Retrofit2与RxJava用法大全

Retrofit2是square公司出品的一个网络请求库，网上有很多相关的介绍。我很久以前都想去研究了，但一直都有各种事情耽搁，现在就让我们一起去捋一捋，这篇主要讲解Retrofit2与RxJava的基本用法。

• get请求

• post请求

• 文件上传

• 文件下载

• 开启日志拦截

• 与RxJava结合使用

什么是Retrofit2

官网是这么介绍的：

Retrofit adapts a Java interface to HTTP calls by using annotations on the declared methods to
define how requests are made。

我翻译的可能不准确，他的大概意思是说：Retrofit 是一个 java 接口类，以注解的方式用于 HTTP 网络请求。那下面我们一起来看看是怎么使用的？

使用前的配置

build.gradle 的 dependencies 添加：

    compile 'com.google.code.gson:gson:2.3.1'
    compile 'com.squareup.retrofit2:retrofit:2.0.0'
    compile 'com.squareup.retrofit2:converter-gson:2.0.0'
    compile 'com.squareup.okhttp3:logging-interceptor:3.2.0'

获取Retrofit实例

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("http://plus31.366ec.net/")
    .addConverterFactory(GsonConverterFactory.create())
    .build();

需要注意的是baseUrl添加的是地址的主域名。

申明RestService接口类

public interface RestService {
    @GET("/Route.axd?method=vast.Store.manager.list")
    Call<ResponseBody> getManagerData(@Query("StoreId") int id);
}

@GET 包含的是请求地址，是主域名之后的地址。举个例子，请求的

全地址：http://plus31.366ec.net/Route.axd?method=vast.Store.manager.list，

主域名为：http://plus31.366ec.net/

@GET包含的地址为：/Route.axd?method=vast.Store.manager.list

这样就完成了一个简单的@GET封装。

创建RestClient类

public class RestClient {

    private Retrofit mRetrofit;
    private static final String BASE_URL = "http://plus31.366ec.net/";
    private RestService mService;

    //构造方法
    public RestClient() {
        mRetrofit = new Retrofit.Builder()
                .baseUrl(BASE_URL)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        mService = mRetrofit.create(RestService.class);
    }

    public RestService getRectService() {
        if (mService != null) {
            return mService;
        }
        return null;
    }
}

这样就生成了一个简单的代理类，然后就可以进行相应请求了。

Get请求

public class SimpleGetActivity extends AppCompatActivity {

    private Button btnGet;
    private TextView tvResult;

    private RestClient mRestClient;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_simple_get);

        btnGet = (Button) findViewById(R.id.btn_get);
        tvResult = (TextView) findViewById(R.id.tv_result);

        btnGet.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //获取实例
                mRestClient = new RestClient();

                Call<ResponseBody> responseBodyCall = mRestClient.getRectService().getManagerData();
                //调用回调接口
                responseBodyCall.enqueue(new Callback<ResponseBody>() {
                    @Override
                    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                        try {
                            tvResult.setText(response.body().string());
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                    }

                    @Override
                    public void onFailure(Call<ResponseBody> call, Throwable t) {

                    }
                });
            }
        });
    }
}

一起来看看效果：

---

分析返回的 json数据，包含集合，那么我们可以进一步对接口返回值进行数据的封装。

BaseResponse类

public class BaseResponse<T> {

    @SerializedName("data")
    public List<T> managerList;

    @SerializedName("code")
    public int code;

    @SerializedName("message")
    public String message;
}

注意：BaseResponse类的字段，根据自己返回json数据新增或者删除。

根据返回的json集合，那么我们肯定有个实体类了。

Manager类

public class Manager {

    public int Id;

    public String UserName;

}

Manager 类你可以替换成你自己的实体类。

Get的进一步封装

@GET("/Route.axd?method=vast.Store.manager.list")
Call<BaseResponse<Manager>> getManagerDatas(@Query("StoreId") int id);

注意：我们这里对方法的返回值进行了一个修改Call<BaseResponse<Manager>>

来看看封装后的Activity类：

public class GetActivity extends AppCompatActivity {

    private Button btnGet;

    private RestClient mRestClient;

    private RecyclerView mRecyclerView;

    private BaseRecyclerAdapter<Manager> mAdapter;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_get);

        btnGet = (Button) findViewById(R.id.btn_get);
        mRecyclerView = (RecyclerView) findViewById(R.id.rv);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        btnGet.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //获取实例
                mRestClient = new RestClient();

