用Maven实现一个protobuf的Java例子

2022-12-03 08:22:19

注：试验环境在Mac Idea环境下

1. 介绍Protocol Buffers

Protocal Buffers(简称protobuf)是谷歌的一项技术，用于结构化的数据序列化、反序列化，常用于RPC 系统（Remote Procedure Call Protocol System）和持续数据存储系统。

其类似于XML生成和解析，但protobuf的效率高于XML，不过protobuf生成的是字节码，可读性比XML差，类似的还有json、Java的Serializable等。

很适合做数据存储或 RPC 数据交换格式。可用于通讯协议、数据存储等领域的语言无关、平台无关、可扩展的序列化结构数据格式。

2. Idea 安装protobuf插件

安装插件protobuf Support，之后重启

3. 配置依赖

pom.xml添加

<dependencies>

        <dependency>

            <groupId>com.google.protobuf</groupId>

            <artifactId>protobuf-java</artifactId>

            <version>3.4.0</version>

        </dependency>

</dependencies>

<build>

        <extensions>

            <extension>

                <groupId>kr.motd.maven</groupId>

                <artifactId>os-maven-plugin</artifactId>

                <version>1.4.1.Final</version>

            </extension>

        </extensions>

        <plugins>

            <plugin>

                <groupId>org.xolstice.maven.plugins</groupId>

                <artifactId>protobuf-maven-plugin</artifactId>

                <version>0.5.0</version>

                <configuration>

                    <protocArtifact>

                        com.google.protobuf:protoc:3.1.0:exe:${os.detected.classifier}

                    </protocArtifact>

                    <pluginId>grpc-java</pluginId>

                </configuration>

                <executions>

                    <execution>

                        <goals>

                            <goal>compile</goal>

                            <goal>compile-custom</goal>

                        </goals>

                    </execution>

                </executions>

            </plugin>

        </plugins>
</build>

4. 书写proto文件

syntax = "proto3";

option java_package = "com.jihite";

option java_outer_classname = "PersonModel";

message Person {

     int32 id = 1;

     string name = 2;

     string email = 3;

}

5. 转化成Java文件

6. 测试

把生成的类考的代码路径下，用下面测试用例测试

package com.jihite;

import com.google.protobuf.InvalidProtocolBufferException;

import org.junit.Test;

public class protobufTest {

    @Test

    public void testN() throws InvalidProtocolBufferException {

        PersonModel.Person.Builder builder = PersonModel.Person.newBuilder();

        builder.setId(1);

        builder.setName("jihite");

        builder.setEmail("jihite@jihite.com");

        PersonModel.Person person = builder.build();

        System.out.println("before:" + person);

        System.out.println("===Person Byte:");

        for (byte b : person.toByteArray()) {

            System.out.print(b);

        }

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

        byte[] byteArray = person.toByteArray();

        PersonModel.Person p2 = PersonModel.Person.parseFrom(byteArray);

        System.out.println("after id:" + p2.getId());

        System.out.println("after name:" + p2.getName());

        System.out.println("after email:" + p2.getEmail());

    }

}

结果

before:id: 1

name: "jihite"

email: "jihite@jihite.com"

===Person Byte:

811861061051041051161012617106105104105116101641061051041051161014699111109================

after id:1

after name:jihite

after email:jihite@jihite.com

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