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How Java Developers can Benefit from Kotlin!

·3 mins
SoftwareDevelopment Java Kotlin OotBD

Why should Java developers care about other languages, especially Kotlin? Explore how Java developers can leverage Kotlin to enhance their skills and broaden their horizons.

The July 23, 2024 episode of the “The Out of the Box Developer” with Lucas Fugisawa, a Kotlin expert and community leader was full of insights.

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Lucas Fugisawa, a software engineer and initiator of the Kotlin Devs Brasil, shared his experience and insights about Kotlin’s evolution, features, and its relationship with Java.

What is Kotlin? #

Kotlin is a general-purpose programming language developed by JetBrains that offers:

  • Strong and static typing
  • Code safety and conciseness
  • Full Java interoperability
  • Multi-platform capabilities (JVM, Native, JavaScript, WebAssembly)
  • First-class support for Android development since 2019

“Kotlin had a unique opportunity that many other languages didn’t have - it got to mature for more than five years before its first final release.” - Lucas Fugisawa

Top 3 Kotlin Features That Stand Out #

  1. Null Safety

    • Built-in null handling at the type system level
    • Different types for nullable and non-nullable variables
    • Eliminates most NullPointerException scenarios

  2. Coroutines

    • Powerful structured concurrency implementation
    • Makes async programming feel synchronous
    • More intuitive than Java’s virtual threads

  3. Extension Functions

    • Ability to add functionality to existing classes without inheritance
    • Clean alternative to utility classes
    • Enables powerful DSL creation

Java Interoperability #

One of Kotlin’s strongest features is its seamless integration with Java:

  • Direct import and use of Java libraries
  • Kotlin code can be called from Java (with some considerations)
  • Compatible with popular build tools (Gradle, Maven)
  • Shares the same ecosystem benefits

Making the Switch: Tips for Java Developers #

To write idiomatic Kotlin code:

  • Embrace Kotlin-specific features rather than writing “Java-style” code
  • Learn functional programming concepts
  • Utilize Kotlin’s more expressive syntax
  • Take advantage of properties instead of traditional getters/setters

“Kotlin’s true power only shines when we really use its unique features, not just writing Java-style code in Kotlin syntax.” - Lucas Fugisawa

Migration Success Story #

At ClassPass, where Lucas works:

  • Successfully migrating from Python and Java to Kotlin
  • New services are built directly in Kotlin
  • Version upgrades are typically smooth (2-hour process)
  • Developers report high satisfaction levels

Key Takeaways #

  1. Kotlin offers modern language features while maintaining Java compatibility
  2. The learning curve is manageable for Java developers
  3. Community support and tooling are robust
  4. Migration can be gradual and straightforward
  5. The language continues to evolve with developer needs in mind

Resources to Get Started #

  • Join the Kotlin community: kotlinbr.dev
  • Follow Lucas’s blog: fugisawa.com
  • Explore official Kotlin documentation
  • Try converting simple Java code to Kotlin using IDE tools

Whether you’re considering Kotlin for Android development, backend services, or full-stack applications, the language offers a modern, safe, and expressive alternative to Java while maintaining familiar ecosystem benefits.

Want to learn more about Kotlin? Join the Brazilian Kotlin community at kotlinbr.dev or follow Lucas Fugisawa’s blog for insights and best practices.

YouTube link to the original session