Scheduled tasks with @Scheduled in Spring Boot - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @Scheduled annotation in Spring Boot?

The @Scheduled annotation is used to mark a method to be executed automatically at fixed intervals or specific times, enabling scheduled tasks in a Spring Boot application.

beginner

How do you enable scheduling support in a Spring Boot application?

You enable scheduling by adding the @EnableScheduling annotation to a configuration class or the main application class.

intermediate

What are the common parameters of the @Scheduled annotation?

Common parameters include fixedRate (runs method at fixed intervals), fixedDelay (runs method after a fixed delay from last completion), and cron (runs method based on a cron expression).

intermediate

Explain the difference between fixedRate and fixedDelay in @Scheduled.

fixedRate runs the method at regular intervals regardless of how long the method takes, while fixedDelay waits until the previous execution finishes and then waits the specified delay before running again.

advanced

What is a cron expression in the context of @Scheduled?

A cron expression is a string that defines a schedule using fields for seconds, minutes, hours, day of month, month, day of week, and optionally year, allowing precise control over when a task runs.

Which annotation must be added to enable scheduling in Spring Boot?

A @EnableScheduling

B @Scheduled

C @EnableAsync

D @EnableTask

You must add @EnableScheduling to enable scheduling support. @Scheduled marks the methods to run on schedule.

What does fixedRate in @Scheduled do?

A Runs the method at fixed intervals regardless of execution time

B Runs the method after a fixed delay from last completion

C Runs the method only once

D Runs the method based on a cron expression

fixedRate runs the method at regular intervals, ignoring how long the method takes.

Which parameter of @Scheduled allows scheduling with a cron expression?

A fixedDelay

B delay

C fixedRate

D cron

The cron parameter accepts a cron expression to schedule tasks precisely.

If you want a method to run 5 seconds after the last execution finishes, which @Scheduled parameter do you use?

A fixedRate = 5000

B fixedDelay = 5000

C cron = "*/5 * * * * *"

D delay = 5000

fixedDelay waits 5 seconds after the last execution finishes before running again.

Where do you place the @Scheduled annotation?

A On a configuration class

B On the main application class

C On a method to be scheduled

D On a field variable

@Scheduled is placed on the method that should run on a schedule.

Describe how to set up a scheduled task in Spring Boot using @Scheduled.

Think about enabling scheduling and marking methods.

Explain the difference between fixedRate and fixedDelay in scheduling tasks.

Consider timing relative to method execution.