详解RxJava2 Retrofit2 网络框架简洁轻便封装

前言

RxJava2、Retrofit2火了有一段时间了，前段时间给公司的项目引入了这方面相关的技术，在此记录一下相关封装的思路。

需求

封装之前要先明白需要满足哪些需求。

1. RxJava2衔接Retrofit2
2. Retrofit2网络框架异常的统一处理
3. 兼容fastjson（可选）
4. RxJava2内存泄漏的处理
5. 异步请求加入Loading Dialog

依赖

implementation 'io.reactivex.rxjava2:rxandroid:2.0.1'
 implementation 'io.reactivex.rxjava2:rxjava:2.1.3'
 implementation 'com.squareup.retrofit2:retrofit:2.3.0'
 implementation 'com.squareup.retrofit2:adapter-rxjava2:2.3.0'
 implementation 'com.squareup.okhttp3:okhttp:3.9.0'
 implementation 'com.trello.rxlifecycle2:rxlifecycle-components:2.2.0'
 implementation 'com.alibaba:fastjson:1.1.59.android'//可选其它框架比如Gson

RxJava2衔接Retrofit2

先封装一个网络框架的管理类，方便调用

public class RxHttp {
 private final String BASE_URL = "https://github.com/";
 private Map<String, Retrofit> mRetrofitMap = new HashMap<>();
 private RxHttp() {

 }

 /**
  * 单例模式
  * @return
  */
 public static RxHttp getInstance() {
  return RxHttpHolder.sInstance;
 }

 private static class RxHttpHolder{
  private final static RxHttp sInstance = new RxHttp();
 }

 public Retrofit getRetrofit(String serverUrl) {
  Retrofit retrofit;
  if (mRetrofitMap.containsKey(serverUrl)) {
   retrofit = mRetrofitMap.get(serverUrl);
  } else {
   retrofit = createRetrofit(serverUrl);
   mRetrofitMap.put(serverUrl, retrofit);
  }
  return retrofit;
 }

 public SyncServerService getSyncServer(){
  return getRetrofit(BASE_URL).create(SyncServerService.class);
 }

 /**
  *
  * @param baseUrl baseUrl要以/作为结尾 eg：https://github.com/
  * @return
  */
 private Retrofit createRetrofit(String baseUrl) {
  OkHttpClient client = new OkHttpClient().newBuilder()
    .readTimeout(30, TimeUnit.SECONDS)
    .connectTimeout(30, TimeUnit.SECONDS)
    .retryOnConnectionFailure(true)
    .build();

  return new Retrofit.Builder()
    .baseUrl(baseUrl)
    .addConverterFactory(FastJsonConverterFactory.create())
    .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
    .client(client)
    .build();
 }

}

Restful风格接口

public interface SyncServerService {
 @GET("service/mobile/IsLatestVersion.ashx")
 Observable<Response<String>> getLatestVersion(@Query("SoftwareID") String SoftwareID,
             @Query("ClientVersion") String ClientVersion);
}

服务端返回的基本类型，在导入类的时候特别需要注意区分该Response类型

public class Response<T> {
 public int ret;//约定 -1为server返回数据异常 200为正常范围
 public String msg;
 public T data;

 public int getRet() {
  return ret;
 }

 public void setRet(int ret) {
  this.ret = ret;
 }

 public String getMsg() {
  return msg;
 }

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

 public T getData() {
  return data;
 }

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

fastjson的支持

由于项目中采用了fastjson，square尚未实现对fastjson的支持，但是保留了代码的扩展，这边可以自己封装一下fastjson的转换器。

public class FastJsonConverterFactory extends Converter.Factory {
 private final SerializeConfig mSerializeConfig;
 private FastJsonConverterFactory(SerializeConfig serializeConfig) {
  this.mSerializeConfig = serializeConfig;
 }

 public static FastJsonConverterFactory create() {
  return create(SerializeConfig.getGlobalInstance());
 }

 public static FastJsonConverterFactory create(SerializeConfig serializeConfig) {
  return new FastJsonConverterFactory(serializeConfig);
 }

 @Override
 public Converter<?, RequestBody> requestBodyConverter(Type type, Annotation[] parameterAnnotations, Annotation[] methodAnnotations, Retrofit retrofit) {
  return new FastJsonRequestBodyConverter<>(mSerializeConfig);
 }

 @Override
 public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
  return new FastJsonResponseBodyConvert<>(type);
 }
}

final class FastJsonRequestBodyConverter<T> implements Converter<T, RequestBody> {
 private final MediaType MEDIA_TYPE = MediaType.parse("application/json; charset=UTF-8");
 private SerializeConfig mSerializeConfig;
 public FastJsonRequestBodyConverter(SerializeConfig serializeConfig) {
  this.mSerializeConfig = serializeConfig;
 }

 @Override
 public RequestBody convert(T value) throws IOException {
  return RequestBody.create(MEDIA_TYPE, JSON.toJSONBytes(value, mSerializeConfig));
 }
}

final class FastJsonResponseBodyConvert<T> implements Converter<ResponseBody, T> {
 private Type mType;
 public FastJsonResponseBodyConvert(Type type) {
  this.mType = type;
 }

