Android 工作经理一次请求 returns 工作人员的空白结果

Question

我正在使用 Work Manger 进行网络调用并获取一些数据，为此我使用了 OneTimeRequest。调用在工作人员 class 内完美响应，但它 returns 空白导致正在监视工作的生命周期所有者。

workManager= WorkManager.getInstance();
    OneTimeWorkRequest.Builder encryptionWork =new OneTimeWorkRequest.Builder(NetworkWorker.class);

    getUsersWorkReq=encryptionWork.setInputData(getWorkerInput(EXPERT_LIST_REQUEST))
            .addTag(Constant.WORK_GETUSER)
            .build();

    workManager.enqueue(getUsersWorkReq);

观察工作人员的反应class

 workManager.getStatusById(getUsersWorkReq.getId()).observe(this, workStatus -> {
        if (workStatus != null && workStatus.getState().isFinished()) {
            String status=workStatus.getOutputData().getString(Constant.WORK_RESULT);
            String response=workStatus.getOutputData().getString(Constant.WORK_RESPONSE);
            if(status!=null && !status.equalsIgnoreCase("")){
            }
        }
    });

但问题是，响应字符串始终为空！！即使工作经理已完成任务并且工作人员中有网络响应，但当我使用 setOutputData 时它会提供空白数据。

outPut = new Data.Builder()
                        .putString(Constant.WORK_RESULT,Constant.WORK_SUCCESS)
                        .putString(Constant.WORK_RESPONSE, String.valueOf(response.body()))
                        .build();
                Log.e("WORKER", "onResponse: "+ response.body().getMsg() );
                setOutputData(outPut);

工人Class

public class NetworkWorker extends Worker {
Data outPut;
@NonNull
@Override
public Result doWork() {

        ApiService service = RetrofitInstance.getRetrofitInstance().create(ApiService.class);

        Call<ExpertListResponse> call = service.get_recommended_users();

        Log.wtf("URL Called", call.request().url() + "");

        call.enqueue(new Callback<ExpertListResponse>() {
            @Override
            public void onResponse(Call<ExpertListResponse> call, Response<ExpertListResponse> response) {
                //onFinishedListener.onFinished(requestTag, response.body() != null ? response.body().getExpertInfo() : null);
                Data outPut = new Data.Builder()
                        .putString(Constant.WORK_RESULT,Constant.WORK_SUCCESS)
                        .putString(Constant.WORK_RESPONSE, String.valueOf(response.code()))
                        .build();
                Log.e("WORKER", "onResponse: "+ response.body().getMsg() );
                setOutputData(outPut);
            }

            @Override
            public void onFailure(Call<ExpertListResponse> call, Throwable t) {
                //onFinishedListener.onFailure(requestTag,t);
                Data outPut = new Data.Builder()
                        .putString(Constant.WORK_RESULT,Constant.WORK_FAILURE)
                        .putString(Constant.WORK_RESPONSE, String.valueOf(t))
                        .build();
                setOutputData(outPut);
            }
        });

    return Result.SUCCESS;
}

}

Answer 1

问题是您在触发 onResponse 之前返回 Result.Success，因为您正在执行异步改造请求，因此没有数据被设置为工作状态。

众多解决方法之一是您在您的 worker 中发送同步改造请求，因此您的 doWork() 方法将被阻止，直到您获得网络响应。您必须将异步改装请求更改为同步，类似于以下代码片段：

    public Result doWork() {
       try {
          ApiService service = RetrofitInstance.getRetrofitInstance()
                                   .create(ApiService.class);
          Call<ExpertListResponse> call = service.get_recommended_users();
          ExpertListResponse response = call.execute().body();
          Data outPut = new Data.Builder()
                    .putString(Constant.WORK_RESULT,Constant.WORK_SUCCESS)
                    .putString(Constant.WORK_RESPONSE, String.valueOf(response.code()))
                    .build();

          setOutputData(outPut);
          return Result.SUCCESS;
       } catch(Exception ex){
            Data outPut = new Data.Builder()
                    .putString(Constant.WORK_RESULT,Constant.WORK_FAILURE)
                    .putString(Constant.WORK_RESPONSE, String.valueOf(t))
                    .build();
            setOutputData(outPut);
            return Result.Failure;
       }
    }

Answer 2

你也可以这样使用：

public class NetworkWorker extends Worker {

private static final long MAX_WAIT_TIME_SECONDS = 10L;

Data outPut;
CountDownLatch latch;

@NonNull
@Override
public Result doWork() {
    // Need to wait for the onResponse() call.
    latch = new CountDownLatch(1);

    ApiService service = RetrofitInstance.getRetrofitInstance().create(ApiService.class);
    Call<ExpertListResponse> call = service.get_recommended_users();
    call.enqueue(new Callback<ExpertListResponse>() {
        @Override
        public void onResponse(Call<ExpertListResponse> call, Response<ExpertListResponse> response) {
            Data outPut = new Data.Builder()
                    .putString(Constant.WORK_RESULT,Constant.WORK_SUCCESS)
                    .putString(Constant.WORK_RESPONSE, String.valueOf(response.code()))
                    .build();
            Log.e("WORKER", "onResponse: "+ response.body().getMsg() );
            latch.countdown();
            setOutputData(outPut);
        }

