如何从 Worker 获取输出数据？ (MVVM + WorkManager + Room)

分类：编程问答

如何解决如何从 Worker 获取输出数据？ (MVVM + WorkManager + Room)

我正在使用 MVVM 并将工作人员从我的存储库中排队。工作人员的工作只是将一些数据插入数据库，但我想在后台任务完成后访问一些输出数据，以便我可以验证数据是否顺利进入数据库。我尝试使用 WorkInfo.State 或使用 getOutputData 获取数据，但由于某种原因它似乎不起作用。关于如何实现这一目标的任何想法？

以下是代码供参考：

AddWorkoutWorker.java

public class AddWorkoutWorker extends Worker {

    public static final String WORK_WORKOUT_NAME = "workout";
    public static final String WORK_WORKOUT_TYPE = "type";
    public static final String WORK_FAILURE_TAG = "failed";
    public static final String WORK_SUCCESS_TAG = "success";
    private static final String WORKER_TAG = "Worker Tag";
    private WorkoutDAO workoutDAO;
    private AppDatabase database;
    Boolean workSuccess;

    //Worker constructor
    public AddWorkoutWorker(@NonNull Context context,@NonNull WorkerParameters workerParams) {
        super(context,workerParams);
        database = AppDatabase.getInstance(context);
        workoutDAO = database.workoutDAO();
    }

    @NonNull
    @Override
    public Result doWork() {

        //Gets input data
        Data inputData = getInputData();
        String workoutName = inputData.getString(WORK_WORKOUT_NAME);
        String workoutType = inputData.getString(WORK_WORKOUT_TYPE);


        if (workoutName != null && workoutType != null){
            //Inserts item in database through DAO
            Log.d(WORKER_TAG,"Worker data passed: "+workoutName + workoutType);
            Workout workout = new Workout(workoutName,workoutType);
            workoutDAO.insertSingleWorkout(workout);
        }else{
            //Returns false if the worker doesn't add the item to the database
            workSuccess = false;
            Data output = new Data.Builder()
                    .putBoolean(WORK_FAILURE_TAG,workSuccess)
                    .build();
            return Result.failure(output);
        }

        //Returns true if the worker adds the item to the database
        workSuccess = true;
        Data output = new Data.Builder()
                .putBoolean(WORK_SUCCESS_TAG,workSuccess)
                .build();

        return Result.success(output);
    }
}

AddWorkoutRepository.java

public class AddWorkoutRepository{

    private static final String REPOSITORY_TAG = "REPOSITORY TAG";
    public static final String WORKER_QUEUE_TAG = "Importing Single Workout";
    public WorkoutDAO workoutDAO;
    private final WorkManager workManager;
    private AppDatabase database;
    //private LiveData<List<Workout>> workouts;



    public AddWorkoutRepository(Application application){

        database = AppDatabase.getInstance(application);
        workoutDAO = database.workoutDAO();
        workManager = WorkManager.getInstance(application.getApplicationContext());
        //workouts = workoutDAO.getAllWorkoutsLiveData();

    }

    /*public LiveData<List<Workout>> getAllWorkouts(){
        return workouts;
    }*/

    public void insertWorkout(Workout workout){

        String workoutName = workout.getWorkoutName();
        String workoutType = workout.getWorkoutType();

        Log.d(REPOSITORY_TAG,"Insert Values passed: "+workoutName + workoutType);

        Data data = new Data.Builder()
                .putString(WORK_WORKOUT_NAME,workoutName)
                .putString(WORK_WORKOUT_TYPE,workoutType)
                .build();

        OneTimeWorkRequest importDataRequest = new OneTimeWorkRequest.Builder(AddWorkoutWorker.class)
                .setInputData(data)
                .addTag(WORKER_QUEUE_TAG)
                .build();

        workManager.enqueue(importDataRequest);

        Log.d(REPOSITORY_TAG,"After work manager task OK");

    }

}

解决方法

好的，所以我想通了。我使用了 WorkInfo 提供的 LiveData obj 来获取输出数据和任务状态。

  1. 我做的第一件事是在我的 ViewModel private LiveData<List<WorkInfo>> workerOutPut; 中声明 LiveData obj
  2. 然后在视图模型构造函数中像这样初始化我的 LiveData workerOutPut = workManager.getWorkInfosByTagLiveData(ADD_WORKOUT_WORKER_QUEUE_TAG);
  3. 为 LiveData 制作了一个 getter（当然在 ViewModel 中）
  4. 然后我只是在我的 Activity 中创建了一个 Observer，它根据我在 Worker 输出数据中设置的布尔值检查 Worker 的状态。

