Moments — a Passage of Time Events API

spring-modulith-moments is a Passage of Time Events implementation heavily inspired by Matthias Verraes blog post. It’s an event-based approach to time to trigger actions that are tied to a particular period of time having passed.

To use the abstraction, include the following dependency in your project:

Maven
Gradle

<dependency>
  <groupId>org.springframework.modulith</groupId>
  <artifactId>spring-modulith-moments</artifactId>
</dependency>

dependencies {
  implementation 'org.springframework.modulith:spring-modulith-moments'
}

The dependency added to the project’s classpath causes the following things in your application:

Application code can refer to HourHasPassed, DayHasPassed, WeekHasPassed, MonthHasPassed, QuarterHasPassed, YearHasPassed types in Spring event listeners to get notified if a certain amount of time has passed.
A bean of type org.springframework.modulith.Moments is available in the ApplicationContext that contains the logic to trigger these events.
If spring.modulith.moments.enable-time-machine is set to true, that instance will be a org.springframework.modulith.TimeMachine which allows to "shift" time and by that triggers all intermediate events, which is useful to integration test functionality that is triggered by the events.

By default, Moments uses a Clock.systemUTC() instance. To customize this, declare a bean of type Clock.

Java
Kotlin

@Configuration
class MyConfiguration {

  @Bean
  Clock myCustomClock() {
    // Create a custom Clock here
  }
}

@Configuration
class MyConfiguration {

  @Bean
  fun myCustomClock(): Clock {
    // Create a custom Clock here
  }
}

Moments exposes the following application properties for advanced customization:

Table 1. Available application properties
Property	Default value	Description
`spring.modulith.moments.enable-time-machine`	false	If set to `true`, the `Moments` instance will be a `TimeMachine`, that exposes API to shift time forward. Useful for integration tests that expect functionality triggered by the Passage of Time Events.
`spring.modulith.moments.granularity`	hours	The minimum granularity of events to be fired. Alternative value `days` to avoid hourly events.
`spring.modulith.moments.locale`	`Locale.getDefault()`	The `Locale` to use when determining week boundaries.
`spring.modulith.moments.quarter-start-month`	`Months.JANUARY`	The month at which quarters start.
`spring.modulith.moments.zone-id`	`ZoneOffset#UTC`	The `ZoneId` to determine times which are attached to the events published.