Android 中使用Protocol Buffer

宝宝其实是根据一老外的文章学习的，原文：
https://medium.com/@elye.project/simple-android-protobuf-tutorial-with-actual-code-bfb581299f47
本篇文章主要介绍Android中配置Gradle Protocol Buffer，及一个简单的使用demo，下篇文件讲解API


在其中一个项目中遇到SharedPerfernce 插入数据时报ANR，弄的我是有口难言，谁叫我滥用SP呢？
无意中在一本讲python的书中讲到protobuf，研究之，兴奋之，撸之！其实我的原本的想法是把protobuf
封装成SharedPerfernce这样的方式既能快速使用，又能提升性能。于是protobuf处女作


宝宝在marven上面找到最新的插件，可以看出，上面已经开始落满了灰。但是有名言不是说了么，
酒香不怕巷子深，猪肉不怕年头陈。

截至2018/05/20
在mvnrepository 上面找到最新的 protobuf-gradle-plugin 0.8.5下面是官网
http://mvnrepository.com/artifact/com.google.protobuf/protobuf-gradle-plugin/0.8.5
Protocol Buffers [Lite] 最新的3.0.1
http://mvnrepository.com/artifact/com.google.protobuf/protobuf-lite
protoc 最新的为 3.5.1
http://mvnrepository.com/artifact/com.google.protobuf/protoc
:protoc-gen-javalite 最新的为 3.0.0

http://mvnrepository.com/artifact/com.google.protobuf/protoc-gen-javalite

AndroidStudio  Project build.gradle

buildscript {
    repositories {
        jcenter()
        google()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.0.1'
        classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.5'
    }
}
allprojects {
    repositories {
        jcenter()
        google()
    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

application build.gradle

apply plugin: 'com.android.application'
apply plugin: 'com.google.protobuf'

android {
    compileSdkVersion 25
    buildToolsVersion '26.0.2'
    defaultConfig {
        applicationId "com.example.rxjavademo"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    repositories {
        flatDir {
            dirs 'libs'
        }
    }
}
protobuf {
    protoc {
        artifact = 'com.google.protobuf:protoc:3.5.1-1'

    }
    plugins {
        javalite {
            artifact = 'com.google.protobuf:protoc-gen-javalite:3.0.0'
        }
    }
    generateProtoTasks {
        all().each { task ->
            task.builtins {
                remove java
            }
            task.plugins {
                javalite {}
            }
        }
    }
}
dependencies {
    compile fileTree(include: ['*.jar'], dir: 'libs')
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'io.reactivex.rxjava2:rxjava:2.0.1'
    compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
    implementation 'com.google.protobuf:protobuf-lite:3.0.1'
    implementation 'com.squareup.okhttp3:okhttp:3.8.0'
}

在main 文件夹下创建proto文件夹，编写.proto文件

dataformat.proto文件

syntax = "proto3";
package tutorial;

message Person {
    string name = 1;
    int32 id = 2;
    string email = 3;
    string phone = 4;
        map<string, string> pairs = 5;
}

编译项目，会在build文件夹下proto文件夹内生成对应的java文件

下面就可以愉快的玩耍了

Activity中代码，里面是使用okhttp请求网络，接收到protobuf的byte字节转成java对象

package com.example.rxjavademo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import io.reactivex.Observable;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.functions.Consumer;
import io.reactivex.functions.Function;
import io.reactivex.schedulers.Schedulers;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.ResponseBody;
import tutorial.Dataformat.Person;

public class ProtocalActivity extends AppCompatActivity {
    private OkHttpClient okHttpClient = new OkHttpClient();

    private Observable observable = Observable.just("http://elyeproject.x10host.com/experiment/protobuf")
            .map(new Function<String, Person>() {
                @Override
                public Person apply(String url) throws Exception {
                    Request request = new Request.Builder().url(url).build();
                    okhttp3.Call call = okHttpClient.newCall(request);
                    Response response = call.execute();

                    if (response.isSuccessful()) {
                        ResponseBody responseBody = response.body();
                        if (responseBody != null) {
                            return Person.parseFrom(responseBody.byteStream());
                        }
                    }

                    return null;
                }
            }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread());

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_protocal);
        observable.subscribe(new Consumer() {
            @Override
            public void accept(Object object) throws Exception {
                showResult((Person) object);
            }
        });
    }

    private void showResult(Person result) {

        TextView textView = (TextView) findViewById(R.id.txt_main);
        textView.setText(result.toString());
//        result.writeTo();
//         Person.Builder builder = Person.newBuilder();
//         builder.putPairs();
    }
}

效果图