就是这样。我对这一切都很陌生，所以如果有人要添加任何内容，请随时添加。我会为其他新“玩家”发布完整代码以帮助他们。

Worker.java

public class AddWorkoutWorker extends Worker {

    public static final String WORK_WORKOUT_NAME = "workout";
    public static final String WORK_WORKOUT_TYPE = "type";
    public static final String WORK_FAILURE_TAG = "failed";
    public static final String WORK_SUCCESS_TAG = "success";
    private static final String ADD_WORKOUT_WORKER_TAG = "Worker Tag";
    private WorkoutDAO workoutDAO;
    private AppDatabase database;
    Boolean workSuccess;

    //Worker constructor
    public AddWorkoutWorker(@NonNull Context context,@NonNull WorkerParameters workerParams) {
        super(context,workerParams);
        database = AppDatabase.getInstance(context);
        workoutDAO = database.workoutDAO();
    }

    @NonNull
    @Override
    public Result doWork() {

        //Gets input data
        Data inputData = getInputData();
        String workoutName = inputData.getString(WORK_WORKOUT_NAME);
        String workoutType = inputData.getString(WORK_WORKOUT_TYPE);


        if (workoutName != null && workoutType != null){
            //Inserts item in database through DAO
            Log.d(ADD_WORKOUT_WORKER_TAG,"Worker data passed: "+workoutName + workoutType);
            Workout workout = new Workout(workoutName,workoutType);
            workoutDAO.insertSingleWorkout(workout);
        }else{
            //Returns false if the worker doesn't add the item to the database
            workSuccess = false;
            Data output = new Data.Builder()
                    .putBoolean(WORK_FAILURE_TAG,workSuccess)
                    .build();
            return Result.failure(output);
        }

        //Returns true if the worker adds the item to the database
        workSuccess = true;
        Data output = new Data.Builder()
                .putBoolean(WORK_SUCCESS_TAG,workSuccess)
                .build();

        return Result.success(output);
    }
}

ViewModel.java

public class AddWorkoutViewModel extends AndroidViewModel {

    private static final String WORKOUT_VIEW_MODEL = "Workout View Model";
    private AddWorkoutRepository repository;
    private AddWorkoutWorker worker;
    private WorkManager workManager;
    private Boolean check;
    private LiveData<List<WorkInfo>> workerOutPut;
    //private LiveData<List<Workout>> AllWorkouts;

    public AddWorkoutViewModel(@NonNull Application application) {
        super(application);
        repository = new AddWorkoutRepository(application);
        workManager = WorkManager.getInstance(application);
        workerOutPut = workManager.getWorkInfosByTagLiveData(ADD_WORKOUT_WORKER_QUEUE_TAG);
        //AllWorkouts = repository.getAllWorkouts();
    }


    /*public LiveData<List<Workout>> getWorkoutList(){
        return AllWorkouts;
    }*/

    public LiveData<List<WorkInfo>> checkWorkerStatus(){
        return workerOutPut;
    }

    public void insertData(Workout workout){
        Log.d(WORKOUT_VIEW_MODEL,"View Model Insert Data");
        repository.insertWorkout(workout);
    }
}

活动内部的观察者

//Observes LiveData from WorkManager AddWorkoutWorker to validate if worker functioned correctly
        mAddWorkoutViewModel.checkWorkerStatus().observe(this,new Observer<List<WorkInfo>>() {
            @Override
            public void onChanged(List<WorkInfo> workInfos) {

                if(workInfos.isEmpty() || workInfos == null){
                    Log.d(ADD_WORKOUT_WORKER_EMPTY,"Worker is empty");
                }else{

                    if(workInfos.get(0).getOutputData().getBoolean(WORK_SUCCESS_TAG,false)){

                        //If works do stuff here

                    }else{
                        Toast.makeText(AddWorkoutActivity.this,"Something went wrong. Try again.",Toast.LENGTH_LONG);
                    }

                }

            }
        });

