Android--Retrofit+RxJava的简单封装（三）

1，继续接着上一篇的讲讲，话说如果像上一篇这样的话，那么我们每一次请求一个结构都要创建一堆的Retrofit对象，而且代码都是相同的，我们可以试试封装一下

先创建一个HttpMethods类，将Retrofit对象创建封装起来

HttpMethods.java

package com.qianmo.retrofitdemo.http;

import com.qianmo.retrofitdemo.entry.MovieEntity;

import java.util.concurrent.TimeUnit;

import okhttp3.OkHttpClient;
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;

/**
 * Created by wangjitao on 2016/11/3 0003.
 * 对Retrofit的的简单封装
 */
public class HttpMethods {

    public static final String BASE_URL = "https://api.douban.com/v2/movie/";
    private static final int DEFAULT_TIMEOUT = 5;

    private Retrofit retrofit;

    private MovieService movieService;

    //先构造私有的构造方法
    private HttpMethods() {
        //手动创建一个OkHttpClient并设置超时时间
        OkHttpClient.Builder httpClientBuilder = new OkHttpClient.Builder();
        httpClientBuilder.connectTimeout(DEFAULT_TIMEOUT, TimeUnit.SECONDS);

        retrofit = new Retrofit.Builder()
                .client(httpClientBuilder.build())
                .addConverterFactory(GsonConverterFactory.create())
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
                .baseUrl(BASE_URL)
                .build();
        movieService = retrofit.create(MovieService.class);
    }

    //创建单例
    public static class SingleonHolder {
        private static final HttpMethods instance = new HttpMethods();
    }

    //获取单例
    public static HttpMethods getInstance() {
        return SingleonHolder.instance;
    }

    /**
     *
     * @param start 起始位置
     * @param count 获取长度
     * @param subscriber 传递过来的观察者对象
     */
    public void getTopMovie(int start, int count, Subscriber<MovieEntity> subscriber) {
        movieService.getTopMovie(start, count)
                .subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(subscriber);
    }
}

在直接在Activity中进行调用

package com.qianmo.retrofitdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.qianmo.retrofitdemo.entry.MovieEntity;
import com.qianmo.retrofitdemo.http.HttpMethods;
import com.qianmo.retrofitdemo.http.MovieService;

import butterknife.Bind;
import butterknife.ButterKnife;
import butterknife.OnClick;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
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;

public class MainActivity extends AppCompatActivity {

    @Bind(R.id.tv_show)
    TextView tvShow;
    @Bind(R.id.btn_request)
    Button btnRequest;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
    }

    @OnClick({R.id.btn_request})
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_request:
                getMovie();
                break;
        }
    }

    //请求网络数据
    private void getMovie() {

//        //https://api.douban.com/v2/movie/top250?start=0&count=10 目标地址
//        String baseUrl = "https://api.douban.com/v2/movie/";
//
//        //创建Retrofit对象
//        Retrofit retrofit = new Retrofit.Builder()
//                .baseUrl(baseUrl)
//                .addConverterFactory(GsonConverterFactory.create())
//                .build();
//
//        MovieService movieService = retrofit.create(MovieService.class);
//        Call<MovieEntity> call = movieService.getTopMovie(0, 10);
//        call.enqueue(new Callback<MovieEntity>() {
//            @Override
//            public void onResponse(Call<MovieEntity> call, Response<MovieEntity> response) {
//                tvShow.setText(response.body().getTitle());
//            }
//
//            @Override
//            public void onFailure(Call<MovieEntity> call, Throwable t) {
//                tvShow.setText(t.getMessage());
//            }
//        });

        //第二种
//        String baseUrl = "https://api.douban.com/v2/movie/";
//
//        Retrofit retrofit = new Retrofit.Builder()
//                .baseUrl(baseUrl)
//                .addConverterFactory(GsonConverterFactory.create())
//                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
//                .build();
//        MovieService movieService = retrofit.create(MovieService.class);
//
//        movieService.getTopMovie(0, 10)
//                .subscribeOn(Schedulers.io())
//                .observeOn(AndroidSchedulers.mainThread())
//                .subscribe(new Subscriber<MovieEntity>() {
//                    @Override
//                    public void onCompleted() {
//                        Toast.makeText(MainActivity.this, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
//                    }
//
//                    @Override
//                    public void onError(Throwable e) {
//                        tvShow.setText(e.getMessage());
//                    }
//
//                    @Override
//                    public void onNext(MovieEntity movieEntity) {
//                        tvShow.setText(movieEntity.getTitle());
//                    }
//                });
        HttpMethods.getInstance().getTopMovie(0, 10, new Subscriber<MovieEntity>() {
            @Override
            public void onCompleted() {
                Toast.makeText(MainActivity.this, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(Throwable e) {
                tvShow.setText(e.getMessage());
            }

