Cancel Workflow Via API

Community Support
1

Hi all, I’m new to Temporal and working with the Java SDK to implement signals and querying into our existing workflows. To put it simply, I am looking for a way to use a string to query a workflow ID and then use that workflow object to send signals/queries/etc. Is there any way to do this using the Java SDK? The docs don’t seem to mention anything about working with workflows in the SDK after they are instantiated.

2

I would recommend using your business identifier as a workflow ID. Then you don’t need to perform any lookups to perform operations on the workflows by their business id. In Java SDK you assign workflow id through WorkflowOptions:

    WorkflowOptions workflowOptions =
        WorkflowOptions.newBuilder().setTaskQueue(TASK_QUEUE).setWorkflowId("BusinessId").build();
    GreetingWorkflow workflow = client.newWorkflowStub(GreetingWorkflow.class, workflowOptions);
3

Thanks for the reply, this could possibly help but I am wondering how one would look up a workflow from within the SDK. Is it only possible to send signals/queries from the command line? Or is there a way to use the SDK to get existing workflows?

4

Both UI and CLI use the same gRPC API SDKs use. So everything is possible through them is possible through SDKs.

Here are signal and query Java samples.

I am wondering how one would look up a workflow from within the SDK.

As I mentioned the best way is by using the workflow id that you assigned. The other option is to use list APIs:

WorkflowServiceStubs service = WorkflowServiceStubs.newInstance(options);
service.blockingStub().listWorkflowExecutions(...);
5

Thanks for your help! This should be perfect