Add support for dynamics workflows to Springboot

Author: Quinn-With-Two-Ns

temporal-spring-boot-autoconfigure/src/main/java/io/temporal/spring/boot/autoconfigure/template/WorkersTemplate.java

@@ -20,15 +20,19 @@
 
 package io.temporal.spring.boot.autoconfigure.template;
 
+import static io.temporal.serviceclient.CheckedExceptionWrapper.wrap;
+
 import com.google.common.base.Preconditions;
 import io.nexusrpc.ServiceDefinition;
 import io.nexusrpc.handler.ServiceImplInstance;
 import io.opentracing.Tracer;
 import io.temporal.client.WorkflowClient;
 import io.temporal.common.Experimental;
+import io.temporal.common.converter.EncodedValues;
 import io.temporal.common.metadata.POJOActivityImplMetadata;
 import io.temporal.common.metadata.POJOWorkflowImplMetadata;
 import io.temporal.common.metadata.POJOWorkflowMethodMetadata;
+import io.temporal.internal.common.env.ReflectionUtils;
 import io.temporal.internal.sync.POJOWorkflowImplementationFactory;
 import io.temporal.spring.boot.ActivityImpl;
 import io.temporal.spring.boot.NexusServiceImpl;
@@ -37,15 +41,11 @@
 import io.temporal.spring.boot.autoconfigure.properties.NamespaceProperties;
 import io.temporal.spring.boot.autoconfigure.properties.WorkerProperties;
 import io.temporal.worker.*;
+import io.temporal.workflow.DynamicWorkflow;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
+import java.lang.reflect.Method;
+import java.util.*;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import org.slf4j.Logger;
@@ -512,6 +512,48 @@ private void configureWorkflowImplementationAutoDiscovery(
 
   @SuppressWarnings("unchecked")
   private <T> void configureWorkflowImplementation(Worker worker, Class<?> clazz) {
+    // Handle dynamic workflows
+    if (DynamicWorkflow.class.isAssignableFrom(clazz)) {
+      try {
+        Method executeMethod = clazz.getMethod("execute", EncodedValues.class);
+        Optional<Constructor<?>> ctor =
+            ReflectionUtils.getWorkflowInitConstructor(
+                clazz, Collections.singletonList(executeMethod));
+        WorkflowImplementationOptions workflowImplementationOptions =
+            new WorkflowImplementationOptionsTemplate(workflowImplementationCustomizer)
+                .createWorkflowImplementationOptions();
+        worker.registerWorkflowImplementationFactory(
+            DynamicWorkflow.class,
+            (encodedValues) -> {
+              if (ctor.isPresent()) {
+                try {
+                  return (DynamicWorkflow) ctor.get().newInstance(encodedValues);
+                } catch (InstantiationException
+                    | IllegalAccessException
+                    | InvocationTargetException e) {
+                  throw wrap(e);
+                }
+              } else {
+                try {
+                  return (DynamicWorkflow) clazz.getDeclaredConstructor().newInstance();
+                } catch (NoSuchMethodException
+                    | InstantiationException
+                    | IllegalAccessException
+                    | InvocationTargetException e) {
+                  // Error to fail workflow task as this can be fixed by a new deployment.
+                  throw new Error(
+                      "Failure instantiating workflow implementation class " + clazz.getName(), e);
+                }
+              }
+            },
+            workflowImplementationOptions);
+        return;
+      } catch (NoSuchMethodException e) {
+        throw new BeanDefinitionValidationException(
+            "Dynamic workflow implementation doesn't have execute method: " + clazz, e);
+      }
+    }
+
     POJOWorkflowImplMetadata workflowMetadata =
         POJOWorkflowImplMetadata.newInstanceForWorkflowFactory(clazz);
     List<POJOWorkflowMethodMetadata> workflowMethods = workflowMetadata.getWorkflowMethods();

temporal-spring-boot-autoconfigure/src/test/java/io/temporal/spring/boot/autoconfigure/AutoDiscoveryByWorkerNameTest.java

@@ -23,6 +23,7 @@
 import io.temporal.api.nexus.v1.Endpoint;
 import io.temporal.client.WorkflowClient;
 import io.temporal.client.WorkflowOptions;
+import io.temporal.client.WorkflowStub;
 import io.temporal.spring.boot.autoconfigure.bytaskqueue.TestWorkflow;
 import io.temporal.testing.TestWorkflowEnvironment;
 import org.junit.jupiter.api.*;
@@ -64,6 +65,12 @@ public void testAutoDiscovery() {
         workflowClient.newWorkflowStub(
             TestWorkflow.class, WorkflowOptions.newBuilder().setTaskQueue("UnitTest").build());
     testWorkflow.execute("nexus");
+
+    WorkflowStub dynamicStub =
+        workflowClient.newUntypedWorkflowStub(
+            "DynamicWorkflow", WorkflowOptions.newBuilder().setTaskQueue("UnitTest").build());
+    dynamicStub.start();
+    Assertions.assertEquals("hello from dynamic workflow", dynamicStub.getResult(String.class));
   }
 
   @ComponentScan(

temporal-spring-boot-autoconfigure/src/test/java/io/temporal/spring/boot/autoconfigure/byworkername/TestDynamicWorkflowImpl.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2022 Temporal Technologies, Inc. All Rights Reserved.
+ *
+ * Copyright (C) 2012-2016 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ *
+ * Modifications copyright (C) 2017 Uber Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this material 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.temporal.spring.boot.autoconfigure.byworkername;
+
+import io.temporal.common.converter.EncodedValues;
+import io.temporal.spring.boot.WorkflowImpl;
+import io.temporal.workflow.DynamicWorkflow;
+
+@WorkflowImpl(workers = "mainWorker")
+public class TestDynamicWorkflowImpl implements DynamicWorkflow {
+  @Override
+  public Object execute(EncodedValues args) {
+    return "hello from dynamic workflow";
+  }
+}