feat: Support registering activities with custom name

sdk-tests/src/test/java/io/dapr/it/testcontainers/workflows/DaprWorkflowsIT.java

@@ -147,6 +147,27 @@ public void testSuspendAndResumeWorkflows() throws Exception {
 
   }
 
+  @Test
+  public void testNamedActivitiesWorkflows() throws Exception {
+    TestWorkflowPayload payload = new TestWorkflowPayload(new ArrayList<>());
+    String instanceId = workflowClient.scheduleNewWorkflow(TestNamedActivitiesWorkflow.class, payload);
+
+    workflowClient.waitForInstanceStart(instanceId, Duration.ofSeconds(10), false);
+
+    Duration timeout = Duration.ofSeconds(10);
+    WorkflowInstanceStatus workflowStatus = workflowClient.waitForInstanceCompletion(instanceId, timeout, true);
+
+    assertNotNull(workflowStatus);
+
+    TestWorkflowPayload workflowOutput = deserialize(workflowStatus.getSerializedOutput());
+
+    assertEquals(3, workflowOutput.getPayloads().size());
+    assertEquals("First Activity", workflowOutput.getPayloads().get(0));
+    assertEquals("First Activity", workflowOutput.getPayloads().get(1));
+    assertEquals("Second Activity", workflowOutput.getPayloads().get(2));
+
+    assertEquals(instanceId, workflowOutput.getWorkflowId());
+  }
 
   private TestWorkflowPayload deserialize(String value) throws JsonProcessingException {
     return OBJECT_MAPPER.readValue(value, TestWorkflowPayload.class);

sdk-tests/src/test/java/io/dapr/it/testcontainers/workflows/TestNamedActivitiesWorkflow.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2025 The Dapr Authors
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package io.dapr.it.testcontainers.workflows;
+
+import io.dapr.workflows.Workflow;
+import io.dapr.workflows.WorkflowStub;
+import org.slf4j.Logger;
+
+public class TestNamedActivitiesWorkflow implements Workflow {
+
+  @Override
+  public WorkflowStub create() {
+    return ctx -> {
+      Logger logger = ctx.getLogger();
+      String instanceId = ctx.getInstanceId();
+      logger.info("Starting Workflow: " + ctx.getName());
+      logger.info("Instance ID: " + instanceId);
+      logger.info("Current Orchestration Time: " + ctx.getCurrentInstant());
+
+      TestWorkflowPayload workflowPayload = ctx.getInput(TestWorkflowPayload.class);
+      workflowPayload.setWorkflowId(instanceId);
+
+      var payloadAfterA = ctx.callActivity("a", workflowPayload, TestWorkflowPayload.class).await();
+
+      var payloadAfterB = ctx.callActivity("b", payloadAfterA, TestWorkflowPayload.class).await();
+
+      var payloadAfteC = ctx.callActivity("c", payloadAfterB, TestWorkflowPayload.class)
+          .await();
+
+      ctx.complete(payloadAfteC);
+    };
+  }
+
+}

sdk-tests/src/test/java/io/dapr/it/testcontainers/workflows/TestWorkflowsConfiguration.java

@@ -56,8 +56,14 @@ public WorkflowRuntimeBuilder workflowRuntimeBuilder(
     WorkflowRuntimeBuilder builder = new WorkflowRuntimeBuilder(new Properties(overrides));
 
     builder.registerWorkflow(TestWorkflow.class);
+    builder.registerWorkflow(TestNamedActivitiesWorkflow.class);
+
     builder.registerActivity(FirstActivity.class);
     builder.registerActivity(SecondActivity.class);
+    builder.registerActivity("a",FirstActivity.class);
+    builder.registerActivity("b",FirstActivity.class);
+    builder.registerActivity("c", new SecondActivity());
+
 
     return builder;
   }

sdk-workflows/src/main/java/io/dapr/workflows/runtime/WorkflowActivityClassWrapper.java

@@ -30,19 +30,28 @@
   /**
    * Constructor for WorkflowActivityWrapper.
    *
+   * @param name  Name of the activity to wrap.
    * @param clazz Class of the activity to wrap.
    */
-  public WorkflowActivityClassWrapper(Class<T> clazz) {
-    this.name = clazz.getCanonicalName();
+  public WorkflowActivityClassWrapper(String name, Class<T> clazz) {
+    this.name = name;
     try {
       this.activityConstructor = clazz.getDeclaredConstructor();
     } catch (NoSuchMethodException e) {
       throw new RuntimeException(
-          String.format("No constructor found for activity class '%s'.", this.name), e
-      );
+          String.format("No constructor found for activity class '%s'.", this.name), e);
     }
   }
 
+  /**
+   * Constructor for WorkflowActivityWrapper.
+   *
+   * @param clazz Class of the activity to wrap.
+   */
+  public WorkflowActivityClassWrapper(Class<T> clazz) {
+    this(clazz.getCanonicalName(), clazz);
+  }
+
   @Override
   public String getName() {
     return name;
@@ -53,13 +62,12 @@
     return ctx -> {
       Object result;
       T activity;
-      
+
       try {
         activity = this.activityConstructor.newInstance();
       } catch (InstantiationException | IllegalAccessException | InvocationTargetException e) {
         throw new RuntimeException(
-            String.format("Unable to instantiate instance of activity class '%s'", this.name), e
-        );
+            String.format("Unable to instantiate instance of activity class '%s'", this.name), e);
       }
 
       result = activity.run(new DefaultWorkflowActivityContext(ctx));

sdk-workflows/src/main/java/io/dapr/workflows/runtime/WorkflowActivityInstanceWrapper.java

