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Spring Boot Integration

The transact-spring-boot-starter package integrates DBOS into a Spring Boot application with zero boilerplate: add the dependency, configure a datasource, annotate your beans, and DBOS launches automatically alongside the Spring context.

tip

The Java Widget Store demo is a fully featured DBOS Spring Boot application that illustrates the features described in this documentation.

Adding the Dependency​

dependencies {
  implementation("dev.dbos:transact-spring-boot-starter:0.8.0")
}

Configuration​

Instead of creating the DBOSConfig for your app programmatically, the Spring Boot Starter package allows you to configure DBOS via Spring Boot External Application Properties. For example, you can set your application name and database connection in application.yaml (or application.properties):

dbos:
  application:
    name: "my-app"
  # DBOS system database 
  datasource:
    url: "jdbc:postgresql://localhost:5432/my_app_db"
    username: "postgres"
    password: "${PGPASSWORD}"

If dbos.application.name or dbos.datasource properties are not set, spring.application.name and spring.datasource are used as a fallback.

spring:
  application:
    name: "my-app"
  datasource:
    url: "jdbc:postgresql://localhost:5432/my_app_db"
    username: "postgres"
    password: "${PGPASSWORD}"
    driver-class-name: "org.postgresql.Driver"
danger

DBOS only supports PostgreSQL today. Attempting to use a non PostgreSQL database driver will throw an exception.

For a full list of DBOSConfig fields you can set via application properties, please see the reference documentation.

Programmatic Configuration​

Declare a DBOSConfigCustomizer bean to adjust the auto-configured DBOSConfig without replacing it:

@Bean
public DBOSConfigCustomizer myCustomizer() {
    return config -> config
        .withAdminServer(true)
        .withAdminServerPort(8081)
        .withEnablePatching(true);
}

Multiple DBOSConfigCustomizer beans are applied in @Order / Ordered order. To replace the config entirely, declare your own @Bean DBOSConfig.

Defining Workflows and Steps​

In "vanilla" DBOS, you need to define an interface and a class in order use @Workflow and @Step. With Spring Boot Starter, you can use the @Workflow and @Step annotations on methods on any Spring-managed singleton bean (@Service, @Component, etc.). transact-spring-boot-starter uses Spring AOP instead of dynamic proxies, which do not require defining a separate interface.

With Spring Boot Starter, you also don't need to manually register workflow and step proxies with dbos.registerProxy. The DBOSWorkflowRegistrar automatically scans all singleton beans after initialization and registers @Workflow methods automatically.

Note, that you do however still need a proxy instance for invocating @Workflow and @Step methods on the same instance. This proxy reference can be self injected via an @Autowired setter.

@Service
public class OrderService {

  private OrderService self;

  // self reference is injected automatically by Spring Boot Dependency Injection
  @Autowired 
  @Lazy
  public void setSelf(WidgetStoreService self) {
    this.self = self;
  }

  @Workflow
  public String processOrder(String orderId) {
    // Invoke @Step via self reference to perform durable execution book keeping
    String result = self.chargeCard(orderId);   
    self.sendConfirmation(orderId, result);
    return result;
  }

  @Step
  public String chargeCard(String orderId) { /* ... */ return "charged"; }

  @Step
  public void sendConfirmation(String orderId, String result) { /* ... */ }
}

Multiple Beans of the Same Class​

When multiple beans of the same class exist, the @Primary one is registered under the default (empty) instance name. Additional beans of the same class are registered as Workflow Class Instances using their Spring bean name. Use withInstanceName(String) in StartWorkflowOptions or EnqueueOptions to target a specific bean.

Lifecycle​

DBOSLifecycle is a SmartLifecycle bean that calls dbos.launch() after all singletons are initialized and dbos.shutdown() when the context closes. Schedules and queues registered in @PostConstruct methods or ApplicationListener<ContextRefreshedEvent> handlers are guaranteed to be in place before launch.

Injecting dbos instance​

The auto-configured DBOS bean is available for injection anywhere in the application:

// Constructor injection
@Service
public class WidgetStoreService {
  private final DBOS dbos;
  private final WidgetStoreRepository repo;
 
  public WidgetStoreService(DBOS dbos, WidgetStoreRepository widgetStoreRepo) {
    this.dbos = dbos;
    this.repo = widgetStoreRepo;
  }
}

// @Autowired field injection
@Service
public class ScheduleSetup implements ApplicationListener<ContextRefreshedEvent> {

    @Autowired DBOS dbos;
    @Autowired OrderService orderServiceProxy;

    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {
        dbos.applySchedules(
            new WorkflowSchedule("daily-orders", "processOrder",
                "com.example.OrderService", "0 0 9 * * *")
        );
    }
}