问使用Java/Scala代码获取数据流作业状态

EN

- Using [Jobs endpoint](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/projects.jobs), you can submit a request and it should return the `currentState`. See [currentState](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/projects.jobs#jobstate) to view all states available for the job. This includes JOB\_STATE\_DONE,JOB\_STATE\_RUNNING, JOB\_STATE\_FAILED, etc.
- This can be used for both batch and streaming.
- In Java if I'm not mistaken you can use [Job class and method getCurrentState](https://developers.google.com/resources/api-libraries/documentation/dataflow/v1b3/java/latest/com/google/api/services/dataflow/model/Job.html#getCurrentState--)
- Example:  

- You mentioned that you already retrieved JobMetrics.
- [JobMetrics endpoint](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/JobMetrics) returns lists of [MetricStructuredName objects](https://cloud.google.com/dataflow/docs/reference/rest/v1b3/MetricUpdate). These objects contain the source that generated the metric. You can find your metrics that can be seen on "Steps".
- For example if you have a `ReadFromPubSub` step, you can find the the number of messages that it read. See screenshot below on what the object looks like and what it looks like on the UI.
- You just need to filter out the data properly for you to see the details you need.
- In Java it should be from [JobMetrics class and method getMetrics](https://developers.google.com/resources/api-libraries/documentation/dataflow/v1b3/java/latest/com/google/api/services/dataflow/model/JobMetrics.html#getMetrics--)
- Example (`scalar` contains the value of **"Elements Added"** values are not the same because it is continuously streaming):  
    - ​

- Data freshness cannot be pulled using the Dataflow API.
- The data is created using Cloud Monitoring and if you need this data you need to learn Monitoring API. See [sample codes](https://cloud.google.com/monitoring/docs/samples/monitoring-read-timeseries-simple#monitoring_read_timeseries_simple-java) on how to use the API.
- To view the created metric go to GCP Console > Monitoring > Dashboards >  GCP > Dataflow
- You should see a list of the Dataflow jobs and their metrics.
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