(三)安卓框架搭建之MVP+Retrofit+RxJava基礎

上一篇,算是完成了準備工作,那么這篇就來說說MVP和RxJava的封裝了。首先看看接口返回數據的格式:

{
"code" : 1,
"message" : "請求成功!" ,
"data" : {
    "name": "張三",
    "age": 3
  }
}

code、message、data標準的三大門神。一般是以這種格式返回數據。數據格式的統一利于封裝,以此數據格式為準的實體基類如下
在dataframework內新建包model和BaseResponseBean類。

Paste_Image.png
package com.example.burro.demo.dataframework.model;

/**基類 泛型T為實體數據
 * Created by ex.zhong on 2017/9/23.
 */
public class BaseResponseBean<T> {
    private int code;
    private String message;
    private T data;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }

由于后面的demo用到豆瓣的API,很遺憾它的格式并非上述標準的格式。在項目中返回的數據用了繼承父類方式,而非上面的泛型方式,為了區分。新的父類名字我改為BaseResultBean,上面的標準格式基類我仍舊保存到demo中,如果更換的話,那也是分分鐘的事情。后面案例和講解也將使用BaseResultBean,其內容如下:

package com.example.burro.demo.dataframework.model;

/**返回數據父類。子類可繼承
 * Created by ex.zhong on 2017/9/23.
 */
public class BaseResultBean {
    protected int code;
    protected String msg;
    public BaseResultBean() {
    }
    public BaseResultBean(int code, String msg) {
        this.code = code;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

當然,項目中要根據實際數據為準來調整調整字段、結構等。沒有必要過于糾結數據格式問題,換湯不換藥,道理是一樣的。

下面進行MVP相關內容的講解!

依賴包引入:

項目的build.gradle增加如下appframework

        /*rx-android-java*/
        rxjava                : 'io.reactivex:rxjava:1.1.0',
        rxandroid             : 'io.reactivex:rxandroid:1.1.0',
        retrofit              : 'com.squareup.retrofit2:retrofit:2.0.2',
        converter_gson        : 'com.squareup.retrofit2:converter-gson:2.0.2',
        adapter_rxjava        : 'com.squareup.retrofit2:adapter-rxjava:2.0.2',
        //compile 'com.google.code.gson:gson:2.6.2'
        logging_interceptor   : 'com.squareup.okhttp3:logging-interceptor:3.3.0',
        spots_dialog          : 'com.github.d-max:spots-dialog:0.7@aar',

dataframework的build.gradle增加如下

    compile deps.rxjava
    compile deps.rxandroid
    compile deps.retrofit
    compile deps.converter_gson
    compile deps.adapter_rxjava
    compile deps.logging_interceptor
    compile deps.spots_dialog
    compile deps.annotation

BaseView

Paste_Image.png

寫之前需要在appframework下新建包mvp,mvp下新建三個包contract,presenter,view
在view下新建接口BaseView,Baseview接口內的方法是頁面內【Activity或者Fragment】需要執行的通用方法。這里先定義一個 showError(BaseResultBean resultBean); 返回正確情況有很多種,在實現類中增加,若錯誤,我們要統一處理。所以showError(BaseResultBean resultBean)方法是全局共有的。

package com.example.burro.demo.appframework.mvp.view;

import com.example.burro.demo.dataframework.model.BaseResultBean;

/**View接口
 * Created by ex.zhong on 2017/9/23.
 */
public interface BaseView {
    void showError(BaseResultBean  resultBean);
}

BasePresenter

Presenter和View創建類似,
在presenter下新建IPresenter,IPresenter attachView(T view); void detachView();兩個方法是全局共有的

package com.example.burro.demo.appframework.mvp.presenter;

import com.example.burro.demo.appframework.mvp.view.BaseView;

/**Presenter接口
 * 注:在創建presenter時綁定,在頁面destroy()時解綁。
 * Created by ex.zhong on 2017/9/23.
 */
public interface IPresenter<T extends BaseView> {
    void attachView(T view);
    void detachView();
}

因為幾乎每個Presenter實現類里都要處理綁定和解綁事件,所以我們要把這個處理過程提取出來,此處寫一個基類BasePresenter統一管理,在presenter下新建BasePresenter實現IPresenter

package com.example.burro.demo.appframework.mvp.presenter;

import com.example.burro.demo.appframework.mvp.view.BaseView;

/**
 * Presenter基類。目的是統一處理綁定和解綁
 * Created by ex.zhong on 2017/9/23.
 */
public class BasePresenter<T extends BaseView> implements IPresenter<T> {

    protected T mView;

    @Override
    public void attachView(T mView) {
        mView = mView;
    }

    @Override
    public void detachView() {
        mView = null;
    }

  //   public boolean isViewAttached() {
  //      return mView != null;
  //    }

  //    public void checkViewAttached() {
  //        if (!isViewAttached()) throw new  
  // MvpViewNotAttachedException();
  //  }
![Uploading 04_766476.png . . .]