            @Override
            public void onNext(MovieEntity movieEntity) {
                tvShow.setText(movieEntity.getTitle());
            }
        });
    }


}

但是现在存在一个问题，当存在相同格式的数据时候  我们应该怎么封装，一般来说我们后台返给我们的数据是这样的：

{
 "resultCode": 0,
 "resultMessage": "成功",
 "data": {}
}

　主要的数据是data，然后通过code来判断是否请求成功  由于data里面的数据是多变的 可以是一个对象也可以是一个数组 这时候我们需要创建一个HttpResult

package com.qianmo.retrofitdemo.http;

/**
 * Created by Administrator on 2016/11/3 0003.
 */
public class HttpResult<T> {
    private int resultCode ;
    private String resultMessage ;

    private T data ;


}

用过我们这次借口的同学都知道我们这次接口其实不是这样的，先来看看我们这次的数据结构吧

{
    "count": 10, 
    "start": 0, 
    "total": 250, 
    "subjects": [], 
    "title": "豆瓣电影Top250"
}

我们打算通过count的数量来判断请求是否成功，所以吧HttpResult类修改成下面

package com.qianmo.retrofitdemo.http;

/**
 * Created by Administrator on 2016/11/3 0003.
 */
public class HttpResult<T> {
//    常用形式
//    private int resultCode ;
//    private String resultMessage ;
//
//    private T data ;

    //本次接口的数据结构
    private int count;
    private int start;
    private int total;
    private String title;

    //用来模仿Data
    private T subjects;


    public int getCount() {
        return count;
    }

    public void setCount(int count) {
        this.count = count;
    }

    public int getStart() {
        return start;
    }

    public void setStart(int start) {
        this.start = start;
    }

    public int getTotal() {
        return total;
    }

    public void setTotal(int total) {
        this.total = total;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }


    public T getSubjects() {
        return subjects;
    }

    public void setSubjects(T subjects) {
        this.subjects = subjects;
    }


    @Override
    public String toString() {
        StringBuffer sb = new StringBuffer();
        sb.append("title=" + title + " count=" + count + " start=" + start);
        if (null != subjects) {
            sb.append(" subjects:" + subjects.toString());
        }
        return sb.toString();
    }

}

在正常服务器返回的数据下code=200或者code=0的时候是表示成功的，但是由于我们这次的接口没有这一块的内容，所以打算使用count字段来判断，当coun = 0的时候表示没有数据，请求失败，所以这里我们需要在HttpMethod类中添加一个判断的方法

/**
     * 用来处理请求的code
     * @param <T>
     */
    private class HttpResultFunc<T> implements Func1<HttpResult<T>, T> {
        @Override
        public T call(HttpResult<T> tHttpResult) {
            if (tHttpResult.getCount() == 0) {
                throw new ApiException(100);
            }
            return tHttpResult.getSubjects();
        }
    }

所以getMovie()　方法修改成了

/**
     * 用于获取豆瓣电影Top250的数据
     * @param subscriber  由调用者传过来的观察者对象
     * @param start 起始位置
     * @param count 获取长度
     */
    public void getTopMovie(Subscriber<List<Subject>> subscriber, int start, int count){

        movieService.getTopMovie(start, count)
                .map(new HttpResultFunc<List<Subject>>())
                .subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(subscriber);
}

ok，在修改一下activity中的调用方法

HttpMethods.getInstance().getTopMovie(0, 10, new Subscriber<List<Subject>>() {
            @Override
            public void onCompleted() {
                Toast.makeText(MainActivity.this, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onError(Throwable e) {
                tvShow.setText(e.getMessage());
            }

            @Override
            public void onNext(List<Subject> subjects) {
                StringBuffer sb = new StringBuffer();
                for (Subject subject : subjects) {
                    sb.append(subject.toString());
                }
                tvShow.setText(sb);
            }
        });

让我们看一下效果：（截取的动态图又太大了！！上传不了）

　

　但是这也不是我们想要的最终结果，在请求数据的时候显示加载框，在请求完成的时候或者请求出错的时候影藏掉加载框，这样的话才算一个正常的网络请求框架。由于使用了RxJava，所以要创建一个类，继承与Subscriber，由于Subscriver对象中有四个方法，onStart、onNext、onError、onCompleted方法，我们需要在onStart中显示进度框，在onCompleted和onError中隐藏掉加载框，由于activity只关心最后的数据，所以我们需要写一个接口回调，将onNext方法中的数据传递给activity，让activity去处理逻辑。

SubscriberOnNextListenter.java

package com.qianmo.retrofitdemo.http;

/**
 * Created by Administrator on 2016/11/3 0003.
 */
public interface SubscriberOnNextListenter<T> {
    void next(T t);
}

