eBook – Guide Spring Cloud – NPI EA (cat=Spring Cloud)
announcement - icon

Let's get started with a Microservice Architecture with Spring Cloud:

>> Join Pro and download the eBook

eBook – Mockito – NPI EA (tag = Mockito)
announcement - icon

Mocking is an essential part of unit testing, and the Mockito library makes it easy to write clean and intuitive unit tests for your Java code.

Get started with mocking and improve your application tests using our Mockito guide:

Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
announcement - icon

Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

>> Download the eBook

eBook – Reactive – NPI EA (cat=Reactive)
announcement - icon

Spring 5 added support for reactive programming with the Spring WebFlux module, which has been improved upon ever since. Get started with the Reactor project basics and reactive programming in Spring Boot:

>> Join Pro and download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
announcement - icon

Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

>> Join Pro and download the eBook

eBook – Jackson – NPI EA (cat=Jackson)
announcement - icon

Do JSON right with Jackson

Download the E-book

eBook – HTTP Client – NPI EA (cat=Http Client-Side)
announcement - icon

Get the most out of the Apache HTTP Client

Download the E-book

eBook – Maven – NPI EA (cat = Maven)
announcement - icon

Get Started with Apache Maven:

Download the E-book

eBook – Persistence – NPI EA (cat=Persistence)
announcement - icon

Working on getting your persistence layer right with Spring?

Explore the eBook

eBook – RwS – NPI EA (cat=Spring MVC)
announcement - icon

Building a REST API with Spring?

Download the E-book

Course – LS – NPI EA (cat=Jackson)
announcement - icon

Get started with Spring and Spring Boot, through the Learn Spring course:

>> LEARN SPRING
Course – RWSB – NPI EA (cat=REST)
announcement - icon

Explore Spring Boot 3 and Spring 6 in-depth through building a full REST API with the framework:

>> The New “REST With Spring Boot”

Course – LSS – NPI EA (cat=Spring Security)
announcement - icon

Yes, Spring Security can be complex, from the more advanced functionality within the Core to the deep OAuth support in the framework.

I built the security material as two full courses - Core and OAuth, to get practical with these more complex scenarios. We explore when and how to use each feature and code through it on the backing project.

You can explore the course here:

>> Learn Spring Security

Course – LSD – NPI EA (tag=Spring Data JPA)
announcement - icon

Spring Data JPA is a great way to handle the complexity of JPA with the powerful simplicity of Spring Boot.

Get started with Spring Data JPA through the guided reference course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (cat=Spring Boot)
announcement - icon

Refactor Java code safely — and automatically — with OpenRewrite.

Refactoring big codebases by hand is slow, risky, and easy to put off. That’s where OpenRewrite comes in. The open-source framework for large-scale, automated code transformations helps teams modernize safely and consistently.

Each month, the creators and maintainers of OpenRewrite at Moderne run live, hands-on training sessions — one for newcomers and one for experienced users. You’ll see how recipes work, how to apply them across projects, and how to modernize code with confidence.

Join the next session, bring your questions, and learn how to automate the kind of work that usually eats your sprint time.

Course – LJB – NPI EA (cat = Core Java)
announcement - icon

Code your way through and build up a solid, practical foundation of Java:

>> Learn Java Basics

1. Overview

Cron expressions enable us to schedule tasks to run periodically at a specific date and time. After its introduction in Unix, other Unix-based operating systems and software libraries (including the Spring Framework) adopted its approach for task scheduling.

In this quick tutorial, we’re going to see what’s the difference between Cron expressions in Unix-based operating systems and the Spring Framework.

2. Unix Cron

Cron in most Unix-based systems has five fields: minute (0-59), hour (0-23), day of the month (1-31), months (1-12 or names), and day of the week (0-7 or names).

We can put some special values in each field, like an asterisk (*):

5 0 * * *

The job will be executed 5 minutes after midnight every day. It’s also possible to use a range of values:

5 0-5 * * *

Here the scheduler will execute the task 5 minutes after midnight, and also 5 minutes after 1, 2, 3, 4, and 5 o’clock every day.