                Call<BaseResponse<Manager>> baseResponseCall = mRestClient.getRectService().getManagerDatas();

                baseResponseCall.enqueue(new Callback<BaseResponse<Manager>>() {
                    @Override
                    public void onResponse(Call<BaseResponse<Manager>> call, Response<BaseResponse<Manager>> response) {
                        //获取返回的集合数据
                        //response.body().managerList
                        mAdapter = new BaseRecyclerAdapter<Manager>(GetActivity.this, response.body().managerList, R.layout.rv_item) {
                            @Override
                            protected void convert(BaseViewHolder helper, Manager item) {
                                helper.setText(R.id.tv_item_text, item.UserName);
                            }
                        };
                        mRecyclerView.setAdapter(mAdapter);
                    }

                    @Override
                    public void onFailure(Call<BaseResponse<Manager>> call, Throwable t) {

                    }
                });

            }
        });
    }
}

来看看效果：

---

Get常用技巧

HashMap组装参数：

@GET("/Route.axd?method=vast.Store.manager.list")
    Call<BaseResponse<Manager>> getManagerDatas(@QueryMap HashMap<String, String> hm);

Get 请求就讲到这里了，下面一起来看看 Post请求。

Post请求

 @FormUrlEncoded
    @POST("/Route.axd?method=vast.Store.manager.list")
    Call<BaseResponse<Manager>> postManagerDatas(@Field("StoreId") int id);

@Field("StoreId") int id可以替换@Body，@Body你可以传入HashMap、实体 beans 等对象。

注意：以@Body上传参数，会默认加上Content-Type: application/json; charset=UTF-8的请求头，即以JSON格式请求，再以JSON格式响应。

单个文件上传

 @Multipart
    @POST("/UploadProduct.axd")
    Call<ResponseBody> uploadSimpleFile(@Part MultipartBody.Part file);

文件上传稍微复杂点，具体请看以下代码：

 File file = new File("/sdcard/", "a.xlxs");
    //file
    RequestBody requestFile = RequestBody.create(MediaType.parse("multipart/form-data"), file);
    //监听上传进度
    CountingRequestBody countingRequestBody = new CountingRequestBody(requestFile, new CountingRequestBody.Liste
        @Override
        public void onRequestProgress(long bytesWritten, long contentLength) {
            tvFile.setText("上传进度:" + contentLength + ":" + bytesWritten);
        }
    });

    MultipartBody.Part body =
            MultipartBody.Part.createFormData("file", file.getName(),countingRequestBody);

    mRestClient = new RestClient("http://192.168.4.111:686/");

    Call<ResponseBody> responseBodyCall = mRestClient.getRectService().uploadSimpleFile(body);

    responseBodyCall.enqueue(new Callback<ResponseBody>() {
        @Override
        public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
            tvFile.setText("上传成功");
        }
        @Override
        public void onFailure(Call<ResponseBody> call, Throwable t) {
            tvFile.setText(t.toString());
        }
    });

看看效果图：

多文件上传

@Multipart
@POST("/HpWens/ProgressDemos/")
Call<ResponseBody> uploads(@PartMap Map<String, RequestBody> params);

private void initData() {
        //保证文件按顺序上传 使用LinkedHashMap
        params = new LinkedHashMap<>();

        File file1 = new File("/sdcard/", "a.xlxs");
        final RequestBody requestBody1 = RequestBody.create(MediaType.parse("multipart/form-data"), file1);
        //监听上传进度
        CountingRequestBody countingRequestBody1 = new CountingRequestBody(requestBody1, new CountingRequestBody.Listener() {
            @Override
            public void onRequestProgress(long bytesWritten, long contentLength) {
                tvFile1.setText("上传进度:" + contentLength + ":" + bytesWritten);
            }
        });

        params.put("file\";filename=\"" + file1.getName(), countingRequestBody1);

