Enable features on a schedule in a Spring Boot application

In this guide, you use the time window filter to enable a feature on a schedule for a Spring Boot application.

The example used is based on the Spring Boot application introduced in the feature management quickstart. Before proceeding further, complete the quickstart to create a Spring Boot application with a Beta feature flag. Once completed, you must add a time window filter to the Beta feature flag in your App Configuration store.

Prerequisites

• Create a Spring Boot application with a feature flag.
• Add a time window filter to the feature flag

Use the time window filter

You've added a time window filter for your Beta feature flag in the prerequisites. Next, you'll use the feature flag with the time window filter in your Spring Boot application.

The spring-cloud-azure-feature-management library includes the built-in TimeWindowFilter. This filter is registered automatically when you include the feature management dependency. You don't need to register it manually.

Update the DemoApplication.java file in the package directory of your app with the following code:

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import com.azure.spring.cloud.feature.management.FeatureManager;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Bean
    public CommandLineRunner runner(FeatureManager featureManager) {
        return args -> {
            for (int i = 0; i < 10; i++) {
                System.out.println("Beta is enabled: " + featureManager.isEnabled("Beta"));
                Thread.sleep(5000);
            }
        };
    }
}

Time window filter in action

When you run the application, the configuration provider loads the Beta feature flag from Azure App Configuration. The result of the isEnabled("Beta") method will be printed to the console. If your current time is earlier than the start time set for the time window filter, the Beta feature flag will be disabled by the time window filter.

You'll see the following console outputs.

Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false

Once the start time has passed, you'll notice that the Beta feature flag is enabled by the time window filter.

You'll see the console outputs change as the Beta is enabled.

Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: false
Beta is enabled: true
Beta is enabled: true
Beta is enabled: true
Beta is enabled: true

If recurrence is enabled when you set up the time window filter, the console outputs will change to Beta is enabled: false once your current time passes the end time you set in the time window filter. However, it will change to Beta is enabled: true again according to your recurrence settings and continue this pattern until the recurrence expiration time, if set.

Next steps

To learn more about the feature filters, continue to the following documents.

Enable conditional features with feature filters

Roll out features to targeted audience