Example for tasks interaction

Author: antmendoza

core/src/main/java/io/temporal/samples/asyncchild/ParentWorkflowImpl.java

@@ -25,27 +25,40 @@
 import io.temporal.workflow.ChildWorkflowOptions;
 import io.temporal.workflow.Promise;
 import io.temporal.workflow.Workflow;
+import java.util.ArrayList;
+import java.util.List;
 
 public class ParentWorkflowImpl implements ParentWorkflow {
   @Override
   public WorkflowExecution executeParent() {
 
-    // We set the parentClosePolicy to "Abandon"
-    // This will allow child workflow to continue execution after parent completes
-    ChildWorkflowOptions childWorkflowOptions =
-        ChildWorkflowOptions.newBuilder()
-            .setWorkflowId("childWorkflow")
-            .setParentClosePolicy(ParentClosePolicy.PARENT_CLOSE_POLICY_ABANDON)
-            .build();
-
-    // Get the child workflow stub
-    ChildWorkflow child = Workflow.newChildWorkflowStub(ChildWorkflow.class, childWorkflowOptions);
-    // Start the child workflow async
-    Async.function(child::executeChild);
-    // Get the child workflow execution promise
-    Promise<WorkflowExecution> childExecution = Workflow.getWorkflowExecution(child);
-    // Call .get on the promise. This will block until the child workflow starts execution (or start
-    // fails)
-    return childExecution.get();
+    final List<Promise<WorkflowExecution>> promises = new ArrayList<>();
+
+    for (int i = 0; i < 1000; i++) {
+      // We set the parentClosePolicy to "Abandon"
+      // This will allow child workflow to continue execution after parent completes
+      ChildWorkflowOptions childWorkflowOptions =
+          ChildWorkflowOptions.newBuilder()
+              .setWorkflowId("childWorkflow" + Math.random())
+              .setParentClosePolicy(ParentClosePolicy.PARENT_CLOSE_POLICY_ABANDON)
+              .build();
+
+      // Get the child workflow stub
+      ChildWorkflow child =
+          Workflow.newChildWorkflowStub(ChildWorkflow.class, childWorkflowOptions);
+      // Start the child workflow async
+      Async.function(child::executeChild);
+      // Get the child workflow execution promise
+      Promise<WorkflowExecution> childExecution = Workflow.getWorkflowExecution(child);
+      // Call .get on the promise. This will block until the child workflow starts execution (or
+      // start
+      // fails)
+
+      promises.add(childExecution);
+    }
+
+    Promise.allOf(promises).get();
+
+    return promises.get(0).get();
   }
 }

core/src/main/java/io/temporal/samples/hello/HelloActivity.java

@@ -23,6 +23,7 @@
 import io.temporal.activity.ActivityMethod;
 import io.temporal.activity.ActivityOptions;
 import io.temporal.client.WorkflowClient;
+import io.temporal.client.WorkflowOptions;
 import io.temporal.serviceclient.WorkflowServiceStubs;
 import io.temporal.worker.Worker;
 import io.temporal.worker.WorkerFactory;
@@ -78,7 +79,7 @@ public interface GreetingActivities {
 
     // Define your activity method which can be called during workflow execution
     @ActivityMethod(name = "greet")
-    int composeGreeting(String greeting, String name);
+    String composeGreeting(String greeting, String name);
   }
 
   // Define the workflow implementation which implements our getGreeting workflow method.
@@ -102,12 +103,7 @@ public static class GreetingWorkflowImpl implements GreetingWorkflow {
     @Override
     public String getGreeting(String name) {
       // This is a blocking call that returns only after the activity has completed.
-
-      activities.composeGreeting("Hello", name);
-
-      Workflow.sleep(Duration.ofSeconds(20));
-
-      return "hello";
+      return activities.composeGreeting("Hello", name);
     }
   }
 
@@ -116,10 +112,9 @@ static class GreetingActivitiesImpl implements GreetingActivities {
     private static final Logger log = LoggerFactory.getLogger(GreetingActivitiesImpl.class);
 
     @Override
-    public int composeGreeting(String greeting, String name) {
+    public String composeGreeting(String greeting, String name) {
       log.info("Composing greeting...");
-
-      return 1;
+      return greeting + " " + name + "!";
     }
   }
 
@@ -166,5 +161,27 @@ public static void main(String[] args) {
      * The started workers then start polling for workflows and activities.
      */
     factory.start();
+
+    // Create the workflow client stub. It is used to start our workflow execution.
+    GreetingWorkflow workflow =
+        client.newWorkflowStub(
+            GreetingWorkflow.class,
+            WorkflowOptions.newBuilder()
+                .setWorkflowId(WORKFLOW_ID)
+                .setTaskQueue(TASK_QUEUE)
+                .build());
+
+    /*
+     * Execute our workflow and wait for it to complete. The call to our getGreeting method is
+     * synchronous.
+     *
+     * See {@link io.temporal.samples.hello.HelloSignal} for an example of starting workflow
+     * without waiting synchronously for its result.
+     */
+    String greeting = workflow.getGreeting("World");
+
+    // Display workflow execution results
+    System.out.println(greeting);
+    System.exit(0);
   }
 }