        File file2 = new File("/sdcard/", "a.xlxs");
        RequestBody requestBody2 = RequestBody.create(MediaType.parse("multipart/form-data"), file2);
        //监听上传进度
        CountingRequestBody countingRequestBody2 = new CountingRequestBody(requestBody2, new CountingRequestBody.Listener() {
            @Override
            public void onRequestProgress(long bytesWritten, long contentLength) {
                tvFile2.setText("上传进度:" + contentLength + ":" + bytesWritten);
            }
        });

        params.put("file\";filename=\"" + file2.getName(), countingRequestBody2);

        mRestClient = new RestClient("http://192.168.4.111:686/");

        btnUpload.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Call<ResponseBody> responseBodyCall = mRestClient.getRectService().uploadMultiFiles(params);
                responseBodyCall.enqueue(new Callback<ResponseBody>() {
                    @Override
                    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
                        tvFile1.setText("上传成功");
                        tvFile2.setText("上传成功");
                    }

                    @Override
                    public void onFailure(Call<ResponseBody> call, Throwable t) {

                    }
                });
            }
        });

    }

在文章的后面我会附上源码，这里我就不在贴图了，具体请看demo

文件下载

@Streaming
@GET("/image/h%3D360/sign=86aee1fbf1deb48fe469a7d8c01e3aef/{filename}")
Call<ResponseBody> downFile(@Path("filename") String fileName);

处理方式基本和上面几种差不多：

public class DownFileActivity extends AppCompatActivity {

    private ImageView iv;
    private Button btnDown;
    private RestClient mRestClient;

    private String fileName;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_down_file);

        iv = (ImageView) findViewById(R.id.iv);
        btnDown = (Button) findViewById(R.id.btn_down);

        mRestClient = new RestClient("http://d.hiphotos.baidu.com/");

        fileName = "b812c8fcc3cec3fd8757dcefd488d43f8794273a.jpg";

        btnDown.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Call<ResponseBody> userCall = mRestClient.getRectService().downFile(fileName);
                userCall.enqueue(new Callback<ResponseBody>() {
                    @Override
                    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {

                        iv.setImageBitmap(BitmapFactory.decodeStream(response.body().byteStream()));
                        //saveFile(response.body().byteStream());
                    }

                    @Override
                    public void onFailure(Call<ResponseBody> call, Throwable t) {

                    }
                });
            }
        });
    }

    public void saveFile(InputStream is){
        try {
            String fn = Environment.getExternalStorageDirectory() + "/" + fileName;
            FileOutputStream fos = new FileOutputStream(fn);
            byte[] buf = new byte[];
            int len;
            while ((len = is.read(buf)) != -) {
                fos.write(buf, , len);
            }
            is.close();
            fos.close();
        } catch (Exception ex) {

        }
    }
}

效果一览：

---

开启OKHttp的日志拦截

开启日志后，会记录request和response的相关信息，非常实用，也非常强大，不知道是否是编码格式，我下载图片打印的全是乱码。

public void initRestClint(String baseUrl) {
    logging.setLevel(HttpLoggingInterceptor.Level.BODY);
    OkHttpClient.Builder httpClient = new OkHttpClient.Builder();
    httpClient.addInterceptor(logging);
    mRetrofit = new Retrofit.Builder()
            .baseUrl(baseUrl)
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
            .client(httpClient.build())
            .build();
    mService = mRetrofit.create(RestService.class);
}

类似这样的logcat日志：

Retrofit2与RxJava结合使用

添加库：

   compile 'io.reactivex:rxandroid:1.1.0'
    compile 'com.squareup.retrofit2:adapter-rxjava:2.0.0'

添加addCallAdapterFactory(RxJavaCallAdapterFactory.create())到Retrofit.Builder中：

mRetrofit = new Retrofit.Builder()
        .baseUrl(baseUrl)
        .addConverterFactory(GsonConverterFactory.create())
        .addCallAdapterFactory(RxJavaCallAdapterFactory.create())
        .client(httpClient.build())
        .build();

那么我们结合RxJava一起使用呢，下面我们一起来看一看：

@GET("/Route.axd?method=vast.Store.manager.list")
Observable<BaseResponse<Manager>> getManagers(@Query("StoreId") int id);

通过我们的观察是不是发现只有返回值发送了变化，Observable类型。

//获取实例
mRestClient = new RestClient();
mRestClient.getRectService().getManagers()
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(new Subscriber<BaseResponse<Manager>>() {
            @Override
            public void onCompleted() {
            }
            @Override
            public void onError(Throwable e) {
            }
            @Override
            public void onNext(BaseResponse<Manager> managerBaseResponse) {

            }
        });

RxJava支持链式写法，可以处理一些很复杂的问题。

源码地址