Course – Black Friday 2025 – NPI EA (cat= Baeldung)
announcement - icon

Yes, we're now running our Black Friday Sale. All Access and Pro are 33% off until 2nd December, 2025:

>> EXPLORE ACCESS NOW

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

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

Partner – Orkes – NPI EA (tag=Microservices)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

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 – 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

Partner – Orkes – NPI EA (cat=Java)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

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 – Black Friday 2025 – NPI (cat=Baeldung)
announcement - icon

Yes, we're now running our Black Friday Sale. All Access and Pro are 33% off until 2nd December, 2025:

>> EXPLORE ACCESS NOW

1. Overview

Java stores Integer using 32 bits of memory. Thus, Integer‘s(or int‘s) range is from -231 (-2,147,483,648) to 231-1 (2,147,483,647)Therefore, when we see an error message like “java: integer number too large …“, we can usually easily find the problem and fix it.

However, in some cases, when we see this error message, we might not understand why the error occurred. And it’ll take some time to fix the problem.

So, in this tutorial, we’ll take a closer look at a couple of pitfalls that lead to this error and address the reason behind the error.

2. Integer Literals Pitfall #1

The Java compiler complains when we assign a literal number out of the mentioned integer range to an int variable. For example, let’s say we compile this assignment:

int a = 12345678912345;

The compiler reports this error:

java: integer number too large

We can quickly find the problem by reading the error message. We may think int is not the right type for such a big number, so we change the type to long:

long a = 12345678912345;

However, when we recompile the code, we get the same compilation error: “integer number too large“. We’ll wonder why the compiler still complains about integer, although we declared the variable as long? Next, we may spend some time double-checking if we saved the file correctly or restarting the IDE, and so on. However, the problem still stays.

When we write number literals in Java, no matter whether it’s within or outside the integer range, Java treats it as the Integer/int type. If we want an integer literal to be long, we must add the ‘L‘ or ‘l‘ suffix. This is also explicitly stated in the Java Language Specification:

An integer literal is of type long if it is suffixed with an ASCII letter L or l (ell); otherwise it is of type int

Therefore, to fix the problem, we should add an ‘L‘ after the literal number:

long a = 12345678912345L;

It’s worth mentioning when we use decimal literals without any suffix, Java treats them as double. In case we want them to be float, we must add an ‘F‘ or ‘f‘ suffix:

float a = 1024.42; // compiler error -  java: incompatible types: possible lossy conversion from double to float
float a = 1024.42F; // compiled

3. Integer Literals Pitfall #2

Now we understand that we should add the ‘L‘ suffix to integer literals for the long type. Next, let’s see another example:

long a = 007L;

As the code above shows, we have the suffix ‘L‘ this time, and a‘s type is long. The code compiles smoothly even if there are leading zeros. If we check a’s value, the variable a holds 7, as expected. So, we may think Java is so intelligent that it ignores the leading zeros of numbers.

Now, let’s declare another variable:

long b = 008L;

Again, the compiler reports “integer number too large” if we compile the code.

This time, there’s no sign of an integer in our code. Furthermore, long a = 007L; has worked without any problem. Why does long b = 008L fail? It may take some time to solve the problem.

Actually, we’ve fallen into another integer literals pitfall. This is because, in Java, an integer literal can also be expressed in octal (base 8). Further, an octal integer consists of a leading zero followed by one or more of the digits 0 through 7.

Therefore, everything’s fine when we assign ‘007L‘ to a variable. This is because Java reads the octal integer literal ‘007′, and treats it as long. However, when we assign ‘008L‘ to a variable, 008 is not a valid octal integer. Thus, the compiler reports that error.

After we understand the cause of the problem, the fix is pretty simple – removing the leading zeros:

long b = 8L;

4. Conclusion

In this article, we’ve discussed two common pitfalls when we work with integer literals in Java.

Understanding the reason behind the compilation error may help us find and fix the problem quickly.

Course – Black Friday 2025 – NPI EA (cat= Baeldung)
announcement - icon

Yes, we're now running our Black Friday Sale. All Access and Pro are 33% off until 2nd December, 2025:

>> EXPLORE ACCESS NOW

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

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

Partner – Orkes – NPI EA (tag = Microservices)
announcement - icon

Modern software architecture is often broken. Slow delivery leads to missed opportunities, innovation is stalled due to architectural complexities, and engineering resources are exceedingly expensive.

Orkes is the leading workflow orchestration platform built to enable teams to transform the way they develop, connect, and deploy applications, microservices, AI agents, and more.

With Orkes Conductor managed through Orkes Cloud, developers can focus on building mission critical applications without worrying about infrastructure maintenance to meet goals and, simply put, taking new products live faster and reducing total cost of ownership.

Try a 14-Day Free Trial of Orkes Conductor today.

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 – Black Friday 2025 – NPI (All)
announcement - icon

Yes, we're now running our Black Friday Sale. All Access and Pro are 33% off until 2nd December, 2025:

>> EXPLORE ACCESS NOW

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