        @Override
        public void onFailure(Call<ExpertListResponse> call, Throwable t) {
            Data outPut = new Data.Builder()
                    .putString(Constant.WORK_RESULT,Constant.WORK_FAILURE)
                    .putString(Constant.WORK_RESPONSE, String.valueOf(t))
                    .build();
            latch.countdown();
            setOutputData(outPut);
        }
    });

latch.await(MAX_WAIT_TIME_SECONDS, TimeUnit.SECONDS);
return Result.SUCCESS;

}

想法是通过 Retrofit 本身公开同步 API，或者使用 CountDownLatch。请记住，当您执行此类操作时，您可能会在线程池中使用额外的线程（因为 Retrofit 可能会使用不同的线程池）。

Answer 3

==========================Activity==========================


OneTimeWorkRequest movieOneTimeRequest;
WorkManager workManager;

private void callWorkerApiInBackground() {
        Constraints constraints = new Constraints.Builder()
                .setRequiredNetworkType(NetworkType.CONNECTED)
                .build();

        Data inputData = createInputData();

        movieOneTimeRequest = new OneTimeWorkRequest.Builder(MovieWorker.class)
                .setConstraints(constraints)
                .setInputData(inputData)
                .build();
        workManager.getWorkInfoByIdLiveData(movieOneTimeRequest.getId()).observe(this, workInfo -> {
            if (workInfo != null) {
                Log.e(TAG, "WorkInfo received: state: " + workInfo.getState());
                switch(workInfo.getState()){
                    case FAILED:
                        Log.e(TAG, "OBSERVING :: fail");
                        break;
                    case BLOCKED:
                        Log.e(TAG, "OBSERVING :: blocked");
                        break;
                    case RUNNING:
                        Log.e(TAG, "OBSERVING :: running");
                        break;
                    case ENQUEUED:
                        Log.e(TAG, "OBSERVING :: enqueued");
                        break;
                    case CANCELLED:
                        Log.e(TAG, "OBSERVING :: cancelled");
                        break;
                    case SUCCEEDED:
                        Log.e(TAG, "OBSERVING :: succeeded");
                        String workManagerOutput = workInfo.getOutputData().getString(MovieWorker.KEY_OUTPUT);
                        Log.e(TAG, " workManagerOutput: " + workManagerOutput);
                        break;
                }

            }
        });

        workManager.enqueue(movieOneTimeRequest);
    }

    private Data createInputData() {
        Data.Builder builder = new Data.Builder();
        String imageUrl = "www.image.come";
        if (!TextUtils.isEmpty(imageUrl)) {
            builder.putString(MovieWorker.KEY_IMAGE,imageUrl);
        }
        return builder.build();
    }

=================================== MovieWorker ========= ==============

    import android.content.Context;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.work.Data;
import androidx.work.Worker;
import androidx.work.WorkerParameters;

import com.aiplocationtest.models.MovieData;
import com.aiplocationtest.network.NetworkApiClient;

import java.util.List;

public class MovieWorker extends Worker {
    public static final String KEY_IMAGE = "image";
    public static final String KEY_OUTPUT = "output";
    String TAG = MovieWorker.class.getSimpleName();
    String imageUrl;

    public MovieWorker(@NonNull Context context, @NonNull WorkerParameters workerParams) {
        super(context, workerParams);
        imageUrl = workerParams.getInputData().getString(KEY_IMAGE);
        Log.e(TAG, " imageUrl : " + imageUrl);
    }

    @NonNull
    @Override
    public Result doWork() {
        try {
            List<MovieData> response = NetworkApiClient.getMovieList().execute().body();

            Data outputData = new Data.Builder()
                    .putString(KEY_OUTPUT, response.toString())
                    .build();
            return Result.success(outputData);
//            return  Result.success();
        } catch (Exception e) {
            e.printStackTrace();
            Log.e(TAG, " callMovieListApi Exception : " + e.getMessage());
            return Result.failure();
        }

    }
}

======================NetworkApiClient ====================

import com.aiplocationtest.models.MovieData;

import java.util.List;

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Call;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
import retrofit2.http.GET;

public class NetworkApiClient {


    public static Retrofit getRestAdapter() {
        HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor();
        interceptor.setLevel(HttpLoggingInterceptor.Level.BODY);

        OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build();
        return new Retrofit.Builder()
                .baseUrl(HttpConstant.BASE_URL)
                .client(client)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
    }

    public static Call<List<MovieData>> getMovieList() {
        return getRestAdapter().create(GetAPi.class).getMovieList();
    }

    public interface GetAPi {

        @GET(HttpConstant.MOVIE_LIST)
        Call<List<MovieData>> getMovieList();

    }


}

Android 工作经理一次请求 returns 工作人员的空白结果

Android Work Manager One time Request returns blank result from worker

android

android-workmanager