 @Override
 public T convert(ResponseBody value) throws IOException {
  return JSON.parseObject(value.string(), mType);
 }
}

数据返回统一处理

public abstract class BaseObserver<T> implements Observer<Response<T>> {
 @Override
 public final void onNext(@NonNull Response<T> result) {
  if (result.getRet() == -1) {
   onFailure(new Exception(result.getMsg()), result.getMsg());//该异常可以汇报服务端
  } else {
   onSuccess(result.getData());
  }
 }

 @Override
 public void onError(@NonNull Throwable e) {
  onFailure(e, RxExceptionUtil.exceptionHandler(e));
 }

 @Override
 public void onComplete() {
 }

 @Override
 public void onSubscribe(@NonNull Disposable d) {
 }

 public abstract void onSuccess(T result);
 public abstract void onFailure(Throwable e, String errorMsg);
}

下面加入了异常处理类

public class RxExceptionUtil {
 public static String exceptionHandler(Throwable e){
  String errorMsg = "未知错误";
  if (e instanceof UnknownHostException) {
   errorMsg = "网络不可用";
  } else if (e instanceof SocketTimeoutException) {
   errorMsg = "请求网络超时";
  } else if (e instanceof HttpException) {
   HttpException httpException = (HttpException) e;
   errorMsg = convertStatusCode(httpException);
  } else if (e instanceof ParseException || e instanceof JSONException
    || e instanceof com.alibaba.fastjson.JSONException) {
   errorMsg = "数据解析错误";
  }
  return errorMsg;
 }

 private static String convertStatusCode(HttpException httpException) {
  String msg;
  if (httpException.code() >= 500 && httpException.code() < 600) {
   msg = "服务器处理请求出错";
  } else if (httpException.code() >= 400 && httpException.code() < 500) {
   msg = "服务器无法处理请求";
  } else if (httpException.code() >= 300 && httpException.code() < 400) {
   msg = "请求被重定向到其他页面";
  } else {
   msg = httpException.message();
  }
  return msg;
 }
}

异步请求加入Loading Dialog

这个时候我们可以根据自己项目中统一封装的dialog自行扩展BaseObserver

public abstract class ProgressObserver<T> extends BaseObserver<T>{
 private MaterialDialog mMaterialDialog;
 private Context mContext;
 private String mLoadingText;
 public ProgressObserver(Context context){
  this(context, null);
 }

 public ProgressObserver(Context context, String loadingText){
  mContext = context;
  mLoadingText = loadingText;
 }

 @Override
 public void onSubscribe(@NonNull Disposable d) {
  if (!d.isDisposed()) {
   mMaterialDialog = new MaterialDialog.Builder(mContext).content(mLoadingText == null ? "正在加载中..."
     : mLoadingText).isProgress(true).build();
   mMaterialDialog.show();
  }
 }

 @Override
 public void onComplete() {
  if (mMaterialDialog != null) {
   mMaterialDialog.dismiss();
  }
 }

 @Override
 public void onError(@NonNull Throwable e) {
  super.onError(e);
  if (mMaterialDialog != null) {
   mMaterialDialog.dismiss();
  }
 }

}

加入调度类，方便调用线程切换和解决内存泄漏的问题

public class RxSchedulers {
 public static <T> ObservableTransformer<T, T> observableIO2Main(final Context context) {
  return upstream -> {
   Observable<T> observable = upstream.subscribeOn(Schedulers.io())
     .observeOn(AndroidSchedulers.mainThread());
   return composeContext(context, observable);
  };
 }

 public static <T> ObservableTransformer<T, T> observableIO2Main(final RxFragment fragment) {
  return upstream -> upstream.subscribeOn(Schedulers.io())
    .observeOn(AndroidSchedulers.mainThread()).compose(fragment.<T>bindToLifecycle());
 }

 private static <T> ObservableSource<T> composeContext(Context context, Observable<T> observable) {
  if(context instanceof RxActivity) {
   return observable.compose(((RxActivity) context).bindUntilEvent(ActivityEvent.DESTROY));
  } else if(context instanceof RxFragmentActivity){
   return observable.compose(((RxFragmentActivity) context).bindUntilEvent(ActivityEvent.DESTROY));
  }else if(context instanceof RxAppCompatActivity){
   return observable.compose(((RxAppCompatActivity) context).bindUntilEvent(ActivityEvent.DESTROY));
  }else {
   return observable;
  }
 }
}

讲了那么多，那么如何使用这个封装呢？下面来看下如何使用。

RxHttp.getInstance().getSyncServer().getLatestVersion("1", "1.0.0")
    .compose(RxSchedulers.observableIO2Main(this))
    .subscribe(new ProgressObserver<String>(this) {
     @Override
     public void onSuccess(String result) {
      Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT).show();
     }

     @Override
     public void onFailure(Throwable e, String errorMsg) {
     }
    });

是不是封装后的代码显得更为简洁一点呢？以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持我们。