eugenp · xaeldung · Sep 22, 2025 · Jan 14, 2025 · Jan 15, 2025 · Jan 16, 2025
diff --git a/saas-modules/pom.xml b/saas-modules/pom.xml
@@ -25,6 +25,7 @@
         <module>twilio</module>
         <module>twilio-whatsapp</module>
         <module>twitter4j</module>
+        <module>temporal</module>
     </modules>
 
     <build>

diff --git a/saas-modules/temporal/pom.xml b/saas-modules/temporal/pom.xml
@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>temporal</artifactId>
+    <version>1.0</version>
+    <name>temporal</name>
+    <description>Temporal Workflow Engine Tutorial</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>saas-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>io.temporal</groupId>
+            <artifactId>temporal-sdk</artifactId>
+            <version>${temporal.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>io.temporal</groupId>
+            <artifactId>temporal-testing</artifactId>
+            <version>${temporal.version}</version>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${maven-surefire-plugin.version}</version>
+                <configuration>
+                    <argLine>
+                        --add-opens java.base/java.lang=ALL-UNNAMED
+                    </argLine>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <temporal.version>1.31.0</temporal.version>
+    </properties>
+
+</project>
diff --git a/...-modules/temporal/src/main/java/com/baeldung/temporal/worker/TemporalWorkerRegistrar.java b/...-modules/temporal/src/main/java/com/baeldung/temporal/worker/TemporalWorkerRegistrar.java
@@ -0,0 +1,10 @@
+package com.baeldung.temporal.worker;
+
+import io.temporal.worker.Worker;
+
+/**
+ * Interface for registering Workflows and Activities to a Temporal Worker.
+ */
+public interface TemporalWorkerRegistrar {
+    void register(Worker worker);
+}
diff --git a/saas-modules/temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflow.java b/saas-modules/temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflow.java
@@ -0,0 +1,10 @@
+package com.baeldung.temporal.workflows.hello;
+
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+
+@WorkflowInterface
+public interface HelloWorkflow {
+    @WorkflowMethod
+    String hello(String person);
+}
diff --git a/...emporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowApplication.java b/...emporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowApplication.java
@@ -0,0 +1,29 @@
+package com.baeldung.temporal.workflows.hello;
+
+import io.temporal.client.WorkflowClient;
+import io.temporal.serviceclient.WorkflowServiceStubs;
+import io.temporal.worker.Worker;
+import io.temporal.worker.WorkerFactory;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class HelloWorkflowApplication {
+
+    private static final String QUEUE_NAME = "say-hello-queue";
+    private static final Logger log = LoggerFactory.getLogger(HelloWorkflowApplication.class);
+
+    public static void main(String[] args) {
+
+        log.info("Creating worker...");
+        var service = WorkflowServiceStubs.newLocalServiceStubs();
+        var client = WorkflowClient.newInstance(service);
+        var factory = WorkerFactory.newInstance(client);
+        var worker = factory.newWorker(QUEUE_NAME);
+
+        log.info("Registering workflows and activities...");
+        HelloWorkflowRegistrar.newInstance().register(worker);
+
+        log.info("Starting worker...");
+        factory.start();
+    }
+}
diff --git a/...dules/temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowImpl.java b/...dules/temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowImpl.java
@@ -0,0 +1,22 @@
+package com.baeldung.temporal.workflows.hello;
+
+import com.baeldung.temporal.workflows.hello.activities.SayHelloActivity;
+import io.temporal.activity.ActivityOptions;
+import io.temporal.workflow.Workflow;
+
+import java.time.Duration;
+
+public class HelloWorkflowImpl implements HelloWorkflow {
+
+    private final SayHelloActivity activity = Workflow.newActivityStub(
+      SayHelloActivity.class,
+      ActivityOptions.newBuilder()
+        .setStartToCloseTimeout(Duration.ofSeconds(10))
+        .build()
+    );
+
+    @Override
+    public String hello(String person) {
+        return activity.sayHello(person);
+    }
+}
diff --git a/.../temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowRegistrar.java b/.../temporal/src/main/java/com/baeldung/temporal/workflows/hello/HelloWorkflowRegistrar.java
@@ -0,0 +1,20 @@
+package com.baeldung.temporal.workflows.hello;
+
+import com.baeldung.temporal.worker.TemporalWorkerRegistrar;
+import com.baeldung.temporal.workflows.hello.activities.SayHelloActivityImpl;
+import io.temporal.worker.Worker;
+
+public class HelloWorkflowRegistrar implements TemporalWorkerRegistrar {
+
+    private HelloWorkflowRegistrar() {}
+
+    @Override
+    public void register(Worker worker) {
+        worker.registerWorkflowImplementationTypes(HelloWorkflowImpl.class);
+        worker.registerActivitiesImplementations(new SayHelloActivityImpl());
+    }
+
+    public static HelloWorkflowRegistrar newInstance() {
+        return new HelloWorkflowRegistrar();
+    }
+}
diff --git a/...oral/src/main/java/com/baeldung/temporal/workflows/hello/activities/SayHelloActivity.java b/...oral/src/main/java/com/baeldung/temporal/workflows/hello/activities/SayHelloActivity.java
@@ -0,0 +1,10 @@
+package com.baeldung.temporal.workflows.hello.activities;
+
+import io.temporal.activity.ActivityInterface;
+import io.temporal.activity.ActivityMethod;
+
+@ActivityInterface
+public interface SayHelloActivity {
+    @ActivityMethod
+    String sayHello(String person);
+}