  //   public static class  //MvpViewNotAttachedException extends //RuntimeException {
  //        public MvpViewNotAttachedException() {
  //           super("Please call   //Presenter.attachView(MvpView) before" +
  //                    " requesting data to the   //Presenter");
  //        }
  //    }
}

【備注:這里的checkViewAttached(),在rxJava未引入之前使用。目的是判斷頁面是否還存在,若不存在則不執行。rxJava中對此作了處理。只需調用解綁方法即可。在此處稍作提及,后面我會直接刪掉此內容】

稍后會寫一個測試類TestActivty結合豆瓣的API。來詳解mvp的使用。在此之前先來封裝一下BaseActivity,因為一般都是在BaseActivity中進行Presenter和View的初始化綁定

BaseActivity

在appframework新建ui包,包內新建BaseActivity抽象類

類中都是基本的要素,且注釋較為詳細,容易理解。其中有個別方法是為了和后面內容對接,直接貼代碼:

package com.example.burro.demo.appframework.ui;

import android.app.Activity;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.view.View;

import com.example.burro.demo.appframework.BaseApplication;
import com.example.burro.demo.appframework.mvp.presenter.BasePresenter;
import com.example.burro.demo.appframework.mvp.view.BaseView;

import butterknife.ButterKnife;
import butterknife.Unbinder;

/**
 * BaseActivity Activity基類
 * butterKnife的綁定 初始方法的設定 presentet和view的綁定
 * Created by ex.zhong on 2017/9/23.
 */
public abstract class BaseActivity<T extends BasePresenter> extends AppCompatActivity implements BaseView,Toolbar.OnMenuItemClickListener {
    protected T mPresenter;
    protected Activity mContext;
    private Unbinder mUnbinder;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(initLayoutInflater());
        mUnbinder = ButterKnife.bind(this);
        mContext = this;
        createPresenter();
        if (mPresenter != null) mPresenter.attachView(this);
        BaseApplication.getInstance().addActivity(this);
        initParams();
        initViews();
    }
    protected abstract int initLayoutInflater(); //初始化布局

    protected abstract void initParams(); //初始化參數

    protected abstract void initViews();  //初始化控件

    protected abstract void createPresenter(); //創建presenter

    /**
     * @param toolbar toolbar 控件
     * @param title   標題
     */
    protected void setToolBar(Toolbar toolbar, String title) {
        if (toolbar != null) {
            if (title != null) toolbar.setTitle(title);
            setSupportActionBar(toolbar);
            toolbar.setOnMenuItemClickListener(this);
            getSupportActionBar().setDisplayHomeAsUpEnabled(true);
            getSupportActionBar().setDisplayShowHomeEnabled(true);
            toolbar.setNavigationOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    onBackPressed();
                }
            });
        }
    }
    //toolbar右側menu點擊事件
    @Override
    public boolean onMenuItemClick(MenuItem item) {
        return false;
    }
      //統一處理錯誤信息
    public void handleError(BaseResultBean errResult) {
        if (errResult == null) return;
        if (this == null) return;
        //可以分門別類的處理 錯誤消息,如session過期,跳轉到登錄頁面。其他情況提示即可
        ToastUtils.showToast(mContext, errResult.getMsg());
    }
    
    @Override
    protected void onDestroy() {
        if (mPresenter != null) mPresenter.detachView();
        if (mUnbinder != null) mUnbinder.unbind();
        super.onDestroy();
    }
}

在biz新建測試類

新建內容如下 biz/test/view/TestActivity、biz/test/TestContract、biz/test/TestPresenterImpl

