SpringBoot - Sync Update Example (#490)

* SpringBoot - Sync Update Example

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

* fix text

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

* update - move local activity calls from update handler

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

* update

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

---------

Signed-off-by: Tihomir Surdilovic <tihomir@temporal.io>

Author: tsurdilo

README.md

@@ -141,4 +141,5 @@ See the README.md file in each main sample directory for cut/paste Gradle comman
 More info on each sample:
 - [**Hello**](/springboot/src/main/java/io/temporal/samples/springboot/hello): Invoke simple "Hello" workflow from a GET endpoint
 - [**SDK Metrics**](/springboot/src/main/java/io/temporal/samples/springboot/metrics): Learn how to set up SDK Metrics
+- [**Synchronous Update**](/springboot/src/main/java/io/temporal/samples/springboot/update): Learn how to use Synchronous Update feature with this purchase sample
 

springboot/build.gradle

@@ -4,8 +4,10 @@ dependencies {
     implementation "org.springframework.boot:spring-boot-starter-web"
     implementation "org.springframework.boot:spring-boot-starter-thymeleaf"
     implementation "org.springframework.boot:spring-boot-starter-actuator"
+    implementation "org.springframework.boot:spring-boot-starter-data-jpa"
     implementation "io.temporal:temporal-spring-boot-starter-alpha:$javaSDKVersion"
     runtimeOnly "io.micrometer:micrometer-registry-prometheus"
+    runtimeOnly "com.h2database:h2"
     testImplementation "org.springframework.boot:spring-boot-starter-test"
     dependencies {
         errorproneJavac('com.google.errorprone:javac:9+181-r4173-1')

springboot/src/main/java/io/temporal/samples/springboot/SamplesController.java

@@ -19,10 +19,16 @@
 
 package io.temporal.samples.springboot;
 
+import io.grpc.StatusRuntimeException;
 import io.temporal.client.WorkflowClient;
 import io.temporal.client.WorkflowOptions;
+import io.temporal.client.WorkflowStub;
+import io.temporal.client.WorkflowUpdateException;
 import io.temporal.samples.springboot.hello.HelloWorkflow;
 import io.temporal.samples.springboot.hello.model.Person;
+import io.temporal.samples.springboot.update.PurchaseWorkflow;
+import io.temporal.samples.springboot.update.model.ProductRepository;
+import io.temporal.samples.springboot.update.model.Purchase;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
@@ -36,6 +42,8 @@ public class SamplesController {
 
   @Autowired WorkflowClient client;
 
+  @Autowired ProductRepository productRepository;
+
   @GetMapping("/hello")
   public String hello(Model model) {
     model.addAttribute("sample", "Say Hello");
@@ -64,4 +72,55 @@ public String metrics(Model model) {
     model.addAttribute("sample", "SDK Metrics");
     return "metrics";
   }
+
+  @GetMapping("/update")
+  public String update(Model model) {
+    model.addAttribute("sample", "Synchronous Update");
+    model.addAttribute("products", productRepository.findAll());
+    return "update";
+  }
+
+  @GetMapping("/update/inventory")
+  public String updateInventory(Model model) {
+    model.addAttribute("products", productRepository.findAll());
+    return "update :: inventory";
+  }
+
+  @PostMapping(
+      value = "/update/purchase",
+      consumes = {MediaType.APPLICATION_JSON_VALUE},
+      produces = {MediaType.TEXT_HTML_VALUE})
+  ResponseEntity purchase(@RequestBody Purchase purchase) {
+    PurchaseWorkflow workflow =
+        client.newWorkflowStub(
+            PurchaseWorkflow.class,
+            WorkflowOptions.newBuilder()
+                .setTaskQueue("UpdateSampleTaskQueue")
+                .setWorkflowId("NewPurchase")
+                .build());
+    WorkflowClient.start(workflow::start);
+
+    // send update
+    try {
+      boolean isValidPurchase = workflow.makePurchase(purchase);
+      // for sample send exit to workflow exec and wait till it completes
+      workflow.exit();
+      WorkflowStub.fromTyped(workflow).getResult(Void.class);
+      if (!isValidPurchase) {
+        return new ResponseEntity("\"Invalid purchase\"", HttpStatus.NOT_FOUND);
+      }
+      return new ResponseEntity("\"" + "Purchase successful" + "\"", HttpStatus.OK);
+    } catch (WorkflowUpdateException | StatusRuntimeException e) {
+      // for sample send exit to workflow exec and wait till it completes
+      workflow.exit();
+      WorkflowStub.fromTyped(workflow).getResult(Void.class);
+
+      String message = e.getMessage();
+      if (e instanceof WorkflowUpdateException) {
+        message = e.getCause().getMessage();
+      }
+
+      return new ResponseEntity("\"" + message + "\"", HttpStatus.NOT_FOUND);
+    }
+  }
 }