Or, we can use a list of values:

5 0,3 * * *

Now the scheduler executes the job five minutes after midnight and five minutes after 3 o’clock every day. The original Cron expression offers many more features than what we covered so far.

However, it comes with one big limitation: We can’t schedule jobs with second precision since it doesn’t have a dedicated second field.

Let’s see how Spring manages to fix this limitation.

3. Spring Cron

To schedule periodic background tasks in Spring, we usually pass a Cron expression to the @Scheduled annotation.

As opposed to Cron expressions in Unix-based systems, the Cron expression in Spring has six space-separated fields: second, minute, hour, day, month, and weekday.

For instance, to run a task every ten seconds we can do:

*/10 * * * * *

Also, to run a task every 20 seconds from 8 am to 10m every day:

*/20 * 8-10 * * *

As shown in the above examples, the first field represents the second portion of the expression. That’s the difference between the two implementations. Despite the difference in the second field, Spring supports many features from the original Cron such as range numbers or lists.

From the implementation’s perspective, the CronSequenceGenerator class is responsible for parsing the Cron expressions in Spring.

4. Conclusion

In this short tutorial, we saw the Cron implementation difference between Spring and most Unix-based systems. Along the way, we saw a few examples of both implementations.

In order to see more examples of Cron expressions, it’s highly recommended to check out our Guide to Cron Expressions. Moreover, taking a look at the source code of the CronSequenceGenerator class can give us a good idea of how Spring implements this feature.

Baeldung Pro – NPI EA (cat = Baeldung)
announcement - icon

Baeldung Pro comes with both absolutely No-Ads as well as finally with Dark Mode, for a clean learning experience:

>> Explore a clean Baeldung

Once the early-adopter seats are all used, the price will go up and stay at $33/year.

eBook – HTTP Client – NPI EA (cat=HTTP Client-Side)
announcement - icon

The Apache HTTP Client is a very robust library, suitable for both simple and advanced use cases when testing HTTP endpoints. Check out our guide covering basic request and response handling, as well as security, cookies, timeouts, and more:

>> Download the eBook

eBook – Java Concurrency – NPI EA (cat=Java Concurrency)
announcement - icon

Handling concurrency in an application can be a tricky process with many potential pitfalls. A solid grasp of the fundamentals will go a long way to help minimize these issues.

Get started with understanding multi-threaded applications with our Java Concurrency guide:

>> Download the eBook

eBook – Java Streams – NPI EA (cat=Java Streams)
announcement - icon

Since its introduction in Java 8, the Stream API has become a staple of Java development. The basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use.

But these can also be overused and fall into some common pitfalls.

To get a better understanding on how Streams work and how to combine them with other language features, check out our guide to Java Streams:

>> Join Pro and download the eBook

eBook – Persistence – NPI EA (cat=Persistence)
announcement - icon

Working on getting your persistence layer right with Spring?

Explore the eBook

Course – LS – NPI EA (cat=REST)

announcement - icon

Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

Partner – Moderne – NPI EA (tag=Refactoring)
announcement - icon

Modern Java teams move fast — but codebases don’t always keep up. Frameworks change, dependencies drift, and tech debt builds until it starts to drag on delivery. OpenRewrite was built to fix that: an open-source refactoring engine that automates repetitive code changes while keeping developer intent intact.

The monthly training series, led by the creators and maintainers of OpenRewrite at Moderne, walks through real-world migrations and modernization patterns. Whether you’re new to recipes or ready to write your own, you’ll learn practical ways to refactor safely and at scale.

If you’ve ever wished refactoring felt as natural — and as fast — as writing code, this is a good place to start.

Course – LS – NPI – (cat=Spring)
announcement - icon

Get started with Spring Boot and with core Spring, through the Learn Spring course:

>> CHECK OUT THE COURSE

eBook Jackson – NPI EA – 3 (cat = Jackson)