Middleware allows you to execute common logic across your message listeners. Common use cases include:

• Logging and auditing job details.
• Profiling listener performance.
• Managing transaction boundaries (e.g., database transactions, New Relic, distributed tracing).
• Implementing rate limiting (e.g., restricting a queue to 10 jobs per minute).
• Ensuring sequential job execution (e.g., forcing a specific user’s tasks to run one at a time).
• Enforcing access control or handling status changes (e.g., checking for user bans).

You can register one or more middleware implementations via the SimpleRqueueListenerContainerFactory. Middleware is invoked in the order it is added, providing a structured way to intercept and process messages.

public class RqueueConfiguration {

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