springboot/src/main/java/io/temporal/samples/springboot/hello/model/Person.java

@@ -24,7 +24,6 @@ public class Person {
   private String lastName;
 
   public Person() {}
-  ;
 
   public Person(String firstName, String lastName) {
     this.firstName = firstName;

springboot/src/main/java/io/temporal/samples/springboot/update/ProductNotAvailableForAmountException.java

@@ -0,0 +1,26 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 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 file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.samples.springboot.update;
+
+public class ProductNotAvailableForAmountException extends Exception {
+  public ProductNotAvailableForAmountException(String message) {
+    super(message);
+  }
+}

springboot/src/main/java/io/temporal/samples/springboot/update/PurchaseActivities.java

@@ -0,0 +1,30 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 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 file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.samples.springboot.update;
+
+import io.temporal.activity.ActivityInterface;
+import io.temporal.samples.springboot.update.model.Purchase;
+
+@ActivityInterface
+public interface PurchaseActivities {
+  boolean isProductInStockForPurchase(Purchase purchase);
+
+  boolean makePurchase(Purchase purchase);
+}

springboot/src/main/java/io/temporal/samples/springboot/update/PurchaseActivitiesImpl.java

@@ -0,0 +1,59 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 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 file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.samples.springboot.update;
+
+import io.temporal.samples.springboot.update.model.Product;
+import io.temporal.samples.springboot.update.model.ProductRepository;
+import io.temporal.samples.springboot.update.model.Purchase;
+import io.temporal.spring.boot.ActivityImpl;
+import java.util.Optional;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+@Component
+@ActivityImpl(taskQueues = "UpdateSampleTaskQueue")
+public class PurchaseActivitiesImpl implements PurchaseActivities {
+  @Autowired ProductRepository productRepository;
+
+  @Override
+  public boolean isProductInStockForPurchase(Purchase purchase) {
+    Product product = getProductFor(purchase);
+    return product != null && product.getStock() >= purchase.getAmount();
+  }
+
+  @Override
+  public boolean makePurchase(Purchase purchase) {
+    Product product = getProductFor(purchase);
+    if (product != null) {
+      product.setStock(product.getStock() - purchase.getAmount());
+      productRepository.save(product);
+      return true;
+    }
+    return false;
+  }
+
+  private Product getProductFor(Purchase purchase) {
+    Optional<Product> productOptional = productRepository.findById(purchase.getProduct());
+    if (productOptional.isPresent()) {
+      return productOptional.get();
+    }
+    return null;
+  }
+}

springboot/src/main/java/io/temporal/samples/springboot/update/PurchaseWorkflow.java

@@ -0,0 +1,38 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 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 file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.samples.springboot.update;
+
+import io.temporal.samples.springboot.update.model.Purchase;
+import io.temporal.workflow.*;
+
+@WorkflowInterface
+public interface PurchaseWorkflow {
+  @WorkflowMethod
+  void start();
+
+  @UpdateMethod
+  boolean makePurchase(Purchase purchase);
+
+  @UpdateValidatorMethod(updateName = "makePurchase")
+  void makePurchaseValidator(Purchase purchase);
+
+  @SignalMethod
+  void exit();
+}

springboot/src/main/java/io/temporal/samples/springboot/update/PurchaseWorkflowImpl.java