diff --git a/.../src/main/java/com/baeldung/temporal/workflows/hello/activities/SayHelloActivityImpl.java b/.../src/main/java/com/baeldung/temporal/workflows/hello/activities/SayHelloActivityImpl.java
@@ -0,0 +1,14 @@
+package com.baeldung.temporal.workflows.hello.activities;
+
+import io.temporal.activity.Activity;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class SayHelloActivityImpl implements SayHelloActivity {
+    private static final Logger log = LoggerFactory.getLogger(SayHelloActivityImpl.class);
+
+    public String sayHello(String person) {
+        log.info("Saying hello to {}", person);
+        return "Hello, " + person;
+    }
+}
diff --git a/...emporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloV2WorkerRegistrar.java b/...emporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloV2WorkerRegistrar.java
@@ -0,0 +1,22 @@
+package com.baeldung.temporal.workflows.hellov2;
+
+import com.baeldung.temporal.worker.TemporalWorkerRegistrar;
+import com.baeldung.temporal.workflows.hellov2.activities.HelloV2ActivitiesImpl;
+import io.temporal.worker.Worker;
+
+public class HelloV2WorkerRegistrar implements TemporalWorkerRegistrar {
+
+
+    private HelloV2WorkerRegistrar() {
+    }
+
+    @Override
+    public void register(Worker worker) {
+        worker.registerWorkflowImplementationTypes(HelloWorkflowV2Impl.class);
+        worker.registerActivitiesImplementations(new HelloV2ActivitiesImpl());
+    }
+
+    public static HelloV2WorkerRegistrar newInstance() {
+        return new HelloV2WorkerRegistrar();
+    }
+}
diff --git a/...dules/temporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloWorkflowV2.java b/...dules/temporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloWorkflowV2.java
@@ -0,0 +1,10 @@
+package com.baeldung.temporal.workflows.hellov2;
+
+import io.temporal.workflow.WorkflowInterface;
+import io.temporal.workflow.WorkflowMethod;
+
+@WorkflowInterface
+public interface HelloWorkflowV2 {
+    @WorkflowMethod
+    String hello(String person);
+}
diff --git a/...s/temporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloWorkflowV2Impl.java b/...s/temporal/src/main/java/com/baeldung/temporal/workflows/hellov2/HelloWorkflowV2Impl.java
@@ -0,0 +1,45 @@
+package com.baeldung.temporal.workflows.hellov2;
+
+import com.baeldung.temporal.workflows.hellov2.activities.HelloV2Activities;
+import io.temporal.activity.ActivityOptions;
+import io.temporal.common.RetryOptions;
+import io.temporal.workflow.Workflow;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.time.Duration;
+
+public class HelloWorkflowV2Impl implements HelloWorkflowV2 {
+
+    private static final Logger log = LoggerFactory.getLogger(HelloWorkflowV2Impl.class);
+
+
+    private final HelloV2Activities activity = Workflow.newActivityStub(
+      HelloV2Activities.class,
+      ActivityOptions.newBuilder()
+        .setStartToCloseTimeout(Duration.ofSeconds(10))
+        .setRetryOptions(RetryOptions.newBuilder()
+          .setMaximumAttempts(3)
+          .setInitialInterval(Duration.ofSeconds(1))
+          .build())
+        .build()
+    );
+
+
+    @Override
+    public String hello(String person) {
+
+        var info = Workflow.getInfo();
+
+        log.info("Running workflow for person {}: id={}, attempt={}",
+          person,
+          info.getWorkflowId(),
+          info.getAttempt());
+
+        var step1result = activity.sayHello(person);
+        var step2result = activity.sayGoodbye(person);
+
+        return "Workflow OK";
+    }
+
+}
diff --git a/...l/src/main/java/com/baeldung/temporal/workflows/hellov2/activities/HelloV2Activities.java b/...l/src/main/java/com/baeldung/temporal/workflows/hellov2/activities/HelloV2Activities.java
@@ -0,0 +1,11 @@
+package com.baeldung.temporal.workflows.hellov2.activities;
+
+import io.temporal.activity.ActivityInterface;
+import io.temporal.activity.ActivityMethod;
+
+@ActivityInterface
+public interface HelloV2Activities {
+    @ActivityMethod
+    String sayHello(String person);
+    String sayGoodbye(String person);
+}
diff --git a/...c/main/java/com/baeldung/temporal/workflows/hellov2/activities/HelloV2ActivitiesImpl.java b/...c/main/java/com/baeldung/temporal/workflows/hellov2/activities/HelloV2ActivitiesImpl.java
@@ -0,0 +1,38 @@
+package com.baeldung.temporal.workflows.hellov2.activities;
+
+import io.temporal.activity.Activity;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.atomic.AtomicLong;
+
+public class HelloV2ActivitiesImpl implements HelloV2Activities {
+    private static final Logger log = LoggerFactory.getLogger(HelloV2ActivitiesImpl.class);
+
+    @Override
+    public String sayHello(String person) {
+        var info = Activity.getExecutionContext().getInfo();
+
+        log.info("Saying hello to {}, workflowId={}, attempt={}", person,
+          info.getWorkflowId(),
+          info.getAttempt());
+        return "Step1 - OK";
+    }
+
+    @Override
+    public String sayGoodbye(String person) {
+
+        var info = Activity.getExecutionContext().getInfo();
+
+        log.info("Saying goodbye to {}, workflowId={}, attempt={}", person,
+          info.getWorkflowId(),
+          info.getAttempt());
+
+        if ( info.getAttempt() == 1 ) {
+            throw new IllegalStateException("Simulating task failure");
+        }
+        else {
+            return "Step2 - OK";
+        }
+    }
+}
diff --git a/saas-modules/temporal/src/main/resources/logback.xml b/saas-modules/temporal/src/main/resources/logback.xml
@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+
+    <!-- Console appender -->
+    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <!-- Root logger -->
+    <root level="INFO">
+        <appender-ref ref="CONSOLE" />
+    </root>
+
+</configuration>