ProgressSubscriber.java

package com.qianmo.retrofitdemo.http;

import android.content.Context;
import android.widget.Toast;

import rx.Subscriber;

/**
 * Created by wangjitao on 2016/11/3 0003.
 */
public class ProgressSubscriber<T> extends Subscriber<T> {

    private SubscriberOnNextListenter mSubscriberOnNextListenter;
    private Context context;

    public ProgressSubscriber(SubscriberOnNextListenter mSubscriberOnNextListenter, Context context) {
        this.mSubscriberOnNextListenter = mSubscriberOnNextListenter;
        this.context = context;
    }

    @Override
    public void onStart() {
    }

    @Override
    public void onCompleted() {
        Toast.makeText(context, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onError(Throwable e) {
        Toast.makeText(context, "error:" + e.getMessage(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onNext(T t) {
        mSubscriberOnNextListenter.next(t);
    }
}

再来修改一下我们activity调用的代码

package com.qianmo.retrofitdemo;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.qianmo.retrofitdemo.entry.Subject;
import com.qianmo.retrofitdemo.http.HttpMethods;
import com.qianmo.retrofitdemo.http.ProgressSubscriber;
import com.qianmo.retrofitdemo.http.SubscriberOnNextListenter;

import java.util.List;

import butterknife.Bind;
import butterknife.ButterKnife;
import butterknife.OnClick;
import rx.Subscriber;

public class MainActivity extends AppCompatActivity {

    @Bind(R.id.tv_show)
    TextView tvShow;
    @Bind(R.id.btn_request)
    Button btnRequest;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
    }

    @OnClick({R.id.btn_request})
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.btn_request:
                getMovie();
                break;
        }
    }

    //请求网络数据
    private void getMovie() {

//        //https://api.douban.com/v2/movie/top250?start=0&count=10 目标地址
//        String baseUrl = "https://api.douban.com/v2/movie/";
//
//        //创建Retrofit对象
//        Retrofit retrofit = new Retrofit.Builder()
//                .baseUrl(baseUrl)
//                .addConverterFactory(GsonConverterFactory.create())
//                .build();
//
//        MovieService movieService = retrofit.create(MovieService.class);
//        Call<MovieEntity> call = movieService.getTopMovie(0, 10);
//        call.enqueue(new Callback<MovieEntity>() {
//            @Override
//            public void onResponse(Call<MovieEntity> call, Response<MovieEntity> response) {
//                tvShow.setText(response.body().getTitle());
//            }
//
//            @Override
//            public void onFailure(Call<MovieEntity> call, Throwable t) {
//                tvShow.setText(t.getMessage());
//            }
//        });

        //第二种
//        String baseUrl = "https://api.douban.com/v2/movie/";
//
//        Retrofit retrofit = new Retrofit.Builder()
//                .baseUrl(baseUrl)
//                .addConverterFactory(GsonConverterFactory.create())
//                .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
//                .build();
//        MovieService movieService = retrofit.create(MovieService.class);
//
//        movieService.getTopMovie(0, 10)
//                .subscribeOn(Schedulers.io())
//                .observeOn(AndroidSchedulers.mainThread())
//                .subscribe(new Subscriber<MovieEntity>() {
//                    @Override
//                    public void onCompleted() {
//                        Toast.makeText(MainActivity.this, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
//                    }
//
//                    @Override
//                    public void onError(Throwable e) {
//                        tvShow.setText(e.getMessage());
//                    }
//
//                    @Override
//                    public void onNext(MovieEntity movieEntity) {
//                        tvShow.setText(movieEntity.getTitle());
//                    }
//                });
        //第三种
//        HttpMethods.getInstance().getTopMovie(0, 10, new Subscriber<List<Subject>>() {
//            @Override
//            public void onCompleted() {
//                Toast.makeText(MainActivity.this, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
//            }
//
//            @Override
//            public void onError(Throwable e) {
//                tvShow.setText(e.getMessage());
//            }
//
//            @Override
//            public void onNext(List<Subject> subjects) {
//                StringBuffer sb = new StringBuffer();
//                for (Subject subject : subjects) {
//                    sb.append(subject.toString());
//                }
//                tvShow.setText(sb);
//            }
//        });
        SubscriberOnNextListenter subscriberOnNextListenter = new SubscriberOnNextListenter() {
            @Override
            public void next(Object o) {

            }
        };
        //第四种
        HttpMethods.getInstance()
                .getTopMovie(0, 10, new ProgressSubscriber<List<Subject>>(
                        new SubscriberOnNextListenter<List<Subject>>() {
                            @Override
                            public void next(List<Subject> subjects) {
                                StringBuffer sb = new StringBuffer();
                                for (Subject subject : subjects) {
                                    sb.append(subject.toString());
                                }
                                tvShow.setText(sb);
                            }
                        }, MainActivity.this));