@@ -27,13 +27,23 @@ public class WorkflowActivityInstanceWrapper<T extends WorkflowActivity> impleme
   /**
    * Constructor for WorkflowActivityWrapper.
    *
+   * @param name     Name of the activity to wrap.
    * @param instance Instance of the activity to wrap.
    */
-  public WorkflowActivityInstanceWrapper(T instance) {
-    this.name = instance.getClass().getCanonicalName();
+  public WorkflowActivityInstanceWrapper(String name, T instance) {
+    this.name = name;
     this.activity = instance;
   }
 
+  /**
+   * Constructor for WorkflowActivityWrapper.
+   *
+   * @param instance Instance of the activity to wrap.
+   */
+  public WorkflowActivityInstanceWrapper(T instance) {
+    this(instance.getClass().getCanonicalName(), instance);
+  }
+
   @Override
   public String getName() {
     return name;

sdk-workflows/src/main/java/io/dapr/workflows/runtime/WorkflowRuntimeBuilder.java

@@ -147,11 +147,23 @@ public <T extends Workflow> WorkflowRuntimeBuilder registerWorkflow(T instance)
    * @return the WorkflowRuntimeBuilder
    */
   public <T extends WorkflowActivity> WorkflowRuntimeBuilder registerActivity(Class<T> clazz) {
-    this.builder.addActivity(new WorkflowActivityClassWrapper<>(clazz));
-    this.activitySet.add(clazz.getCanonicalName());
-    this.activities.add(clazz.getSimpleName());
+    return registerActivity(clazz.getCanonicalName(), clazz);
+  }
 
-    this.logger.info("Registered Activity: {}", clazz.getSimpleName());
+  /**
+   * Registers an Activity object.
+   *
+   * @param <T>   any WorkflowActivity type
+   * @param name Name of the activity to register.
+   * @param clazz Class of the activity to register.
+   * @return the WorkflowRuntimeBuilder
+   */
+  public <T extends WorkflowActivity> WorkflowRuntimeBuilder registerActivity(String name, Class<T> clazz) {
+    this.builder.addActivity(new WorkflowActivityClassWrapper<>(name, clazz));
+    this.activitySet.add(name);
+    this.activities.add(name);
+
+    this.logger.info("Registered Activity: {}", name);
 
     return this;
   }
@@ -164,13 +176,23 @@ public <T extends WorkflowActivity> WorkflowRuntimeBuilder registerActivity(Clas
    * @return the WorkflowRuntimeBuilder
    */
   public <T extends WorkflowActivity> WorkflowRuntimeBuilder registerActivity(T instance) {
-    Class<T> clazz = (Class<T>) instance.getClass();
+    return this.registerActivity(instance.getClass().getCanonicalName(), instance);
+  }
 
-    this.builder.addActivity(new WorkflowActivityInstanceWrapper<>(instance));
-    this.activitySet.add(clazz.getCanonicalName());
-    this.activities.add(clazz.getSimpleName());
+  /**
+   * Registers an Activity object.
+   *
+   * @param <T>   any WorkflowActivity type
+   * @param name Name of the activity to register.
+   * @param instance the class instance being registered
+   * @return the WorkflowRuntimeBuilder
+   */
+  public <T extends WorkflowActivity> WorkflowRuntimeBuilder registerActivity(String name, T instance) {
+    this.builder.addActivity(new WorkflowActivityInstanceWrapper<>(name, instance));
+    this.activitySet.add(name);
+    this.activities.add(name);
 
-    this.logger.info("Registered Activity: {}", clazz.getSimpleName());
+    this.logger.info("Registered Activity: {}", name);
 
     return this;
   }

sdk-workflows/src/test/java/io/dapr/workflows/runtime/WorkflowActivityClassWrapperTest.java

@@ -22,7 +22,7 @@ public Object run(WorkflowActivityContext ctx) {
 
   @Test
   public void getName() {
-    WorkflowActivityClassWrapper<TestActivity> wrapper = new WorkflowActivityClassWrapper<>(TestActivity.class);
+    WorkflowActivityClassWrapper<TestActivity> wrapper = new WorkflowActivityClassWrapper<>( TestActivity.class);
 
     assertEquals(
         "io.dapr.workflows.runtime.WorkflowActivityClassWrapperTest.TestActivity",

sdk-workflows/src/test/java/io/dapr/workflows/runtime/WorkflowRuntimeBuilderTest.java

@@ -94,6 +94,6 @@ public void loggingOutputTest() {
         .info(eq("Registered Workflow: {}"), eq("TestWorkflow"));
 
     verify(testLogger, times(1))
-        .info(eq("Registered Activity: {}"), eq("TestActivity"));
+        .info(eq("Registered Activity: {}"), eq( "io.dapr.workflows.runtime.WorkflowRuntimeBuilderTest.TestActivity"));
   }
 }