In many scenarios, there’s a need to execute specific blocks of code repetitively. Some common use cases include:

• Logging job details
• Profiling listener methods
• Initiating transactions (e.g., New Relic, database, distributed transactions, Micrometer tracer)
• Implementing rate limiting (e.g., restricting a queue to process only 10 jobs per minute)
• Managing concurrent job execution (e.g., ensuring a user’s account updater job runs sequentially)
• Handling permission or role changes (e.g., reacting to user bans or role updates)

Middleware can effectively handle these situations by configuring one or more middlewares through the SimpleRqueueListenerContainerFactory object. These middlewares are invoked in the order they are added, enabling structured and consistent execution of tasks across different scenarios.

public class RqueueConfiguration {

  @Bean
  public SimpleRqueueListenerContainerFactory simpleRqueueListenerContainerFactory() {
    SimpleRqueueListenerContainerFactory factory = new SimpleRqueueListenerContainerFactory();
    factory.useMiddleware(new LoggingMiddleware());
    // add other middlewares here
    return factory;
  }
}