1.包內新建TestActivity繼承BaseActivity.TestActivity

package com.example.burro.demo.appbiz.test.view;

import com.example.burro.demo.appbiz.R;
import com.example.burro.demo.appbiz.R2;
import com.example.burro.demo.appbiz.test.TestContract;
import com.example.burro.demo.appbiz.test.TestPresenterImpl;
import com.example.burro.demo.appframework.ui.BaseActivity;
import com.example.burro.demo.appframework.util.LogUtils;
import com.example.burro.demo.databiz.model.test.MovieListBean;
import com.example.burro.demo.dataframework.model.BaseResultBean;

import butterknife.OnClick;

/**測試頁面
 * Created by ex.zhong on 2017/9/23.
 */
public class TestActivity extends BaseActivity<TestPresenterImpl> implements TestContract.View{
    @Override
    protected int initLayoutInflater() {
        return R.layout.activity_test;
    }
    @Override
    protected void initParams() {
    }
    @Override
    protected void initViews() {
    }

    @Override
    protected void createPresenter() {
        mPresenter = new TestPresenterImpl();
    }

    @Override
    public void showError(BaseResultBean resultBean) {
         //錯誤處理
        handleError(resultBean);
    }

    @Override
    public void setMovieListData(MovieListBean bean) {
        LogUtils.i("TAG",bean==null?"":bean.toString());
    }
    @OnClick(R2.id.btnTest)
    public void getMovieListData(){
        mPresenter.getMovieListData(1,15);
    }
}

這里的showError(),是BasePresenter中的回調方法,用來統一處理錯誤情況,若頁面有RecycalView并正在刷新的情況,也可在此處結束刷新。因為每個頁面都會showError(),所以我們需要在BaseActivity里增加統一處理的方法handleError(resultBean),內容如下:

    //統一處理錯誤信息
    public void handleError(BaseResultBean errResult) {
        if (errResult == null) return;
        if (this == null) return;
        //可以分門別類的處理 錯誤消息,如session過期,跳轉到登錄頁面。其他情況提示即可
        ToastUtils.showToast(mContext, errResult.getMsg());
    }

值得強調的是,增加錯誤結果統一處理很有必要,也很少有人注意這點,我們后面網絡請求錯誤結果的返回也會與此對接。此處默認是給出Toast提示信息,當然還有很多其他操作,正如注釋所說:如果errResult的code是session過期的標識,那么我們給出提示的同時也會跳轉至登錄頁面等等。

2.TestContract:

Contract:d單詞意思為契約、協議。TestContract即協議類,定制mvp各層接口和實現方法。說白了,就是把v層和p層需要實現的方法統一在一塊,方便管理,也起到了解耦作用。

package com.example.burro.demo.appbiz.test;

import com.example.burro.demo.appframework.mvp.presenter.IPresenter;
import com.example.burro.demo.appframework.mvp.view.BaseView;
import com.example.burro.demo.databiz.model.test.MovieListBean;

/**協議類,定制mvp各層接口和實現方法
 * Contract:d單詞意思為契約 協議
 * 接口View內 定義實現view內所需方法
 * 接口Presenter 定義實現presenter內所需的方法
 * Created by ex.zhong on 2017/9/23.
 */
public class TestContract {
    public interface View extends BaseView {
        void setMovieListData(MovieListBean bean);
    }

    public interface Presenter extends IPresenter<View> {
        void getMovieListData(int start,int count);
    }
}

3.TestPresenterImpl:

TestPresenterImpl繼承自BasePresenter,初級版本如下:

package com.example.burro.demo.appbiz.test;

import com.example.burro.demo.appframework.mvp.presenter.BasePresenter;
import com.example.burro.demo.appbiz.test.TestContract.*;
import com.example.burro.demo.appframework.util.LogUtils;
import com.example.burro.demo.appframework.util.StringUtils;
import com.example.burro.demo.databiz.model.test.MovieListBean;
import com.example.burro.demo.databiz.service.ApiService;
import com.example.burro.demo.dataframework.http.HttpConfig;

import java.util.HashMap;

import retrofit2.Retrofit;
import retrofit2.adapter.rxjava.RxJavaCallAdapterFactory;
import retrofit2.converter.gson.GsonConverterFactory;
import rx.Subscriber;
import rx.android.schedulers.AndroidSchedulers;
import rx.schedulers.Schedulers;

/**測試presenter
 * Created by ex.zhong on 2017/9/23.
 */
public class TestPresenterImpl extends BasePresenter<View> implements Presenter {

