Common Utilities

Codion provides a few classes with miscellanous utility functions.

1. Core

2. TaskScheduler

TaskScheduler provides a simple, lightweight way to execute tasks periodically on a background thread.

2.1. Basic Usage

Create a scheduler that runs a task at fixed intervals:

// Build a scheduler that runs a task every 5 seconds
TaskScheduler scheduler =
        TaskScheduler.builder()
                .task(() -> System.out.println("Running scheduled task"))
                .interval(5, TimeUnit.SECONDS)
                .initialDelay(10) // Wait 10 seconds before first execution
                .name("My Task Scheduler") // Name for debugging
                .build();

// Start the scheduler
scheduler.start();

// Check if it's running
boolean running = scheduler.running();

// Stop the scheduler when done
scheduler.stop();

2.2. Auto-Start

Use the start() method to build and start the scheduler in one step:

// Build and start in one step
TaskScheduler scheduler =
        TaskScheduler.builder()
                .task(this::performMaintenance)
                .interval(30, TimeUnit.SECONDS)
                .name("Maintenance Task")
                .start(); // Builds and starts immediately

2.3. Thread Naming

The name() method sets the thread name, which is useful for debugging and thread dumps:

TaskScheduler scheduler =
    TaskScheduler.builder()
        .task(maintenanceTask)
        .interval(30, TimeUnit.SECONDS)
        .name("Connection Maintenance") // Appears in thread dumps
        .start();

Tip	Always name your scheduler threads descriptively to make debugging easier.

2.4. Custom ThreadFactory

For advanced control over thread creation, provide a custom ThreadFactory:

// Use a custom ThreadFactory for advanced control
TaskScheduler scheduler =
        TaskScheduler.builder()
                .task(() -> System.out.println("Custom thread task"))
                .interval(1, TimeUnit.MINUTES)
                .threadFactory(runnable -> {
                  Thread thread = new Thread(runnable);
                  thread.setDaemon(true);
                  thread.setPriority(Thread.MIN_PRIORITY);
                  thread.setName("Custom Task Thread");
                  return thread;
                })
                .start();

Note	When using a custom `threadFactory()`, the `name()` setting is ignored since the ThreadFactory has full control over thread creation.

2.5. Common Use Cases

TaskScheduler is ideal for:

Connection maintenance - Periodically cleaning up idle connections
Cache cleanup - Removing stale cache entries
Statistics collection - Gathering metrics at regular intervals
Health checks - Monitoring system health
Periodic saves - Auto-saving user preferences or state

All scheduler threads are daemon threads by default, so they won’t prevent JVM shutdown.

3. UI