@@ -0,0 +1,82 @@
+/*
+ *  Copyright (c) 2020 Temporal Technologies, Inc. All Rights Reserved
+ *
+ *  Copyright 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 file except in compliance with the License. A copy of the License is
+ *  located at
+ *
+ *  http://aws.amazon.com/apache2.0
+ *
+ *  or in the "license" file accompanying this file. This file 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.samples.springboot.update;
+
+import io.temporal.activity.LocalActivityOptions;
+import io.temporal.failure.ApplicationFailure;
+import io.temporal.samples.springboot.update.model.Purchase;
+import io.temporal.spring.boot.WorkflowImpl;
+import io.temporal.workflow.Workflow;
+import java.time.Duration;
+
+@WorkflowImpl(taskQueues = "UpdateSampleTaskQueue")
+public class PurchaseWorkflowImpl implements PurchaseWorkflow {
+
+  private boolean newPurchase = false;
+  private boolean exit = false;
+  private PurchaseActivities activities =
+      Workflow.newLocalActivityStub(
+          PurchaseActivities.class,
+          LocalActivityOptions.newBuilder().setStartToCloseTimeout(Duration.ofSeconds(2)).build());
+
+  @Override
+  public void start() {
+    // for sake of sample we only wait for a single purchase or exit signal
+    Workflow.await(() -> newPurchase || exit);
+  }
+
+  @Override
+  public boolean makePurchase(Purchase purchase) {
+
+    if (!activities.isProductInStockForPurchase(purchase)) {
+      throw ApplicationFailure.newFailure(
+          "Product "
+              + purchase.getProduct()
+              + " is not in stock for amount "
+              + purchase.getAmount(),
+          ProductNotAvailableForAmountException.class.getName(),
+          purchase);
+    }
+
+    return activities.makePurchase(purchase);
+  }
+
+  @Override
+  public void makePurchaseValidator(Purchase purchase) {
+    // Not allowed to change workflow state inside validator
+    // So invocations of (local) activities is prohibited
+    // We can validate the purchase with some business logic here
+
+    // Assume we have some max inventory amount for single item set to 100
+    if (purchase == null || (purchase.getAmount() < 0 || purchase.getAmount() > 100)) {
+      throw new IllegalArgumentException(
+          "Invalid Product or amount (Product id:"
+              + purchase.getProduct()
+              + ", amount"
+              + purchase.getAmount()
+              + ")");
+    }
+  }
+
+  @Override
+  public void exit() {
+    this.exit = true;
+  }
+}

springboot/src/main/java/io/temporal/samples/springboot/update/README.md

@@ -0,0 +1,35 @@
+# SpringBoot Synchronous Update Sample
+
+1. Start SpringBoot from main samples repo directory:
+
+       ./gradlew bootRun
+
+2. In your browser navigate to:
+
+       http://localhost:3030/update
+
+Pick one of the fishing items you want to purchase from the inventory drop down list.
+Next pick the amount of this item you want to purchase. 
+The inventory is presented in the table below the form.
+For each item you can see the current availble stock count.
+Try first picking an item and then an amount that is less or equal to the items in 
+inventory. You will see that the purchase goes through and the inventory table is updated
+dynamically.
+
+Now try to pick and item and amount that is greater than what's in our inventory.
+You will see that the update fails and you see the "Unable to perform purchase" 
+message that shows the underlying "ProductNotAvailableForAmountException" exception
+raised in the update handler. 
+
+Updating our inventory is done via local activities. The check if item and amount 
+of the fishing item you want to purchase is in inventory is also done by local 
+activity.
+
+## Note
+Make sure that you enable the synchronous update feature on your Temporal cluster.
+This can be done in dynamic config with
+
+        frontend.enableUpdateWorkflowExecution:
+           - value: true
+
+If you don't have this enabled you will see error shown when you try to make any purchase.