Spring Boot Best Practices for Developers

Spring Boot is a widely used and highly popular enterprise‑level high‑performance framework. Below are some best practices and tips that can improve Spring Boot applications and make them more efficient. This article is a bit long and will take some time to read fully.

1. Proper Package Directory Style

A proper package structure helps understand code and application flow easily.

Meaningful package directories can be used to build the application.

Controllers can be placed in a separate package, services in another, util classes in another, etc. This style is very convenient for small micro‑services.

For large codebases, a feature‑module‑based approach can be used, depending on requirements.

Based on Type

Based on Feature Modules

2. Use Design Patterns

Design patterns are a best practice for writing maintainable and extensible code in modern programming.

3. Use Spring Boot Starters

This is a cool feature of Spring Boot.

Starters let us add dependencies easily without listing each one individually; they bundle the required dependencies.

For example, adding spring-boot-starter-web automatically brings in Jackson, spring‑core, spring‑mvc, and spring‑boot-starter‑tomcat.

Thus we do not need to worry about adding each dependency manually.

Starters also help avoid version mismatches.

4. Use Production‑Ready Dependency Versions

Always use the latest stable GA version.

The appropriate version may vary depending on Java version, server version, application type, etc.

Do not use different versions of the same artifact; if multiple dependencies exist, always specify the version in <properties>.

5. Use Lombok

As Java developers, we may have heard of the Lombok project.

Lombok is a Java library that reduces boilerplate code and allows us to write clean code using annotations.

For example, many classes such as entities, request/response DTOs contain numerous getter and setter lines.

With Lombok, a single annotation like @Data, @Getter or @Setter can generate them.

We can also use Lombok’s logging annotations; @Slf4j is recommended.

Refer to the file for details.

6. Use Constructor Injection with Lombok

There are two types of dependency injection: constructor injection and setter injection. Additionally, the popular @Autowired field injection can be used.

We strongly recommend constructor injection because it initializes all required dependencies when the application starts.

This is very useful for unit testing.

Importantly, Lombok’s @RequiredArgsConstructor can be used to implement constructor injection.

Check the example controller for reference.

7. Use SLF4J Logging

Logging is essential.

If the application encounters problems in production, logs are the only way to find the root cause.

Therefore, consider logger, log level, and log message carefully before adding them.

Do not use System.out.print() .

It is recommended to use SLF4J together with Spring Boot’s default logging framework Logback.

Always use SLF4J’s {} placeholder syntax and avoid string interpolation in log messages, as interpolation consumes more memory.

Lombok’s @Slf4j annotation makes logger creation very easy.

In a micro‑service environment, the ELK stack can be used.

8. Controllers Should Only Handle Routing

Controllers are dedicated to routing.

They are stateless and singleton.

DispatcherServlet checks @RequestMapping on controllers.

The controller is the final entry point; it forwards the request to the service layer for processing.

Business logic should not reside in controllers.

9. Use Services to Implement Business Logic

Complete business logic includes validation, caching, etc.

It communicates with the persistence layer and receives results.

Services are also singletons.

10. Avoid NullPointerException

Use java.util.Optional to avoid NPE.

Use null‑safe libraries such as Apache Commons StringUtils .

Call equals() or equalsIgnoreCase() on known objects.

Prefer valueOf() over toString() .

Leverage IDE‑based @NotNull and @Nullable annotations.

11. Best Practices for the Collection Framework

Use appropriate collections for your data sets.

Combine forEach with Java 8 features and avoid old‑style loops.

Program to interface types rather than implementations.

Use isEmpty() instead of size() for readability.

Return empty collections instead of null.

If objects are stored in hash‑based collections, override equals() and hashCode() . See “How HashMap Works”.

12. Use Pagination

Pagination improves application performance.

When using Spring Data JPA, PagingAndSortingRepository makes pagination easy and almost effortless.

13. Use Caching

Caching is another important factor for application performance.

By default, Spring Boot provides caching via ConcurrentHashMap; it can be enabled with @EnableCaching. If the default cache is insufficient, Redis, Hazelcast, or any other distributed cache can be used.

Redis and Hazelcast are in‑memory cache solutions; database‑backed caching is also possible.

14. Use Custom Exception Handlers and Global Exception Handling

Crucial for large enterprise applications.

Beyond generic exceptions, specific error scenarios can be identified.

Exception advice can be created with @ControllerAdvice , allowing separate, meaningful exception classes.

This makes future error identification and debugging easier.

15. Use Custom Response Objects

Custom response objects can return specific data along with HTTP status codes, API codes, messages, etc.

The Builder pattern can be used to create response objects with custom attributes.

16. Remove Unnecessary Code, Variables, Methods, and Classes

Unused variable declarations occupy memory.

Delete unused methods and classes as they affect performance.

Avoid nested loops; use Map where appropriate.

17. Use Comments

Comments are a good practice.

Do not comment every line; instead write descriptive code and add meaningful comments to classes, functions, methods, and variables.

Remove commented‑out code, misleading comments, and story‑type comments.

Use comments for warnings and to explain code that is hard to understand at first glance.

18. Use Meaningful Words for Classes, Methods, Functions, Variables, and Other Attributes

Simple naming has a huge impact.

Always use correct, searchable naming conventions and proper case.

Typically, nouns or short phrases are used for classes, variables, and constants (e.g., String firstName , boolean isValid ).

Verbs with adjectives can represent functions and methods (e.g., readFile() , sendData() ).

Avoid obscure abbreviations (e.g., int i , String getExUsr ).

Meaningful names reduce the need for extra comment lines and make the code easier for new developers to understand.

19. Use Correct Case for Declarations

There are many case styles such as upper case, lower case, camelCase, PascalCase, snake_case, SCREAMING_SNAKE_CASE, kebab-case, etc.

We need to decide which case to use for which variable.

Typically, I follow:

Classes – PascalCase

Methods and variables – camelCase

Constants – SCREAMING_SNAKE_CASE

Database‑related fields – kebab-case

This is just an example; it may differ from the standards followed in your company.

20. Keep It Simple

Always try to write simple, readable code.

The same simple logic can be implemented in many ways, but unreadable or incomprehensible code is hard to understand.

Complex logic may consume more memory.

When coding, try to follow KISS, DRY, and SOLID principles. I will explain these in future articles.

21. Use a Common Code Formatting Style

Formatting style varies among developers. Changing coding style is considered a change and can make code merges difficult.

To avoid this, teams can adopt a common formatting style.

22. Use SonarLint Plugin

This is useful for identifying small errors and best practices, helping avoid unnecessary mistakes and code‑quality issues.

The plugin can be installed in your favorite IDE.

Conclusion

This concludes the article. Thank you for reading; I hope it helps you.

<section>
    <strong>Backend Exclusive Technical Group</strong><br/>
  </section>
  <p>Build a high‑quality technical communication community; developers, technical recruiters, and anyone willing to share internal job referrals are welcome to join, help each other, and progress together!</p>
  <blockquote>
    <p>Civilized speech, focusing on <code>technology exchange</code>, <code>job referrals</code>, and <code>industry discussion</code>.</p>
  </blockquote>
  <p>Advertisers, please do not join; do not trust private messages to avoid scams.</p>
  <p style="text-align: center"><img src="https://mmbiz.qpic.cn/mmbiz_png/eQPyBffYbueajSpgMK5FJS5nP7jkE3zUoymn48ePyttvTPbyXpvDXm9tbOXx0yfoaTibGtPAu6Ez1Y0icO2occHg/640?wx_fmt=png" style="width: 200px !important"/></p>
  <p>Add me as a friend, and I will add you to the group.</p>