Cron expressions for scheduling in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to schedule a method to run every minute using a cron expression.

Spring Boot

@Scheduled(cron = "[1]")
public void runEveryMinute() {
    System.out.println("Running every minute");
}

Drag options to blanks, or click blank then click option'

A"* * * * *"

B"*/5 * * * * ?"

C"0 0/1 * * * ?"

D"0 * * * * *"

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 fields instead of 6 in the cron expression

Setting the wrong field for seconds

The cron expression "0 * * * * *" means the method runs at the 0th second of every minute.

2fill in blank

medium

Complete the cron expression to schedule a task to run at 3:30 AM every day.

Spring Boot

@Scheduled(cron = "[1]")
public void runDailyAt330() {
    System.out.println("Running daily at 3:30 AM");
}

Drag options to blanks, or click blank then click option'

A"30 0 3 * * *"

B"0 30 3 * * *"

C"0 3 30 * * *"

D"0 30 15 * * *"

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping minutes and hours

Using 24-hour format incorrectly

The cron expression "0 30 3 * * *" means at second 0, minute 30, hour 3 every day.

3fill in blank

hard

Fix the error in the cron expression to run a task every Monday at 8 AM.

Spring Boot

@Scheduled(cron = "[1]")
public void runEveryMondayAt8() {
    System.out.println("Running every Monday at 8 AM");
}

Drag options to blanks, or click blank then click option'

A"0 0 8 ? * MON"

B"0 0 8 * * MON"

C"0 0 8 * * 1"

D"0 0 8 ? * 2"

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' instead of '?' for day-of-month

Using numeric day-of-week incorrectly

In Spring cron, '?' is used for day-of-month when specifying day-of-week. "0 0 8 ? * MON" runs at 8 AM every Monday.

4fill in blank

hard

Fill both blanks to schedule a task to run every 15 minutes between 9 AM and 5 PM on weekdays.

Spring Boot

@Scheduled(cron = "[1] [2] 9-17 * * MON-FRI")
public void runEvery15MinWeekdays() {
    System.out.println("Running every 15 minutes on weekdays between 9 AM and 5 PM");
}

Drag options to blanks, or click blank then click option'

A0

B0/15

C9-17

D*/15

Attempts:

3 left

💡 Hint

Common Mistakes

Using '*' for seconds causing multiple triggers

Incorrect hour range or day specification

The expression "0 0/15 9-17 * * MON-FRI" means at second 0, every 15 minutes, hours 9 to 17, Monday to Friday.

5fill in blank

hard

Fill all three blanks to schedule a task to run at 10:15 PM on the last day of every month.

Spring Boot

@Scheduled(cron = "[1] [2] [3] L * ?")
public void runMonthlyLastDay() {
    System.out.println("Running at 10:15 PM on the last day of every month");
}

Drag options to blanks, or click blank then click option'

A0

B15

C22

D59

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong hour or minute values

Misplacing 'L' in the expression

The cron expression "0 15 22 L * ?" means at second 0, minute 15, hour 22 (10 PM), on the last day (L) of every month.