf文件转换为java代码

1. 下载protoc.exe该工具

2. 将person.proto加入到protoc.exe所在目录

3. 命令行进入protoc.exe所在目录

4. 执行protoc ./person.proto --java_out=./

3.序列化

4.反序列化

public class Test {
    public static void main(String[] args) throws IOException {
        //实例化builder
        PersonEntity.Person.Builder personBuilder = PersonEntity.Person.newBuilder();
        //添加数据
        personBuilder.setId(1).setName("Sean").setEmail("123@qq.com").addFriends("小明").addFriends("小黄");
        //建立实体数据
        PersonEntity.Person msg = personBuilder.build();
        //将数据写入流中
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        msg.writeTo(output);

        byte[] bytes = output.toByteArray();
        System.out.println("person size: "+bytes.length);

        //读取流
        ByteArrayInputStream bis = new ByteArrayInputStream(bytes);
        PersonEntity.Person person = PersonEntity.Person.parseFrom(bis);
        System.out.println("person ID: " + person.getId());
        System.out.println("person name: " + person.getName());
        System.out.println("person email: " + person.getEmail());
        System.out.println("person friends: "+person.getFriendsList());
    }
}