    @Override
    public void getMovieListData(int start, int count) {
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(HttpConfig.BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .build();
        ApiService movieService = retrofit.create(ApiService.class);
        HashMap<String,String> map=new HashMap<>();
        map.put("start", StringUtils.getString(start));
        map.put("count",StringUtils.getString(count));
        movieService.getMovieListData(map)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new Subscriber<MovieListBean>() {
                    @Override
                    public void onStart() {
                        //請求開始
                        LogUtils.i("TestPresenterImpl","onStart()");
                    }
                    @Override
                    public void onCompleted() {
                       // //請求完成
                        LogUtils.i("TestPresenterImpl","onCompleted()");
                    }
                    @Override
                    public void onError(Throwable e) {
                        // //請求異常
                        LogUtils.i("TestPresenterImpl","onError()");
                    }
                    @Override
                    public void onNext(MovieListBean movieListBean) {
                        // //請求OK,執行
                        LogUtils.i("TestPresenterImpl","onNext()");
                        mView.setMovieListData(movieListBean);
                    }
                });
    }
}

文中用到的豆瓣電影TOP250的URL為:http://api.douban.com/v2/movie/top250?start=1&count=15

其他幾個主要輔助的類或資源分別為如下:

布局文件activity_test.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.burro.demo.appbiz.test.view.TestActivity">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />
    </android.support.design.widget.AppBarLayout>
    <Button
        android:id="@+id/btnTest"
        android:layout_below="@id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="請求數據"
        />

</RelativeLayout>

其中AppTheme.PopupOver,AppTheme.AppBarOverlay等是toolbar相關的樣式資源,請到demo中查看,此處不一一列出

ApiService接口類 databiz/service/ApiService:

package com.example.burro.demo.databiz.service;


import com.example.burro.demo.databiz.model.test.MovieListBean;

import java.util.HashMap;
import java.util.Map;

import retrofit2.http.GET;
import retrofit2.http.Path;
import retrofit2.http.Query;
import retrofit2.http.QueryMap;
import rx.Observable;

/**
 *  存放訪問網絡的方法
 * Created by ex.zhong on 2017/9/24.
 */
public interface ApiService {
    public static final String URL_MOVIELIST="/v2/movie/top250"; //豆瓣電影top250
    @GET(URL_MOVIELIST)
    Observable<MovieListBean> getMovieListData(@QueryMap HashMap<String,String> count);
}

網絡配置類 dataframework/http/HttpConfig :

package com.example.burro.demo.dataframework.http;

/**
 * Created by ex.zhong on 2017/9/24.
 *放置網絡相關配置數據,如IP/端口等
 */
public class HttpConfig {
    public final static String BASE_URL="http://api.douban.com";
}

電影列表實體類 databiz/model/test/MovieListBean :

package com.example.burro.demo.databiz.model.test;

import com.example.burro.demo.dataframework.model.BaseResultBean;

import java.util.List;

/**豆瓣電影列表
 * Created by ex.zhong on 2017/9/24.
 */

public class MovieListBean extends BaseResultBean{

    public List<SubjectsBean> subjects;

    public static class SubjectsBean {
        /**
         * rating : {"max":10,"average":9.6,"stars":"50","min":0}
         * genres : ["犯罪","劇情"]
         * title : 肖申克的救贖
         * casts : [{"alt":"https://movie.douban.com/celebrity/1054521/","avatars":{"small":"https://img3.doubanio.com/img/celebrity/small/17525.jpg","large":"https://img3.doubanio.com/img/celebrity/large/17525.jpg","medium":"https://img3.doubanio.com/img/celebrity/medium/17525.jpg"},"name":"蒂姆·羅賓斯","id":"1054521"},{"alt":"https://movie.douban.com/celebrity/1054534/","avatars":{"small":"https://img3.doubanio.com/img/celebrity/small/34642.jpg","large":"https://img3.doubanio.com/img/celebrity/large/34642.jpg","medium":"https://img3.doubanio.com/img/celebrity/medium/34642.jpg"},"name":"摩根·弗里曼","id":"1054534"},{"alt":"https://movie.douban.com/celebrity/1041179/","avatars":{"small":"https://img1.doubanio.com/img/celebrity/small/5837.jpg","large":"https://img1.doubanio.com/img/celebrity/large/5837.jpg","medium":"https://img1.doubanio.com/img/celebrity/medium/5837.jpg"},"name":"鮑勃·岡頓","id":"1041179"}]
         * collect_count : 1107705
         * original_title : The Shawshank Redemption
         * subtype : movie
         * directors : [{"alt":"https://movie.douban.com/celebrity/1047973/","avatars":{"small":"https://img3.doubanio.com/img/celebrity/small/230.jpg","large":"https://img3.doubanio.com/img/celebrity/large/230.jpg","medium":"https://img3.doubanio.com/img/celebrity/medium/230.jpg"},"name":"弗蘭克·德拉邦特","id":"1047973"}]
         * year : 1994
         * images : {"small":"https://img3.doubanio.com/view/movie_poster_cover/ipst/public/p480747492.webp","large":"https://img3.doubanio.com/view/movie_poster_cover/lpst/public/p480747492.webp","medium":"https://img3.doubanio.com/view/movie_poster_cover/spst/public/p480747492.webp"}
         * alt : https://movie.douban.com/subject/1292052/
         * id : 1292052
         */