    }


}

再加上取消加载的接口和封装的progress就基本上完成了

package com.qianmo.retrofitdemo.http;

public interface ProgressCancelListener {
    void onCancelProgress();
}

package com.qianmo.retrofitdemo.http;

import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Handler;
import android.os.Message;

/**
 * Created by liukun on 16/3/10.
 */
public class ProgressDialogHandler extends Handler {

    public static final int SHOW_PROGRESS_DIALOG = 1;
    public static final int DISMISS_PROGRESS_DIALOG = 2;

    private ProgressDialog pd;

    private Context context;
    private boolean cancelable;
    private ProgressCancelListener mProgressCancelListener;

    public ProgressDialogHandler(Context context, ProgressCancelListener mProgressCancelListener,
                                 boolean cancelable) {
        super();
        this.context = context;
        this.mProgressCancelListener = mProgressCancelListener;
        this.cancelable = cancelable;
    }

    private void initProgressDialog(){
        if (pd == null) {
            pd = new ProgressDialog(context);

            pd.setCancelable(cancelable);

            if (cancelable) {
                pd.setOnCancelListener(new DialogInterface.OnCancelListener() {
                    @Override
                    public void onCancel(DialogInterface dialogInterface) {
                        mProgressCancelListener.onCancelProgress();
                    }
                });
            }

            if (!pd.isShowing()) {
                pd.show();
            }
        }
    }

    private void dismissProgressDialog(){
        if (pd != null) {
            pd.dismiss();
            pd = null;
        }
    }

    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case SHOW_PROGRESS_DIALOG:
                initProgressDialog();
                break;
            case DISMISS_PROGRESS_DIALOG:
                dismissProgressDialog();
                break;
        }
    }

}

progressSubscriber.java

package com.qianmo.retrofitdemo.http;

import android.content.Context;
import android.widget.Toast;

import java.net.ConnectException;
import java.net.SocketTimeoutException;

import rx.Subscriber;

/**
 * Created by wangjitao on 2016/11/3 0003.
 */
public class ProgressSubscriber<T> extends Subscriber<T> implements ProgressCancelListener {

    private SubscriberOnNextListenter mSubscriberOnNextListenter;
    private ProgressDialogHandler mProgressDialogHandler;
    private Context context;

    public ProgressSubscriber(SubscriberOnNextListenter mSubscriberOnNextListenter, Context context) {
        this.mSubscriberOnNextListenter = mSubscriberOnNextListenter;
        this.context = context;
        mProgressDialogHandler = new ProgressDialogHandler(context, this, true);
    }

    /**
     * 在开始订阅的时候显示加载框
     */
    @Override
    public void onStart() {
        if (mProgressDialogHandler != null) {
            mProgressDialogHandler.obtainMessage(ProgressDialogHandler.SHOW_PROGRESS_DIALOG).sendToTarget();
        }
    }

    /**
     * 在完成的时候进行影藏
     */
    @Override
    public void onCompleted() {
        Toast.makeText(context, "Get Top Movie Completed", Toast.LENGTH_SHORT).show();
        dismissProgressDialog();
    }

    /**
     * 在出错的时候也进行影藏
     *
     * @param e
     */
    @Override
    public void onError(Throwable e) {
        if (e instanceof SocketTimeoutException) {
            Toast.makeText(context, "网络中断，请检查您的网络状态", Toast.LENGTH_SHORT).show();
        } else if (e instanceof ConnectException) {
            Toast.makeText(context, "网络中断，请检查您的网络状态", Toast.LENGTH_SHORT).show();
        } else {
            Toast.makeText(context, "error:" + e.getMessage(), Toast.LENGTH_SHORT).show();
        }
        dismissProgressDialog();
    }

    @Override
    public void onNext(T t) {
        mSubscriberOnNextListenter.next(t);
    }

    @Override
    public void onCancelProgress() {
        if (!this.isUnsubscribed()) {
            this.unsubscribe();
        }
    }

    private void showProgressDialog() {
        if (mProgressDialogHandler != null) {
            mProgressDialogHandler.obtainMessage(ProgressDialogHandler.SHOW_PROGRESS_DIALOG).sendToTarget();
        }
    }

    private void dismissProgressDialog() {
        if (mProgressDialogHandler != null) {
            mProgressDialogHandler.obtainMessage(ProgressDialogHandler.DISMISS_PROGRESS_DIALOG).sendToTarget();
            mProgressDialogHandler = null;
        }
    }
}

最后看一下效果

　　

　　

　

　　

　　

　　

　　

　　

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原文地址：https://www.cnblogs.com/wjtaigwh/p/6027301.html