对于那些可能想知道的人。我使用 workInfos.get(0) 因为我们只有一个工人正在检查。我假设如果我们同时有多个工人，我们可以为每个工人制定一个案例。

版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。

相关推荐

导入项目后报错问题
依赖报错 idea导入项目后依赖报错，解决方案：https://blog.csdn.net/weixin_42420249/article/details/81191861 依赖版本报错：更换其他版本 无法下载依赖可参考：https://blog.csdn.net/weixin_42628809/a
idea不能识别yaml文件
使用mybatis plus常见错误
错误1：代码生成器依赖和mybatis依赖冲突 启动项目时报错如下 2021-12-03 13:33:33.927 ERROR 7228 [ main] o.s.b.d.LoggingFailureAnalysisReporter : *************************** APPL
gradle常见问题与错误
错误1：gradle项目控制台输出为乱码 # 解决方案：https://blog.csdn.net/weixin_43501566/article/details/112482302 # 在gradle-wrapper.properties 添加以下内容 org.gradle.jvmargs=-Df
Mybatis Plus传入参数0不起作用
错误还原：在查询的过程中，传入的workType为0时，该条件不起作用 &lt;select id=&quot;xxx&quot;&gt; SELECT di.id, di.name, di.work_type, di.updated... &lt;where&gt; &lt;if test=&qu
linux中make编译源码包失败
报错如下，gcc版本太低 ^ server.c:5346:31: 错误：‘struct redisServer’没有名为‘server_cpulist’的成员 redisSetCpuAffinity(server.server_cpulist); ^ server.c: 在函数‘hasActiveC
微服务启动错误：Command line is too long. Shorten command line for
解决方案1 1、改项目中.idea/workspace.xml配置文件，增加dynamic.classpath参数 2、搜索PropertiesComponent，添加如下 &lt;property name=&quot;dynamic.classpath&quot; value=&quot;tru
vue常见错误
删除根组件app.vue中的默认代码后报错：Module Error (from ./node_modules/eslint-loader/index.js): 解决方案：关闭ESlint代码检测，在项目根目录创建vue.config.js，在文件中添加 module.exports = { lin
spark常见错误
查看spark默认的python版本 [root@master day27]# pyspark /home/software/spark-2.3.4-bin-hadoop2.7/conf/spark-env.sh: line 2: /usr/local/hadoop/bin/hadoop: No s
matplotlib报错：AttributeError: module 'backend_interagg' has no attribute 'FigureCanvas'. Did you mean: 'FigureCanvasAgg'?
使用本地python环境可以成功执行 import pandas as pd import matplotlib.pyplot as plt # 设置字体 plt.rcParams[&#39;font.sans-serif&#39;] = [&#39;SimHei&#39;] # 能正确显示负号 p
gitlab登录失败，报错：This challenge page was accidentally cached by an intermediary and is no longer available.
设置时间 控制面板
后端开发常见错误
错误1：Request method ‘DELETE‘ not supported 错误还原：controller层有一个接口，访问该接口时报错：Request method ‘DELETE‘ not supported 错误原因：没有接收到前端传入的参数，修改为如下 参考 错误2：cannot r
docker常见错误
错误1：启动docker镜像时报错：Error response from daemon: driver failed programming external connectivity on endpoint quirky_allen 解决方法：重启docker -&gt; systemctl r
idea常见错误
错误1：private field ‘xxx‘ is never assigned 按Altʾnter快捷键，选择第2项 参考：https://blog.csdn.net/shi_hong_fei_hei/article/details/88814070 错误2：启动时报错，不能找到主启动类 #
pip安装依赖失败
报错如下，通过源不能下载，最后警告pip需升级版本 Requirement already satisfied: pip in c:\users\ychen\appdata\local\programs\python\python310\lib\site-packages (22.0.4) Coll
maven常见错误
错误1：maven打包报错 错误还原：使用maven打包项目时报错如下 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-resources-plugin:3.2.0:resources (default-resources)
cloud项目中常见错误
错误1：服务调用时报错 服务消费者模块assess通过openFeign调用服务提供者模块hires 如下为服务提供者模块hires的控制层接口 @RestController @RequestMapping(&quot;/hires&quot;) public class FeignControl
springboot常见错误
错误1：运行项目后报如下错误 解决方案 报错2：Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project sb 解决方案：在pom.
springmvc拦截器中使用redisTemplate报空指针异常
参考 错误原因 过滤器或拦截器在生效时，redisTemplate还没有注入 解决方案：在注入容器时就生效 @Component //项目运行时就注入Spring容器 public class RedisBean { @Resource private RedisTemplate&lt;String
vite报错：npm ERR! command C:WINDOWSsystem32cmd.exe /d /s /c C:UsersychenAppDataLocalTempnpx-dde1c848.cmd
使用vite构建项目报错 C:\Users\ychen\work&gt;npm init @vitejs/app @vitejs/create-app is deprecated, use npm init vite instead C:\Users\ychen\AppData\Local\npm-
pythonJavaScriptjavaHTMLPHPreactjsC#AndroidCSSNode.jssqlrpython-3.xMysqLjQueryc++pandasFlutterangularIOSdjangolinuxswifttypescript路由器JSON路由器设置无线路由器h3c华三华三路由器设置华三路由器电脑软件教程arraysdocker软件图文教程Cvue.jslaravelspring-boot