        public RatingBean rating;
        public String title;
        public int collect_count;
        public String original_title;
        public String subtype;
        public String year;
        public ImagesBean images;
        public String alt;
        public String id;
        public List<String> genres;
        public List<CastsBean> casts;
        public List<DirectorsBean> directors;

        public static class RatingBean {
            /**
             * max : 10
             * average : 9.6
             * stars : 50
             * min : 0
             */

            public int max;
            public double average;
            public String stars;
            public int min;
        }

        public static class ImagesBean {
            /**
             * small : https://img3.doubanio.com/view/movie_poster_cover/ipst/public/p480747492.webp
             * large : https://img3.doubanio.com/view/movie_poster_cover/lpst/public/p480747492.webp
             * medium : https://img3.doubanio.com/view/movie_poster_cover/spst/public/p480747492.webp
             */

            public String small;
            public String large;
            public String medium;
        }

        public static class CastsBean {
            /**
             * alt : https://movie.douban.com/celebrity/1054521/
             * avatars : {"small":"https://img3.doubanio.com/img/celebrity/small/17525.jpg","large":"https://img3.doubanio.com/img/celebrity/large/17525.jpg","medium":"https://img3.doubanio.com/img/celebrity/medium/17525.jpg"}
             * name : 蒂姆·羅賓斯
             * id : 1054521
             */

            public String alt;
            public AvatarsBean avatars;
            public String name;
            public String id;

            public static class AvatarsBean {
                /**
                 * small : https://img3.doubanio.com/img/celebrity/small/17525.jpg
                 * large : https://img3.doubanio.com/img/celebrity/large/17525.jpg
                 * medium : https://img3.doubanio.com/img/celebrity/medium/17525.jpg
                 */

                public String small;
                public String large;
                public String medium;
            }
        }

        public static class DirectorsBean {
            /**
             * alt : https://movie.douban.com/celebrity/1047973/
             * avatars : {"small":"https://img3.doubanio.com/img/celebrity/small/230.jpg","large":"https://img3.doubanio.com/img/celebrity/large/230.jpg","medium":"https://img3.doubanio.com/img/celebrity/medium/230.jpg"}
             * name : 弗蘭克·德拉邦特
             * id : 1047973
             */

            public String alt;
            public AvatarsBeanX avatars;
            public String name;
            public String id;

            public static class AvatarsBeanX {
                /**
                 * small : https://img3.doubanio.com/img/celebrity/small/230.jpg
                 * large : https://img3.doubanio.com/img/celebrity/large/230.jpg
                 * medium : https://img3.doubanio.com/img/celebrity/medium/230.jpg
                 */

                public String small;
                public String large;
                public String medium;
            }
        }
    }
}

點擊請求數據按鈕。獲取到返回的數據如下:

列表 ![Uploading 08_178546.png . . .]數據

當然,TestPresenterImpl中的內容是重點,其中getMovieListData()方法里的內容是retrofit和rxjava最基本的用法!想必大家多少都見過。我們再來看下rxjava相關的代碼,其實它主要做了三個事情。統一管理主線程、工作線程、請求返回后的回調處理!引入rxjava之前,三者都是自己管理。所以說,它的引入極大的簡化了我們的工作。

08.png

下一篇將講述優化封裝

相關鏈接

(四)安卓框架搭建之MVP+Retrofit+RxJava優化

github源碼地址

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